Wednesday, 31 August 2016
File under "well said" XXXIV
Success consists of going from failure to failure without loss of enthusiasm.
Winston Churchill
Winston Churchill
The talking ape continues to testify against Darwinism
In The Kingdom of Speech, Tom Wolfe Tells the Story of Evolution's Epic Tumble.
David Klinghoffer
Darwinian evolution explains biological trivia -- variable finch beaks and the like -- but stumbles when it comes to the major innovations in the long history of life. No innovation could be more revolutionary than how homo sapiens, as Discovery Institute biologist Michael Denton puts it, "slipped suddenly into being on the rich, game-laden African grasslands of the late Pleistocene."The most distinctive thing about man is of course his gift for language. On that, the great Tom Wolfe masterfully explains in a new book out today, Darwinism takes an epic tumble. Evolution cannot explain the very thing that preeminently makes us human. "To say that animals evolved into man," writes Wolfe on the last page of The Kingdom of Speech, "is like saying that Carrara marble evolved into Michelangelo's David."
The analogy is heavy with significance. An artist shapes his medium as an act of deliberate design. Wolfe, one of the most treasured writers alive today, hasn't come out for intelligent design, at least not directly. In previous statements he has shown sympathy for ID, comparing the persecution of ID scientists to the "Spanish Inquisition." Here too he refers to the "Neo-Darwinist Inquisition." But his focus is on the story of how evolution, from Darwin to Chomsky, came up short in explaining speech. He lets the implications of this speak for themselves.
The significance of speech goes beyond merely expressing our exceptional status as humans -- the "cardinal distinction between man and animal." As Wolfe points out, it grants us rule over the earth and its creatures, and even more than that.
In short, speech, and only speech, has enabled us human beasts to conquer every square inch of land in the world, subjugate every creature big enough to lay eyes on, and eat up half the population of the sea.
And this, the power to conquer the entire planet for our own species, is the minor achievement of speech's great might. The great achievement has been the creation of an internal self, an ego.
From that "internal self," endowed with curiosity and longing, flows the riches of civilization -- art, religion, philosophy, literature, science, and so much more. How impressive, really, is a theory of origins if it can shed no light on the origin of any of that?
Wolfe frames his story in terms of two pairs of rivals or doppelgängers -- Charles Darwin and Alfred Russel Wallace, on one hand, and linguists Noam Chomsky and Daniel Everett on the other. As in every other book of his that I've read, Wolfe is sharply attuned to matters of status, rank, class -- which explain so much not only in fashion or politics but in the history of ideas. In both of these pairs of scientists, one is the established figure, the man of rank and prestige (Darwin, Chomsky), while he was overtaken and nearly knocked from his pedestal by a field researcher of lesser cachet (Wallace, Everett), a "flycatcher" in Wolfe's phrase.
In 1858, Wallace panicked Darwin into going public with his theory, which Wallace had thought up independently while in a malarial swoon on the other side of the world. The co-discoverer of evolution by natural selection came later to reject the comprehensive explanatory power of his and Darwin's theory.
Wallace showed, writes Wolfe, that "natural selection can expand a creature's powers only to the point where it has an advantage over the competition in the struggle for existence." What's more, "natural selection can't produce any 'specially developed organ' that is useless to a creature...or of so little use that it is not until thousands and thousands of years down the line that the creature can take advantage of the organ's full power."
Speech is the most obvious example of a power inexplicable in terms of natural selection. Only a designer could look ahead that way, using foresight and working out a plan, which led Wallace to his proto-intelligent design view, arguing for "the agency of some other power," "a superior intelligence," a "controlling intelligence," at work in guiding evolution. Darwin, meanwhile, was left to speculate absurdly about speech being an extension of bird song.
And there the matter was left until Chomsky came on the scene in the 1950s with his own notion of an evolved language "organ," hidden somewhere, as yet undetected, in the brain. Known as much for this theory as for his "Radical Chic" (Wolfe's famous phrase) politics, Chomsky intimidated his field and looked askance at "flycatchers" who left the air-conditioned department building to investigate obscure languages in obscure, inconvenient, and unhygienic parts of the world.
Chomsky's theory reigned supreme until 2008 when a flycatcher, Daniel Everett, revealed a primitive language, that of the Pirahã, a people of the Amazon, that lacked a key linguistic feature (recursion) that Chomsky held to be universal. It must be universal if a shared, evolved "organ" was responsible for all human speech. The conclusion of Everett's research was that speech, not a product of evolution, was in truth an "artifact" of human devising.
The study of linguistics was thrown into chaos. Chomsky himself, even as he all but denied the existence of his rival, was compelled to admit that after decades of his labor, "The evolution of the faculty of language largely remains an enigma":
[I]n thirty years, Chomsky had advanced from "specific neural structures, though their nature is not well understood" to "some rather obscure system of thought that we know is there but we don't know much about it."
We hardly understand language today, what it is, any better today than Aristotle, who explained it as a system of "mnemonics," an aid to memory.
The Kingdom of Speech is a brief, wonderfully written book, often hilarious. The bits about Darwin's dog and Chomsky's "visiting Martian" (a fixture of his lectures), for example, are delicious. The role of social prestige, not science, in accounting for a failed idea's persistence is a theme that nobody is better suited to explore than Tom Wolfe. He tells how in Darwin's own day, "people began to judge one another socially according to their belief, or not, in Darwin's great discovery." How little has changed!
Wolfe, it's true, does not pull the obvious trigger. He fairly begs to be introduced to Michael Denton. If speech is an artifact, how did man acquire the capacity to devise and use it? As Dr. Denton writes in his recent book, Evolution: Still a Theory in Crisis, the exalted intellectual capacities shared by men and women of all races, and accessed only through language, probably were not much use in hunting mammoths. He writes:
One of the most curious features of human evolution, and one that poses at the outset an intriguing and still unanswered challenge to the Darwinian and functionalist narrative, is the fact that all modern humans share the same higher intellectual capabilities. This means, incredible though it may seem, a brain capable of the intellectual feats of an Einstein, a Newton, or a Mozart must have already emerged in our last common ancestors more than 200,000 years ago. Such intellectual abilities seem absurdly powerful, beyond any conceivable utility for hunter-gatherers on that ancient savanna, and hence beyond any functionalist explanation.
Language, Denton writes, the "Type-defining homolog," is "consistent with a saltational origin." In other words, it appears to have sprung into existence, "slipped suddenly into being," from no primitive or animal model before it.
Alfred Wallace, as ever, pointed the way. Such a power, coming into existence when it could not possibly serve an evolutionary purpose, can only be accounted for as the product of design. Wolfe prefers to let us pull that trigger for ourselves.
David Klinghoffer
Darwinian evolution explains biological trivia -- variable finch beaks and the like -- but stumbles when it comes to the major innovations in the long history of life. No innovation could be more revolutionary than how homo sapiens, as Discovery Institute biologist Michael Denton puts it, "slipped suddenly into being on the rich, game-laden African grasslands of the late Pleistocene."The most distinctive thing about man is of course his gift for language. On that, the great Tom Wolfe masterfully explains in a new book out today, Darwinism takes an epic tumble. Evolution cannot explain the very thing that preeminently makes us human. "To say that animals evolved into man," writes Wolfe on the last page of The Kingdom of Speech, "is like saying that Carrara marble evolved into Michelangelo's David."
The analogy is heavy with significance. An artist shapes his medium as an act of deliberate design. Wolfe, one of the most treasured writers alive today, hasn't come out for intelligent design, at least not directly. In previous statements he has shown sympathy for ID, comparing the persecution of ID scientists to the "Spanish Inquisition." Here too he refers to the "Neo-Darwinist Inquisition." But his focus is on the story of how evolution, from Darwin to Chomsky, came up short in explaining speech. He lets the implications of this speak for themselves.
The significance of speech goes beyond merely expressing our exceptional status as humans -- the "cardinal distinction between man and animal." As Wolfe points out, it grants us rule over the earth and its creatures, and even more than that.
In short, speech, and only speech, has enabled us human beasts to conquer every square inch of land in the world, subjugate every creature big enough to lay eyes on, and eat up half the population of the sea.
And this, the power to conquer the entire planet for our own species, is the minor achievement of speech's great might. The great achievement has been the creation of an internal self, an ego.
From that "internal self," endowed with curiosity and longing, flows the riches of civilization -- art, religion, philosophy, literature, science, and so much more. How impressive, really, is a theory of origins if it can shed no light on the origin of any of that?
Wolfe frames his story in terms of two pairs of rivals or doppelgängers -- Charles Darwin and Alfred Russel Wallace, on one hand, and linguists Noam Chomsky and Daniel Everett on the other. As in every other book of his that I've read, Wolfe is sharply attuned to matters of status, rank, class -- which explain so much not only in fashion or politics but in the history of ideas. In both of these pairs of scientists, one is the established figure, the man of rank and prestige (Darwin, Chomsky), while he was overtaken and nearly knocked from his pedestal by a field researcher of lesser cachet (Wallace, Everett), a "flycatcher" in Wolfe's phrase.
In 1858, Wallace panicked Darwin into going public with his theory, which Wallace had thought up independently while in a malarial swoon on the other side of the world. The co-discoverer of evolution by natural selection came later to reject the comprehensive explanatory power of his and Darwin's theory.
Wallace showed, writes Wolfe, that "natural selection can expand a creature's powers only to the point where it has an advantage over the competition in the struggle for existence." What's more, "natural selection can't produce any 'specially developed organ' that is useless to a creature...or of so little use that it is not until thousands and thousands of years down the line that the creature can take advantage of the organ's full power."
Speech is the most obvious example of a power inexplicable in terms of natural selection. Only a designer could look ahead that way, using foresight and working out a plan, which led Wallace to his proto-intelligent design view, arguing for "the agency of some other power," "a superior intelligence," a "controlling intelligence," at work in guiding evolution. Darwin, meanwhile, was left to speculate absurdly about speech being an extension of bird song.
And there the matter was left until Chomsky came on the scene in the 1950s with his own notion of an evolved language "organ," hidden somewhere, as yet undetected, in the brain. Known as much for this theory as for his "Radical Chic" (Wolfe's famous phrase) politics, Chomsky intimidated his field and looked askance at "flycatchers" who left the air-conditioned department building to investigate obscure languages in obscure, inconvenient, and unhygienic parts of the world.
Chomsky's theory reigned supreme until 2008 when a flycatcher, Daniel Everett, revealed a primitive language, that of the Pirahã, a people of the Amazon, that lacked a key linguistic feature (recursion) that Chomsky held to be universal. It must be universal if a shared, evolved "organ" was responsible for all human speech. The conclusion of Everett's research was that speech, not a product of evolution, was in truth an "artifact" of human devising.
The study of linguistics was thrown into chaos. Chomsky himself, even as he all but denied the existence of his rival, was compelled to admit that after decades of his labor, "The evolution of the faculty of language largely remains an enigma":
[I]n thirty years, Chomsky had advanced from "specific neural structures, though their nature is not well understood" to "some rather obscure system of thought that we know is there but we don't know much about it."
We hardly understand language today, what it is, any better today than Aristotle, who explained it as a system of "mnemonics," an aid to memory.
The Kingdom of Speech is a brief, wonderfully written book, often hilarious. The bits about Darwin's dog and Chomsky's "visiting Martian" (a fixture of his lectures), for example, are delicious. The role of social prestige, not science, in accounting for a failed idea's persistence is a theme that nobody is better suited to explore than Tom Wolfe. He tells how in Darwin's own day, "people began to judge one another socially according to their belief, or not, in Darwin's great discovery." How little has changed!
Wolfe, it's true, does not pull the obvious trigger. He fairly begs to be introduced to Michael Denton. If speech is an artifact, how did man acquire the capacity to devise and use it? As Dr. Denton writes in his recent book, Evolution: Still a Theory in Crisis, the exalted intellectual capacities shared by men and women of all races, and accessed only through language, probably were not much use in hunting mammoths. He writes:
One of the most curious features of human evolution, and one that poses at the outset an intriguing and still unanswered challenge to the Darwinian and functionalist narrative, is the fact that all modern humans share the same higher intellectual capabilities. This means, incredible though it may seem, a brain capable of the intellectual feats of an Einstein, a Newton, or a Mozart must have already emerged in our last common ancestors more than 200,000 years ago. Such intellectual abilities seem absurdly powerful, beyond any conceivable utility for hunter-gatherers on that ancient savanna, and hence beyond any functionalist explanation.
Language, Denton writes, the "Type-defining homolog," is "consistent with a saltational origin." In other words, it appears to have sprung into existence, "slipped suddenly into being," from no primitive or animal model before it.
Alfred Wallace, as ever, pointed the way. Such a power, coming into existence when it could not possibly serve an evolutionary purpose, can only be accounted for as the product of design. Wolfe prefers to let us pull that trigger for ourselves.
Speaking up in behalf of speaking out.
University of Chicago President Decries "Efforts to Suppress Discussion of Charles Darwin's Work"
Sarah Chaffee
Attempts to limit free speech on college campuses are many -- for example, at Yale, students berated professor Nicholas Christakis after he suggested that the school shouldn't regulate Halloween costumes that were not culturally sensitive.
Someone finally decided to stand up and defend freedom of speech as a defining principle of education. This summer, the University of Chicago's Dean of Students, John Ellison, sent a letter to all incoming freshman, stating:
Once here you will discover that one of the University of Chicago's defining characteristics is our commitment to freedom of inquiry and expression. This is captured in the University's faculty report on freedom of expression. Members of our community are encouraged to speak, write, listen, challenge, and learn, without fear of censorship. Civility and mutual respect are vital to all of us, and freedom of expression does not mean the freedom to harass or threaten others. You will find that we expect members of our community to be engaged in rigorous debate, discussion, and even disagreement. At times this may challenge you and even cause discomfort.
Our commitment to academic freedom means that we do not support so-called "trigger warnings," we do not cancel invited speakers because their topics might prove controversial, and we do not condone the creation of intellectual "safe spaces" where individuals can retreat from ideas and perspectives at odds with their own.
Fostering the free exchange of ideas reinforces a related University priority -- building a campus that welcomes people of all backgrounds. Diversity of opinion and background is a fundamental strength of our community. The members of our community must have the freedom to espouse and explore a wide range of ideas.
(Note that the University has clarified that this does not ban the use of trigger warnings or setting up safe spaces.) The letter has received national attention and generated controversy. Professors from the school and from different schools across the country, and the Foundation for Individual Rights in Education (FIRE), among others, rightly commend the university on its stance. FIRE notes that it "hopes that students, faculty, and administrators nationwide take a cue from UC and recommit to freedom of speech on their own campuses."
The letter follows a report generated by a specially-organized university group on freedom of expression.
Robert J. Zimmer, President of the University of Chicago, followed the letter with an op-ed in the Wall Street Journal, "Free Speech Is the Basis of a True Education." After discussing the intellectual skills students need for successful lives, including recognizing cultural differences, identifying complexity, and engaging in critical thinking about evidence, Zimmer states:
One word summarizes the process by which universities impart these skills: questioning. Productive and informed questioning involves challenging assumptions, arguments and conclusions. It calls for multiple and diverse perspectives and listening to the views of others. It requires understanding the power and limitations of arguments. More fundamentally, the process of questioning demands an ability to rethink one's own assumptions, often the most difficult task of all.
Essential to this process is an environment that promotes free expression and the open exchange of ideas, ensuring that difficult questions are asked and that diverse and challenging perspectives are considered. This underscores the importance of diversity among students, faculty and visitors--diversity of background, belief and experience. Without this, students' experience becomes a weak imitation of a true education, and the value of that education is seriously diminished.
One could not ask for a more thorough endorsement of free speech in universities. The concept of freedom of expression is crucial for many areas, not least in debate over Darwinism. Although he is almost certainly referencing it historically, note Zimmer's mention of evolution:
... Some assert that universities should be refuges from intellectual discomfort and that their own discomfort with conflicting and challenging views should override the value of free and open discourse.
We have seen efforts to suppress discussion of Charles Darwin's work, to insist upon particular political perspectives during the McCarthy era, to impose exclusionary acts of racial and religious discrimination, and to demand compliance with various forms of "moral" behavior.
The silencing being advocated today is equally problematic. Every attempt to legitimize silencing creates justification for others to restrain speech that they do not like in the future. [Emphasis added.]
Wow. Today the situation is reversed: those who question Darwin's work face discrimination. But the University of Chicago's position, at least in principle, would support free debate about neo-Darwinism and intelligent design, along with all other issues.
If only intelligent design proponents routinely faced this perspective. Perhaps Eric Hedin, physicist at Ball State University, would still be teaching his interdisciplinary honors course, "Boundaries of Science," which included some material on intelligent design. Perhaps the Michael Polanyi Center at Baylor University would still exist, with Dembski at its head.
Zimmer proclaims that violations of liberty pave the way for future restrictions. And professor Geoffrey Stone, chair of UC's Committee on Freedom of Expression, in an article quoted by FIRE, notes that academic freedom is key because first, "bitter experience has taught that even the ideas we hold to be most certain often turn out to be wrong," second, silencing some speech leads to more silencing, and third:
[A] central precept of free expression is the possibility of a chilling effect.... The potential costs of speaking courageously, of taking controversial positions, of taking risks, is greater than ever. Indeed, according to a recent survey, about half of American college students now say that it is unsafe for them to express unpopular views. Many faculty members clearly share that sentiment.
Stone's points hits home: intolerance of dissent from Darwinism has sparked all three of these issues.
Even though UC's position does not address intelligent design specifically, any step towards academic freedom on campus is beneficial. Freedom of speech staves off a downward spiral of viewpoint discrimination, allowing new (and sometimes more accurate) ideas to come forward.
After all, as Zimmer noted:
Universities cannot be viewed as a sanctuary for comfort but rather as a crucible for confronting ideas and thereby learning to make informed judgments in complex environments. Having one's assumptions challenged and experiencing the discomfort that sometimes accompanies this process are intrinsic parts of an excellent education. Only then will students develop the skills necessary to build their own futures and contribute to society.
It's high time for universities to extend protections to those who question neo-Darwinism. Perhaps Chicago's ringing endorsement of academic freedom will open more doors for evolution skeptics. We commend Robert Zimmer, John Ellison, and UC's Committee on Freedom of Expression for their courage.
Sarah Chaffee
Attempts to limit free speech on college campuses are many -- for example, at Yale, students berated professor Nicholas Christakis after he suggested that the school shouldn't regulate Halloween costumes that were not culturally sensitive.
Someone finally decided to stand up and defend freedom of speech as a defining principle of education. This summer, the University of Chicago's Dean of Students, John Ellison, sent a letter to all incoming freshman, stating:
Once here you will discover that one of the University of Chicago's defining characteristics is our commitment to freedom of inquiry and expression. This is captured in the University's faculty report on freedom of expression. Members of our community are encouraged to speak, write, listen, challenge, and learn, without fear of censorship. Civility and mutual respect are vital to all of us, and freedom of expression does not mean the freedom to harass or threaten others. You will find that we expect members of our community to be engaged in rigorous debate, discussion, and even disagreement. At times this may challenge you and even cause discomfort.
Our commitment to academic freedom means that we do not support so-called "trigger warnings," we do not cancel invited speakers because their topics might prove controversial, and we do not condone the creation of intellectual "safe spaces" where individuals can retreat from ideas and perspectives at odds with their own.
Fostering the free exchange of ideas reinforces a related University priority -- building a campus that welcomes people of all backgrounds. Diversity of opinion and background is a fundamental strength of our community. The members of our community must have the freedom to espouse and explore a wide range of ideas.
(Note that the University has clarified that this does not ban the use of trigger warnings or setting up safe spaces.) The letter has received national attention and generated controversy. Professors from the school and from different schools across the country, and the Foundation for Individual Rights in Education (FIRE), among others, rightly commend the university on its stance. FIRE notes that it "hopes that students, faculty, and administrators nationwide take a cue from UC and recommit to freedom of speech on their own campuses."
The letter follows a report generated by a specially-organized university group on freedom of expression.
Robert J. Zimmer, President of the University of Chicago, followed the letter with an op-ed in the Wall Street Journal, "Free Speech Is the Basis of a True Education." After discussing the intellectual skills students need for successful lives, including recognizing cultural differences, identifying complexity, and engaging in critical thinking about evidence, Zimmer states:
One word summarizes the process by which universities impart these skills: questioning. Productive and informed questioning involves challenging assumptions, arguments and conclusions. It calls for multiple and diverse perspectives and listening to the views of others. It requires understanding the power and limitations of arguments. More fundamentally, the process of questioning demands an ability to rethink one's own assumptions, often the most difficult task of all.
Essential to this process is an environment that promotes free expression and the open exchange of ideas, ensuring that difficult questions are asked and that diverse and challenging perspectives are considered. This underscores the importance of diversity among students, faculty and visitors--diversity of background, belief and experience. Without this, students' experience becomes a weak imitation of a true education, and the value of that education is seriously diminished.
One could not ask for a more thorough endorsement of free speech in universities. The concept of freedom of expression is crucial for many areas, not least in debate over Darwinism. Although he is almost certainly referencing it historically, note Zimmer's mention of evolution:
... Some assert that universities should be refuges from intellectual discomfort and that their own discomfort with conflicting and challenging views should override the value of free and open discourse.
We have seen efforts to suppress discussion of Charles Darwin's work, to insist upon particular political perspectives during the McCarthy era, to impose exclusionary acts of racial and religious discrimination, and to demand compliance with various forms of "moral" behavior.
The silencing being advocated today is equally problematic. Every attempt to legitimize silencing creates justification for others to restrain speech that they do not like in the future. [Emphasis added.]
Wow. Today the situation is reversed: those who question Darwin's work face discrimination. But the University of Chicago's position, at least in principle, would support free debate about neo-Darwinism and intelligent design, along with all other issues.
If only intelligent design proponents routinely faced this perspective. Perhaps Eric Hedin, physicist at Ball State University, would still be teaching his interdisciplinary honors course, "Boundaries of Science," which included some material on intelligent design. Perhaps the Michael Polanyi Center at Baylor University would still exist, with Dembski at its head.
Zimmer proclaims that violations of liberty pave the way for future restrictions. And professor Geoffrey Stone, chair of UC's Committee on Freedom of Expression, in an article quoted by FIRE, notes that academic freedom is key because first, "bitter experience has taught that even the ideas we hold to be most certain often turn out to be wrong," second, silencing some speech leads to more silencing, and third:
[A] central precept of free expression is the possibility of a chilling effect.... The potential costs of speaking courageously, of taking controversial positions, of taking risks, is greater than ever. Indeed, according to a recent survey, about half of American college students now say that it is unsafe for them to express unpopular views. Many faculty members clearly share that sentiment.
Stone's points hits home: intolerance of dissent from Darwinism has sparked all three of these issues.
Even though UC's position does not address intelligent design specifically, any step towards academic freedom on campus is beneficial. Freedom of speech staves off a downward spiral of viewpoint discrimination, allowing new (and sometimes more accurate) ideas to come forward.
After all, as Zimmer noted:
Universities cannot be viewed as a sanctuary for comfort but rather as a crucible for confronting ideas and thereby learning to make informed judgments in complex environments. Having one's assumptions challenged and experiencing the discomfort that sometimes accompanies this process are intrinsic parts of an excellent education. Only then will students develop the skills necessary to build their own futures and contribute to society.
It's high time for universities to extend protections to those who question neo-Darwinism. Perhaps Chicago's ringing endorsement of academic freedom will open more doors for evolution skeptics. We commend Robert Zimmer, John Ellison, and UC's Committee on Freedom of Expression for their courage.
Why Dawinism continues to go to seed.
How a Dry Seed Can Live a Thousand Years
Evolution News & Views
Maybe you have some in your garage: old seed packets that never made it into your gardening project years ago. Would they sprout if you planted them now? It's likely some would. Seeds can last for decades, sometimes centuries. In 2005, a date palm seed that survived dry conditions at Masada for 2,000 years germinated and remains on display in Israel, nicknamed Methuselah. The oldest carbon-dated seeds that have grown into viable plants are flowers that were buried under Siberian permafrost for 32,000 years, according to National Geographic.
What does it take to keep a seed viable for many years of slumber? At a basic level, we can envision some requirements. The seed must be able to shut down all non-critical operations. It must protect its vital parts, like its genetic information. And it must remain watchful for conditions that would allow it to wake up and carry out its growth program. The details, however, are truly astonishing. Some of them are described in an open-access paper in the Proceedings of the National Academy of Sciences, "Regulatory network analysis reveals novel regulators of seed desiccation tolerance in Arabidopsis thaliana." Seven geneticists in Mexico looked into this "remarkable" operation:
Desiccation tolerance (DT) is a remarkable process that allows seeds in the dry state to remain viable for long periods of time that in some instances exceed 1,000 y. It has been postulated that seed DT evolved by rewiring the regulatory and signaling networks that controlled vegetative DT, which itself emerged as a crucial adaptive trait of early land plants. Understanding the networks that regulate seed desiccation tolerance in model plant systems would provide the tools to understand an evolutionary process that played a crucial role in the diversification of flowering plants. In this work, we used an integrated approach that included genomics, bioinformatics, metabolomics, and molecular genetics to identify and validate molecular networks that control the acquisition of DT in Arabidopsis seeds. [Emphasis added.]
For now, we won't quibble about the evolution lingo, knowing that it's par for the course in journals these days (but maybe not for long, Doug Axe speculates in Chapter 12 of his new book Undeniable: How Biology Confirms Our Intuition That Life Is Designed). What's important to notice are the evidences of functional coherence that he shows are the hallmarks of invention, especially when arranged in a hierarchical manner for a high-level function. Here, the paper dazzles us with glimpses at astonishing complexity. "DT organisms orchestrate a complex number of responses to protect cellular structures and prevent damage to proteins and nucleic acids," they say in the introduction. Lest we overwhelm you with detail, let's get just a taste of what goes on in the plant preparing its seeds for long periods of dormancy:
As predicted, desiccation-intolerant (DI)-specific down-regulated genes were enriched (FDR < 0.05) in the following Gene Ontology (GO) categories: molecular function: oxidoreductase activity and nutrient reservoir; and biological process: lipid and carbohydrate biosynthesis, seed development, and ABA and stress responses such as water, oxidation, and temperature... A more detailed analysis of the same set of genes ... showed enrichment in processes such as abiotic stress, LEA protein synthesis, and metabolic pathways including raffinose, stachyose, and trehalose biosynthesis....
Enough said? We'll stick to layman terms from now on. Clearly, preparation for DT is no simple matter! To find out what genes and transcription factors are involved, they compared wild-type plants with mutants unable to prepare for desiccation. In their words, "The finding that genes that are not activated in desiccation-intolerant mutants during seed maturation belong to water stress and cell protection mechanisms confirmed that desiccation-intolerant mutants fail to activate mechanisms required to acquire DT in the seed."
The genes that prepare a seed for dryness cooperate in regulatory networks. Stephen Meyer shows in Chapter 13 of Darwin's Doubt that one does not just tweak developmental gene regulatory networks (dGRNs) willy-nilly and expect to get a new function (that was Charles Marshall's story for the Cambrian explosion, remember? See Debating Darwin's Doubt, Chapters 10-11). For one thing, GRNs "do not tolerate random perturbations to their basic control logic," all available evidence shows (p. 130). For another, it would require just as much information to rewire a GRN for a novel function as it would to evolve new genes, so that's no solution at all (p. 134). But enough about origins; let's get back to the mechanics of DT.
You can well imagine conditions in the soil that would attack a seed's genetic information. When the plant is growing, numerous processes survey and repair DNA. But what happens when the seed goes to sleep? Counter-intuitively, water can be one of the night stalkers.
One of the most intriguing questions about how seeds in the desiccated state can remain viable for periods of time that can exceed centuries is particularly how the integrity of DNA is preserved to prevent permanent damage making the seed unviable. Three types of DNA damage under physiological conditions have been reported: hydrolysis of the N-glycosyl bond, hydrolytic deamination of cytosine to form uracil, and DNA damage by oxidation. The first two types of DNA damage are catalyzed by water, and therefore the last layers of water that interact with DNA need to be removed or decreased to prevent damage, and the third is mediated mainly by reactive oxygen species (ROS).
The plant uses a clever trick to protect its DNA from attack by water. It replaces water molecules with sugars. Hydroxyl groups (OH) of certain sugars can provide the necessary bonds to stabilize proteins, DNA and membranes from these kinds of damage. The team found that biosynthesis of three particular sugars is up-regulated during the final stages of seed preparation, in agreement with this mechanism. They also found genes were increased for five kinds of enzymes involved in protection from reactive oxygen species (ROS).
Therefore, accumulation of antioxidant components during the late maturation stage contributes to controlling their storage potential, and helps to prevent damage from accumulated ROS during seed maturation. Accumulation of RFOs [the raffinose family of oligosaccharides, one of the types of protective sugars] and activation of mechanisms that prevent damage by ROS allow maximum metabolism reduction to decrease the production of toxic compounds and to prevent membrane, DNA, RNA, and protein damage.
All these genes are accompanied by transcription factors that switch them on and off. The authors speak about not only regulatory networks, but regulatory subnetworks. One, for instance, downregulates proteins involved in germination, to prevent early sprouting. Another is involved in stress tolerance. They identified at least four such subnetworks. Some of the subnetworks themselves involve hundreds of genes!
The researchers spoke mainly about preparation for desiccation. They didn't get into other equally fascinating questions: What activities continue during the decades or centuries of slumber? (We know from our own sleep that our hearts must still beat, we must continue breathing, and much more.) How are genes repaired by cosmic ray damage and other contingencies? And what re-activates growth processes when conditions are right for sprouting? How does a blind seed, buried in the dark soil, know when it's time to wake up? What are the first steps it takes to germinate?
This brief glimpse at desiccation tolerance in one model plant ensures is that the answers to those questions will likely be just as complicated -- and fascinating. Like so many things in the biosphere, the apparently simple process of a seed preparing for sleep is anything but simple. Evolution stories often trade in generalities. Intelligent design evidences are best seen in the details. Like Doug Axe says, biology with a design perspective becomes like a great geocaching game. "What makes finding a well-conceived geocache so delightful," he explains, "is not just the sense of having found something that was hard to find -- though that's part of it -- but the sense of having found something that was meant to be found and cleverly made hard to find" (Undeniable, p. 248). It appears we just found a good prize right under our feet.
Evolution News & Views
Maybe you have some in your garage: old seed packets that never made it into your gardening project years ago. Would they sprout if you planted them now? It's likely some would. Seeds can last for decades, sometimes centuries. In 2005, a date palm seed that survived dry conditions at Masada for 2,000 years germinated and remains on display in Israel, nicknamed Methuselah. The oldest carbon-dated seeds that have grown into viable plants are flowers that were buried under Siberian permafrost for 32,000 years, according to National Geographic.
What does it take to keep a seed viable for many years of slumber? At a basic level, we can envision some requirements. The seed must be able to shut down all non-critical operations. It must protect its vital parts, like its genetic information. And it must remain watchful for conditions that would allow it to wake up and carry out its growth program. The details, however, are truly astonishing. Some of them are described in an open-access paper in the Proceedings of the National Academy of Sciences, "Regulatory network analysis reveals novel regulators of seed desiccation tolerance in Arabidopsis thaliana." Seven geneticists in Mexico looked into this "remarkable" operation:
Desiccation tolerance (DT) is a remarkable process that allows seeds in the dry state to remain viable for long periods of time that in some instances exceed 1,000 y. It has been postulated that seed DT evolved by rewiring the regulatory and signaling networks that controlled vegetative DT, which itself emerged as a crucial adaptive trait of early land plants. Understanding the networks that regulate seed desiccation tolerance in model plant systems would provide the tools to understand an evolutionary process that played a crucial role in the diversification of flowering plants. In this work, we used an integrated approach that included genomics, bioinformatics, metabolomics, and molecular genetics to identify and validate molecular networks that control the acquisition of DT in Arabidopsis seeds. [Emphasis added.]
For now, we won't quibble about the evolution lingo, knowing that it's par for the course in journals these days (but maybe not for long, Doug Axe speculates in Chapter 12 of his new book Undeniable: How Biology Confirms Our Intuition That Life Is Designed). What's important to notice are the evidences of functional coherence that he shows are the hallmarks of invention, especially when arranged in a hierarchical manner for a high-level function. Here, the paper dazzles us with glimpses at astonishing complexity. "DT organisms orchestrate a complex number of responses to protect cellular structures and prevent damage to proteins and nucleic acids," they say in the introduction. Lest we overwhelm you with detail, let's get just a taste of what goes on in the plant preparing its seeds for long periods of dormancy:
As predicted, desiccation-intolerant (DI)-specific down-regulated genes were enriched (FDR < 0.05) in the following Gene Ontology (GO) categories: molecular function: oxidoreductase activity and nutrient reservoir; and biological process: lipid and carbohydrate biosynthesis, seed development, and ABA and stress responses such as water, oxidation, and temperature... A more detailed analysis of the same set of genes ... showed enrichment in processes such as abiotic stress, LEA protein synthesis, and metabolic pathways including raffinose, stachyose, and trehalose biosynthesis....
Enough said? We'll stick to layman terms from now on. Clearly, preparation for DT is no simple matter! To find out what genes and transcription factors are involved, they compared wild-type plants with mutants unable to prepare for desiccation. In their words, "The finding that genes that are not activated in desiccation-intolerant mutants during seed maturation belong to water stress and cell protection mechanisms confirmed that desiccation-intolerant mutants fail to activate mechanisms required to acquire DT in the seed."
The genes that prepare a seed for dryness cooperate in regulatory networks. Stephen Meyer shows in Chapter 13 of Darwin's Doubt that one does not just tweak developmental gene regulatory networks (dGRNs) willy-nilly and expect to get a new function (that was Charles Marshall's story for the Cambrian explosion, remember? See Debating Darwin's Doubt, Chapters 10-11). For one thing, GRNs "do not tolerate random perturbations to their basic control logic," all available evidence shows (p. 130). For another, it would require just as much information to rewire a GRN for a novel function as it would to evolve new genes, so that's no solution at all (p. 134). But enough about origins; let's get back to the mechanics of DT.
You can well imagine conditions in the soil that would attack a seed's genetic information. When the plant is growing, numerous processes survey and repair DNA. But what happens when the seed goes to sleep? Counter-intuitively, water can be one of the night stalkers.
One of the most intriguing questions about how seeds in the desiccated state can remain viable for periods of time that can exceed centuries is particularly how the integrity of DNA is preserved to prevent permanent damage making the seed unviable. Three types of DNA damage under physiological conditions have been reported: hydrolysis of the N-glycosyl bond, hydrolytic deamination of cytosine to form uracil, and DNA damage by oxidation. The first two types of DNA damage are catalyzed by water, and therefore the last layers of water that interact with DNA need to be removed or decreased to prevent damage, and the third is mediated mainly by reactive oxygen species (ROS).
The plant uses a clever trick to protect its DNA from attack by water. It replaces water molecules with sugars. Hydroxyl groups (OH) of certain sugars can provide the necessary bonds to stabilize proteins, DNA and membranes from these kinds of damage. The team found that biosynthesis of three particular sugars is up-regulated during the final stages of seed preparation, in agreement with this mechanism. They also found genes were increased for five kinds of enzymes involved in protection from reactive oxygen species (ROS).
Therefore, accumulation of antioxidant components during the late maturation stage contributes to controlling their storage potential, and helps to prevent damage from accumulated ROS during seed maturation. Accumulation of RFOs [the raffinose family of oligosaccharides, one of the types of protective sugars] and activation of mechanisms that prevent damage by ROS allow maximum metabolism reduction to decrease the production of toxic compounds and to prevent membrane, DNA, RNA, and protein damage.
All these genes are accompanied by transcription factors that switch them on and off. The authors speak about not only regulatory networks, but regulatory subnetworks. One, for instance, downregulates proteins involved in germination, to prevent early sprouting. Another is involved in stress tolerance. They identified at least four such subnetworks. Some of the subnetworks themselves involve hundreds of genes!
The researchers spoke mainly about preparation for desiccation. They didn't get into other equally fascinating questions: What activities continue during the decades or centuries of slumber? (We know from our own sleep that our hearts must still beat, we must continue breathing, and much more.) How are genes repaired by cosmic ray damage and other contingencies? And what re-activates growth processes when conditions are right for sprouting? How does a blind seed, buried in the dark soil, know when it's time to wake up? What are the first steps it takes to germinate?
This brief glimpse at desiccation tolerance in one model plant ensures is that the answers to those questions will likely be just as complicated -- and fascinating. Like so many things in the biosphere, the apparently simple process of a seed preparing for sleep is anything but simple. Evolution stories often trade in generalities. Intelligent design evidences are best seen in the details. Like Doug Axe says, biology with a design perspective becomes like a great geocaching game. "What makes finding a well-conceived geocache so delightful," he explains, "is not just the sense of having found something that was hard to find -- though that's part of it -- but the sense of having found something that was meant to be found and cleverly made hard to find" (Undeniable, p. 248). It appears we just found a good prize right under our feet.
Sunday, 28 August 2016
Saturday, 27 August 2016
John20:31 demystified.
John 20:31 - John sums up his Gospel
The conclusion of John was not the blockbuster news that Jesus was God. It wasn't that Jesus was equal to God in any sense.
John 20:30: "Jesus did many other miraculous signs which are not recorded in this book. 31: But these are written that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name. - New International Version Study Bible (NIVSB), Zondervan, 1985.
And the footnote for John 20:31 in the NIVSB says: “…. This whole Gospel is written to show the truth of Jesus’ Messiahship and to present him as the Son of God”.
But ‘Messiah’ and ‘son of God’ were never understood to mean God Himself!
In the language of the OT ... rulers and judges, as deputies of the heavenly King, could “be given the honorific title ‘god’ ... or be called ‘son of God’.” - footnote for Ps. 82:1, NIVSB.
Today’s Dictionary of the Bible (trinitarian), p. 591, Bethany House, 1982: “In Job 1:6; 38:7 this name [‘sons of God’] is applied to the angels.”
An Encyclopedia of Religion, Ferm, 1945 ed., p. 726, “Son of God: Hebrew religion was strictly monotheistic, and the term ‘Son of God’, as found in the OT, must not be understood in any literal sense. It has its origin in the Semitic idiom which expresses any intimate relation as one of sonship. As royal ministers are sons of the king, so the angels are sons of God, and this name is likewise given to judges and sovereigns, ruling in God’s name.”
So we see that John’s whole Gospel was to show who was the Messiah! If he had believed in the trinity (or ‘Jesus is God’), he would certainly have made a great, unmistakably clear declaration of it!! But he did not!
This is of great importance since none of the earlier Gospels made any clear statement showing Jesus to be God! If any such thing were believed by the Apostles and Bible writers, it would have to be found here in John’s conclusion!
Posted by Elijah Daniels
The conclusion of John was not the blockbuster news that Jesus was God. It wasn't that Jesus was equal to God in any sense.
John 20:30: "Jesus did many other miraculous signs which are not recorded in this book. 31: But these are written that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name. - New International Version Study Bible (NIVSB), Zondervan, 1985.
And the footnote for John 20:31 in the NIVSB says: “…. This whole Gospel is written to show the truth of Jesus’ Messiahship and to present him as the Son of God”.
But ‘Messiah’ and ‘son of God’ were never understood to mean God Himself!
In the language of the OT ... rulers and judges, as deputies of the heavenly King, could “be given the honorific title ‘god’ ... or be called ‘son of God’.” - footnote for Ps. 82:1, NIVSB.
Today’s Dictionary of the Bible (trinitarian), p. 591, Bethany House, 1982: “In Job 1:6; 38:7 this name [‘sons of God’] is applied to the angels.”
An Encyclopedia of Religion, Ferm, 1945 ed., p. 726, “Son of God: Hebrew religion was strictly monotheistic, and the term ‘Son of God’, as found in the OT, must not be understood in any literal sense. It has its origin in the Semitic idiom which expresses any intimate relation as one of sonship. As royal ministers are sons of the king, so the angels are sons of God, and this name is likewise given to judges and sovereigns, ruling in God’s name.”
So we see that John’s whole Gospel was to show who was the Messiah! If he had believed in the trinity (or ‘Jesus is God’), he would certainly have made a great, unmistakably clear declaration of it!! But he did not!
This is of great importance since none of the earlier Gospels made any clear statement showing Jesus to be God! If any such thing were believed by the Apostles and Bible writers, it would have to be found here in John’s conclusion!
Posted by Elijah Daniels
Moving towards the light.
Why Have Jehovah’s Witnesses Changed Some of Their Beliefs?
We have always used the Bible as the sole authority for our beliefs, so we have adjusted our beliefs as our understanding of the Scriptures has been clarified. *
Such changes are in harmony with the Bible principle stated at Proverbs 4:18: “The path of the righteous is like the bright morning light that grows brighter and brighter until full daylight.” Just as the rising sun reveals details of a landscape gradually, God grants an understanding of divine truth progressively, in his due time. (1 Peter 1:10-12) As the Bible foretold, he has accelerated this process during “the time of the end.”—Daniel 12:4.
These adjustments in our understanding should neither surprise nor disturb us. Ancient worshippers of God also had mistaken ideas and expectations and needed to adjust their viewpoint.
Moses offered himself as a deliverer for the nation of Israel 40 years ahead of God’s timetable.—Acts 7:23-25, 30, 35.
The apostles failed to understand the prophecy that foretold the Messiah’s death and resurrection.—Isaiah 53:8-12; Matthew 16:21-23.
Some early Christians had wrong ideas about the timing of “the day of Jehovah.”—2 Thessalonians 2:1, 2.
God later corrected their misunderstandings, and we pray that he will continue doing the same for us.—James 1:5.
We have always used the Bible as the sole authority for our beliefs, so we have adjusted our beliefs as our understanding of the Scriptures has been clarified. *
Such changes are in harmony with the Bible principle stated at Proverbs 4:18: “The path of the righteous is like the bright morning light that grows brighter and brighter until full daylight.” Just as the rising sun reveals details of a landscape gradually, God grants an understanding of divine truth progressively, in his due time. (1 Peter 1:10-12) As the Bible foretold, he has accelerated this process during “the time of the end.”—Daniel 12:4.
These adjustments in our understanding should neither surprise nor disturb us. Ancient worshippers of God also had mistaken ideas and expectations and needed to adjust their viewpoint.
Moses offered himself as a deliverer for the nation of Israel 40 years ahead of God’s timetable.—Acts 7:23-25, 30, 35.
The apostles failed to understand the prophecy that foretold the Messiah’s death and resurrection.—Isaiah 53:8-12; Matthew 16:21-23.
Some early Christians had wrong ideas about the timing of “the day of Jehovah.”—2 Thessalonians 2:1, 2.
God later corrected their misunderstandings, and we pray that he will continue doing the same for us.—James 1:5.
The quest to deprivilege our home planet rolls on.
Rob Sheldon on the new Earth-like planet
Posted by News under Exoplanets
I wouldn’t get my hopes up. Years ago, people didn’t put this type of planet in the “Goldilocks zone”. That’s because of tidal locking.
Very briefly, the tidal force is the difference between gravity on one side of the planet and gravity on the other.
Think of a gravity well as shaped like a funnel. If the planet is really close to the star’s gravity well, then the slope of the funnel is steep, and one side of the planet is lower in the funnel than the other side. This means that there’s a “stretching” force on the planet corresponding to this gravity gradient, which we call “the tidal force”. You and I don’t experience it much, because the difference between 93million miles (distance to sun) and 93 million miles + 5′, is in the parts per trillion. But for this planet that is orbiting a dull red star closer than Mercury is to our Sun, so close that a year is 11 days, this difference starts to get substantial.
So what happens? The planet stretches. Then one side is even closer than before and that side wants to always face the sun. Then like the Moon, it adjusts its rotation so that this side faces the sun 24/7, it is “tidally locked”.
If one side of the planet always faces the sun, it gets hot, while the backside never faces the sun and gets cold. The hot side boils water, the cold side freezes it. All the water migrates over to the freezer, and gets locked in ice. There’s little chance of ever finding liquid water on such a planet. If there is a region where water is liquid, the “Goldilocks zone”, then it occupies a narrow strip where the sun is only half-way above the horizon. But for most of my lifetime, it was expected that even liquid water will eventually evaporate, so that the Goldilocks zone dries out. Then there is no liquid water left on such a planet.
So why are we even considering such a planet “Earth-like”?
Mostly desperation. A few papers suggest that if there is an atmosphere, then convection can bring warm air over to the glaciers on the backside and share the heat. Of course, Mercury and the Moon don’t have much of an atmosphere, mostly because tidally-locking tends to remove it. But hope springs eternal. Especially if it brings cash.
Jut for now, avoid the land rush boom. 😉
Posted by News under Exoplanets
I wouldn’t get my hopes up. Years ago, people didn’t put this type of planet in the “Goldilocks zone”. That’s because of tidal locking.
Very briefly, the tidal force is the difference between gravity on one side of the planet and gravity on the other.
Think of a gravity well as shaped like a funnel. If the planet is really close to the star’s gravity well, then the slope of the funnel is steep, and one side of the planet is lower in the funnel than the other side. This means that there’s a “stretching” force on the planet corresponding to this gravity gradient, which we call “the tidal force”. You and I don’t experience it much, because the difference between 93million miles (distance to sun) and 93 million miles + 5′, is in the parts per trillion. But for this planet that is orbiting a dull red star closer than Mercury is to our Sun, so close that a year is 11 days, this difference starts to get substantial.
So what happens? The planet stretches. Then one side is even closer than before and that side wants to always face the sun. Then like the Moon, it adjusts its rotation so that this side faces the sun 24/7, it is “tidally locked”.
If one side of the planet always faces the sun, it gets hot, while the backside never faces the sun and gets cold. The hot side boils water, the cold side freezes it. All the water migrates over to the freezer, and gets locked in ice. There’s little chance of ever finding liquid water on such a planet. If there is a region where water is liquid, the “Goldilocks zone”, then it occupies a narrow strip where the sun is only half-way above the horizon. But for most of my lifetime, it was expected that even liquid water will eventually evaporate, so that the Goldilocks zone dries out. Then there is no liquid water left on such a planet.
So why are we even considering such a planet “Earth-like”?
Mostly desperation. A few papers suggest that if there is an atmosphere, then convection can bring warm air over to the glaciers on the backside and share the heat. Of course, Mercury and the Moon don’t have much of an atmosphere, mostly because tidally-locking tends to remove it. But hope springs eternal. Especially if it brings cash.
Jut for now, avoid the land rush boom. 😉
Friday, 26 August 2016
Monday, 22 August 2016
Sunday, 21 August 2016
John8:58 demystfied.
John 8:58 - Did Jesus Really Say, "I AM"?
Many Bible versions render John 8:58 this way: "Jesus said to them, "Truly, truly, I say to you, before Abraham was, I am."
And Ex. 3:14 this way: "God said to Moses, "I AM WHO I AM." And he said, "Say this to the people of Israel, 'I AM has sent me to you.'"
(Because of this, Trinitarians often refer to this as 'proof' that Jesus is the Hebrew GOD of the Old Testament.)
But are the words "I am" supposed to be God's name? Even if it were so, would it make sense in John 8:58 for Jesus to say the equivalent of, "Most assuredly I say to you, before Abraham was...JEHOVAH?!?"
Looking at the context, the correct phrasing of this sentence should be "I was" instead of "I am" when used after the word "before." Also in verse 57, the question to which Jesus was replying had to do with age, not identity.
During the exchange with the Jews leading up to John 8:58, nowhere does Jesus claim to be God. And as we've already seen, the words "I am" at John 8:58 (including the blatant unwarranted use of capitalization) is not only inaccurate but nonsensical.
Several translations phrase John 8:58 the correct way by which Jesus was actually illustrating how long he has existed. One, for instance:
"Jesus answered, "The truth is, I EXISTED BEFORE ABRAHAM WAS EVEN BORN!" (NLT)
Besides that, numerous Trinitarian authorities even have to admit that "I am" in Ex. 3:14 is not even correct and should be rendered more like "I will Be" (the meaning of God's name rather than God's personal name itself...Jehovah):
Encyclopedia Britannica:
"The writer of Exodus 3:14-15 ... explains it [the meaning of God's name] by the phrase EHYEH asher EHYEH (Ex. iii., 14); this can be translated `I am that I am' or more exactly `I am wont to be that which I am wont to be' or `I will be that which I will be.'" - p. 995, 14th ed., v. 12.
Many Bible versions render John 8:58 this way: "Jesus said to them, "Truly, truly, I say to you, before Abraham was, I am."
And Ex. 3:14 this way: "God said to Moses, "I AM WHO I AM." And he said, "Say this to the people of Israel, 'I AM has sent me to you.'"
(Because of this, Trinitarians often refer to this as 'proof' that Jesus is the Hebrew GOD of the Old Testament.)
But are the words "I am" supposed to be God's name? Even if it were so, would it make sense in John 8:58 for Jesus to say the equivalent of, "Most assuredly I say to you, before Abraham was...JEHOVAH?!?"
Looking at the context, the correct phrasing of this sentence should be "I was" instead of "I am" when used after the word "before." Also in verse 57, the question to which Jesus was replying had to do with age, not identity.
During the exchange with the Jews leading up to John 8:58, nowhere does Jesus claim to be God. And as we've already seen, the words "I am" at John 8:58 (including the blatant unwarranted use of capitalization) is not only inaccurate but nonsensical.
Several translations phrase John 8:58 the correct way by which Jesus was actually illustrating how long he has existed. One, for instance:
"Jesus answered, "The truth is, I EXISTED BEFORE ABRAHAM WAS EVEN BORN!" (NLT)
Besides that, numerous Trinitarian authorities even have to admit that "I am" in Ex. 3:14 is not even correct and should be rendered more like "I will Be" (the meaning of God's name rather than God's personal name itself...Jehovah):
Encyclopedia Britannica:
"The writer of Exodus 3:14-15 ... explains it [the meaning of God's name] by the phrase EHYEH asher EHYEH (Ex. iii., 14); this can be translated `I am that I am' or more exactly `I am wont to be that which I am wont to be' or `I will be that which I will be.'" - p. 995, 14th ed., v. 12.
Saturday, 20 August 2016
Scarlet colored beast of revelation 17:The watchtower Society's commentary.
What Is the Scarlet-Colored Beast of Revelation Chapter 17?
Keys to identifying the scarlet-colored beast
A political entity. The scarlet-colored beast has “seven heads” that are said to represent “seven mountains” and “seven kings,” or ruling powers. (Revelation 17:9, 10) Mountains and beasts are used in the Bible as symbols of governments.—Jeremiah 51:24, 25; Daniel 2:44, 45; 7:17, 23.
A likeness of the worldwide political system. The scarlet-colored beast resembles the seven-headed beast of Revelation chapter 13, which represents the worldwide political system. Both beasts have seven heads, ten horns, and blasphemous names. (Revelation 13:1; 17:3) These similarities are too striking to be a coincidence. The scarlet-colored beast is an image, or likeness, of the worldwide political system.—Revelation 13:15.
Power from other rulerships. The scarlet-colored beast “springs from,” or owes its existence to, other ruling forces.—Revelation 17:11, 17.
Linked with religion. Babylon the Great, the world’s collective body of false religions, sits on the scarlet-colored beast, showing that the beast is influenced by religious groups.—Revelation 17:3-5.
Dishonors God. The beast is “full of blasphemous names.”—Revelation 17:3.
Temporarily inactive. The scarlet-colored beast would be in “the abyss,” * or inactive, for a time but would rise again.—Revelation 17:8.
Bible prophecy fulfilled
Consider how the United Nations and its predecessor, the League of Nations, have fulfilled the Bible’s prophecy of the scarlet-colored beast.
A political entity.:The United Nations supports the political system by upholding “the sovereign equality of all its Members.”
A likeness of the worldwide political system.:In 2011, the United Nations added its 193rd member state. Thus, it claims to represent the vast majority of nations and peoples in the world.
Power from other rulerships.:The United Nations owes its existence to its member nations and has only as much power and authority as they grant to it.
Linked with religion.:Both the League of Nations and the United Nations have consistently received the backing of the world’s religions.
Dishonors God. :The United Nations was established “to maintain international peace and security.” * While this goal might seem to be praiseworthy, the UN actually dishonors God by claiming to do what he has said only his Kingdom will accomplish.—Psalm 46:9; Daniel 2:44.
Temporarily inactive.:The League of Nations, which was formed shortly after World War I to maintain peace, was unable to prevent international aggression. It ceased to function when World War II began in 1939. In 1945, after World War II ended, the United Nations was formed. Its purposes, methods, and structure closely resemble those of the League of Nations.
Keys to identifying the scarlet-colored beast
A political entity. The scarlet-colored beast has “seven heads” that are said to represent “seven mountains” and “seven kings,” or ruling powers. (Revelation 17:9, 10) Mountains and beasts are used in the Bible as symbols of governments.—Jeremiah 51:24, 25; Daniel 2:44, 45; 7:17, 23.
A likeness of the worldwide political system. The scarlet-colored beast resembles the seven-headed beast of Revelation chapter 13, which represents the worldwide political system. Both beasts have seven heads, ten horns, and blasphemous names. (Revelation 13:1; 17:3) These similarities are too striking to be a coincidence. The scarlet-colored beast is an image, or likeness, of the worldwide political system.—Revelation 13:15.
Power from other rulerships. The scarlet-colored beast “springs from,” or owes its existence to, other ruling forces.—Revelation 17:11, 17.
Linked with religion. Babylon the Great, the world’s collective body of false religions, sits on the scarlet-colored beast, showing that the beast is influenced by religious groups.—Revelation 17:3-5.
Dishonors God. The beast is “full of blasphemous names.”—Revelation 17:3.
Temporarily inactive. The scarlet-colored beast would be in “the abyss,” * or inactive, for a time but would rise again.—Revelation 17:8.
Bible prophecy fulfilled
Consider how the United Nations and its predecessor, the League of Nations, have fulfilled the Bible’s prophecy of the scarlet-colored beast.
A political entity.:The United Nations supports the political system by upholding “the sovereign equality of all its Members.”
A likeness of the worldwide political system.:In 2011, the United Nations added its 193rd member state. Thus, it claims to represent the vast majority of nations and peoples in the world.
Power from other rulerships.:The United Nations owes its existence to its member nations and has only as much power and authority as they grant to it.
Linked with religion.:Both the League of Nations and the United Nations have consistently received the backing of the world’s religions.
Dishonors God. :The United Nations was established “to maintain international peace and security.” * While this goal might seem to be praiseworthy, the UN actually dishonors God by claiming to do what he has said only his Kingdom will accomplish.—Psalm 46:9; Daniel 2:44.
Temporarily inactive.:The League of Nations, which was formed shortly after World War I to maintain peace, was unable to prevent international aggression. It ceased to function when World War II began in 1939. In 1945, after World War II ended, the United Nations was formed. Its purposes, methods, and structure closely resemble those of the League of Nations.
The Watchtower Society's commentary on "Faith"
FAITH:
The word “faith” is translated from the Greek piʹstis, primarily conveying the thought of confidence, trust, firm persuasion. Depending on the context, the Greek word may also be understood to mean “faithfulness” or “fidelity.”—1Th 3:7; Tit 2:10.
The Scriptures tell us: “Faith is the assured expectation of things hoped for, the evident demonstration of realities though not beheld.” (Heb 11:1) “Assured expectation” translates the Greek word hy·poʹsta·sis. This term is common in ancient papyrus business documents. It conveys the idea of something that underlies visible conditions and guarantees a future possession. In view of this, Moulton and Milligan suggest the rendering: “Faith is the title deed of things hoped for.” (Vocabulary of the Greek Testament, 1963, p. 660) The Greek word eʹleg·khos, rendered “evident demonstration,” conveys the idea of bringing forth evidence that demonstrates something, particularly something contrary to what appears to be the case. Thereby this evidence makes clear what has not been discerned before and so refutes what has only appeared to be the case. “The evident demonstration,” or evidence for conviction, is so positive or powerful that faith is said to be it.
Faith is, therefore, the basis for hope and the evidence for conviction concerning unseen realities. The entire body of truths delivered by Jesus Christ and his inspired disciples constitutes the true Christian “faith.” (Joh 18:37; Ga 1:7-9; Ac 6:7; 1Ti 5:8) Christian faith is based on the complete Word of God, including the Hebrew Scriptures, to which Jesus and the writers of the Christian Greek Scriptures frequently referred in support of their statements.
Faith is based on concrete evidence. The visible creative works testify to the existence of an invisible Creator. (Ro 1:20) The actual occurrences taking place during the ministry and earthly life of Jesus Christ identify him as the Son of God. (Mt 27:54; see JESUS CHRIST.) God’s record of providing for his earthly creatures serves as a valid basis for believing that he will surely provide for his servants, and his record as a Giver and Restorer of life lends ample evidence to the credibility of the resurrection hope. (Mt 6:26, 30, 33; Ac 17:31; 1Co 15:3-8, 20, 21) Furthermore, the reliability of God’s Word and the accurate fulfillment of its prophecies instill confidence in the realization of all of His promises. (Jos 23:14) Thus, in these many ways, “faith follows the thing heard.”—Ro 10:17; compare Joh 4:7-30, 39-42; Ac 14:8-10.
So faith is not credulity. The person who may ridicule faith usually has faith himself in tried and trusted friends. The scientist has faith in the principles of his branch of science. He bases new experiments on past discoveries and looks for new discoveries on the basis of those things already established as true. Likewise, the farmer prepares his soil and sows the seed, expecting, as in previous years, that the seed will sprout and that the plants will grow as they receive the needed moisture and sunshine. Therefore faith in the stability of the natural laws governing the universe actually constitutes a foundation for man’s plans and activities. Such stability is alluded to by the wise writer of Ecclesiastes: “The sun also has flashed forth, and the sun has set, and it is coming panting to its place where it is going to flash forth. The wind is going to the south, and it is circling around to the north. Round and round it is continually circling, and right back to its circlings the wind is returning. All the winter torrents are going forth to the sea, yet the sea itself is not full. To the place where the winter torrents are going forth, there they are returning so as to go forth.”—Ec 1:5-7.
In the Hebrew Scriptures, the word ʼa·manʹ and other words closely related convey the sense of trustworthiness, faithfulness, steadiness, steadfastness, being firmly established, long-lasting. (Ex 17:12; De 28:59; 1Sa 2:35; 2Sa 7:16; Ps 37:3) One related noun (ʼemethʹ) usually denotes “truth,” but also “faithfulness” or “trustworthiness.” (2Ch 15:3, ftn; 2Sa 15:20; compare Ne 7:2, ftn.) The familiar term “Amen” (Heb., ʼa·menʹ) also comes from ʼa·manʹ.—See AMEN.
Ancient Examples of Faith. Each one of the “so great a cloud of witnesses” mentioned by Paul (Heb 12:1) had a valid basis for faith. For example, Abel certainly knew about God’s promise concerning a “seed” that would bruise “the serpent” in the head. And he saw tangible evidences of the fulfillment of the sentence Jehovah pronounced upon his parents in Eden. Outside Eden, Adam and his family ate bread in the sweat of their face because the ground was cursed and, therefore, produced thorns and thistles. Likely Abel observed that Eve’s craving was for her husband and that Adam dominated his wife. Undoubtedly his mother commented about the pain attending her pregnancy. Then, too, the entrance to the garden of Eden was being guarded by cherubs and the flaming blade of a sword. (Ge 3:14-19, 24) All of this constituted an “evident demonstration,” giving Abel the assurance that deliverance would come through the ‘seed of promise.’ Therefore, prompted by faith, he “offered God a sacrifice,” one that proved to be of greater worth than that of Cain.—Heb 11:1, 4.
Abraham had a firm basis for faith in a resurrection, for he and Sarah had experienced the miraculous restoration of their reproductive powers, which was, in a sense, comparable to a resurrection, allowing Abraham’s family line to continue through Sarah. Isaac was born as the result of this miracle. When told to offer up Isaac, Abraham had faith that God would resurrect his son. He based such faith on God’s promise: “It is by means of Isaac that what will be called your seed will be.”—Ge 21:12; Heb 11:11, 12, 17-19.
Evidence for genuine conviction was also involved in the case of those who came to or who were brought to Jesus to be healed. Even if not eyewitnesses personally, they at least had heard about Jesus’ powerful works. Then, on the basis of what they saw or heard, they concluded that Jesus could heal them also. Moreover, they were acquainted with God’s Word and thus were familiar with the miracles performed by the prophets in times past. Upon hearing Jesus, some concluded that he was “The Prophet,” and others that he was “the Christ.” In view of this, it was most fitting for Jesus on occasion to say to those who were healed, “Your faith has made you well.” Had those persons not exercised faith in Jesus, they would not have approached him in the first place and, therefore, would not have received healing for themselves.—Joh 7:40, 41; Mt 9:22; Lu 17:19.
Likewise, the great faith of the army officer who entreated Jesus in behalf of his manservant rested on evidence, on the basis of which he concluded that Jesus’ merely ‘saying the word’ would result in the healing of his manservant. (Mt 8:5-10, 13) However, we note that Jesus healed all who came to him, not requiring faith greater or less according to their disease, nor failing to heal any of these with the excuse that he could not do it because their faith was not strong enough. Jesus performed these healings as a witness, to establish faith. In his home territory, where much unfaithfulness was expressed, he chose not to perform many powerful works, not because of inability, but because the people refused to listen and were unworthy.—Mt 13:58.
Christian Faith. To be acceptable to God, it is now necessary for one to exercise faith in Jesus Christ, and this makes possible a righteous standing with God. (Ga 2:16) Those lacking such faith are rejected by Jehovah.—Joh 3:36; compare Heb 11:6.
Faith is not the possession of all persons, as it is a fruit of God’s spirit. (2Th 3:2; Ga 5:22) And a Christian’s faith is not static, but it grows. (2Th 1:3) Hence, the request of Jesus’ disciples, “Give us more faith,” was very appropriate, and he did provide them the foundation for increased faith. He supplied them with greater evidence and understanding on which to base their faith.—Lu 17:5.
The entire life course of a Christian is actually governed by faith, enabling him to overcome mountainlike obstacles that would hinder his service to God. (2Co 5:7; Mt 21:21, 22) Additionally, there must be works consistent with and in display of faith, but works of the Mosaic Law are not required. (Jas 2:21-26; Ro 3:20) Trials can strengthen faith. Faith serves as a protective shield in the Christian’s spiritual warfare, helping him to overcome the Devil and be a conqueror of the world.—1Pe 1:6, 7; Eph 6:16; 1Pe 5:9; 1Jo 5:4.
But faith cannot be taken for granted, because lack of faith is ‘the sin that so easily entangles one.’ To maintain a firm faith requires putting up a hard fight for it, resisting men who could plunge one into immorality, combating the works of the flesh, avoiding the snare of materialism, shunning faith-destroying philosophies and traditions of men, and, above all, looking “intently at the Chief Agent and Perfecter of our faith, Jesus.”—Heb 12:1, 2; Jude 3, 4; Ga 5:19-21; 1Ti 6:9, 10; Col 2:8.
The word “faith” is translated from the Greek piʹstis, primarily conveying the thought of confidence, trust, firm persuasion. Depending on the context, the Greek word may also be understood to mean “faithfulness” or “fidelity.”—1Th 3:7; Tit 2:10.
The Scriptures tell us: “Faith is the assured expectation of things hoped for, the evident demonstration of realities though not beheld.” (Heb 11:1) “Assured expectation” translates the Greek word hy·poʹsta·sis. This term is common in ancient papyrus business documents. It conveys the idea of something that underlies visible conditions and guarantees a future possession. In view of this, Moulton and Milligan suggest the rendering: “Faith is the title deed of things hoped for.” (Vocabulary of the Greek Testament, 1963, p. 660) The Greek word eʹleg·khos, rendered “evident demonstration,” conveys the idea of bringing forth evidence that demonstrates something, particularly something contrary to what appears to be the case. Thereby this evidence makes clear what has not been discerned before and so refutes what has only appeared to be the case. “The evident demonstration,” or evidence for conviction, is so positive or powerful that faith is said to be it.
Faith is, therefore, the basis for hope and the evidence for conviction concerning unseen realities. The entire body of truths delivered by Jesus Christ and his inspired disciples constitutes the true Christian “faith.” (Joh 18:37; Ga 1:7-9; Ac 6:7; 1Ti 5:8) Christian faith is based on the complete Word of God, including the Hebrew Scriptures, to which Jesus and the writers of the Christian Greek Scriptures frequently referred in support of their statements.
Faith is based on concrete evidence. The visible creative works testify to the existence of an invisible Creator. (Ro 1:20) The actual occurrences taking place during the ministry and earthly life of Jesus Christ identify him as the Son of God. (Mt 27:54; see JESUS CHRIST.) God’s record of providing for his earthly creatures serves as a valid basis for believing that he will surely provide for his servants, and his record as a Giver and Restorer of life lends ample evidence to the credibility of the resurrection hope. (Mt 6:26, 30, 33; Ac 17:31; 1Co 15:3-8, 20, 21) Furthermore, the reliability of God’s Word and the accurate fulfillment of its prophecies instill confidence in the realization of all of His promises. (Jos 23:14) Thus, in these many ways, “faith follows the thing heard.”—Ro 10:17; compare Joh 4:7-30, 39-42; Ac 14:8-10.
So faith is not credulity. The person who may ridicule faith usually has faith himself in tried and trusted friends. The scientist has faith in the principles of his branch of science. He bases new experiments on past discoveries and looks for new discoveries on the basis of those things already established as true. Likewise, the farmer prepares his soil and sows the seed, expecting, as in previous years, that the seed will sprout and that the plants will grow as they receive the needed moisture and sunshine. Therefore faith in the stability of the natural laws governing the universe actually constitutes a foundation for man’s plans and activities. Such stability is alluded to by the wise writer of Ecclesiastes: “The sun also has flashed forth, and the sun has set, and it is coming panting to its place where it is going to flash forth. The wind is going to the south, and it is circling around to the north. Round and round it is continually circling, and right back to its circlings the wind is returning. All the winter torrents are going forth to the sea, yet the sea itself is not full. To the place where the winter torrents are going forth, there they are returning so as to go forth.”—Ec 1:5-7.
In the Hebrew Scriptures, the word ʼa·manʹ and other words closely related convey the sense of trustworthiness, faithfulness, steadiness, steadfastness, being firmly established, long-lasting. (Ex 17:12; De 28:59; 1Sa 2:35; 2Sa 7:16; Ps 37:3) One related noun (ʼemethʹ) usually denotes “truth,” but also “faithfulness” or “trustworthiness.” (2Ch 15:3, ftn; 2Sa 15:20; compare Ne 7:2, ftn.) The familiar term “Amen” (Heb., ʼa·menʹ) also comes from ʼa·manʹ.—See AMEN.
Ancient Examples of Faith. Each one of the “so great a cloud of witnesses” mentioned by Paul (Heb 12:1) had a valid basis for faith. For example, Abel certainly knew about God’s promise concerning a “seed” that would bruise “the serpent” in the head. And he saw tangible evidences of the fulfillment of the sentence Jehovah pronounced upon his parents in Eden. Outside Eden, Adam and his family ate bread in the sweat of their face because the ground was cursed and, therefore, produced thorns and thistles. Likely Abel observed that Eve’s craving was for her husband and that Adam dominated his wife. Undoubtedly his mother commented about the pain attending her pregnancy. Then, too, the entrance to the garden of Eden was being guarded by cherubs and the flaming blade of a sword. (Ge 3:14-19, 24) All of this constituted an “evident demonstration,” giving Abel the assurance that deliverance would come through the ‘seed of promise.’ Therefore, prompted by faith, he “offered God a sacrifice,” one that proved to be of greater worth than that of Cain.—Heb 11:1, 4.
Abraham had a firm basis for faith in a resurrection, for he and Sarah had experienced the miraculous restoration of their reproductive powers, which was, in a sense, comparable to a resurrection, allowing Abraham’s family line to continue through Sarah. Isaac was born as the result of this miracle. When told to offer up Isaac, Abraham had faith that God would resurrect his son. He based such faith on God’s promise: “It is by means of Isaac that what will be called your seed will be.”—Ge 21:12; Heb 11:11, 12, 17-19.
Evidence for genuine conviction was also involved in the case of those who came to or who were brought to Jesus to be healed. Even if not eyewitnesses personally, they at least had heard about Jesus’ powerful works. Then, on the basis of what they saw or heard, they concluded that Jesus could heal them also. Moreover, they were acquainted with God’s Word and thus were familiar with the miracles performed by the prophets in times past. Upon hearing Jesus, some concluded that he was “The Prophet,” and others that he was “the Christ.” In view of this, it was most fitting for Jesus on occasion to say to those who were healed, “Your faith has made you well.” Had those persons not exercised faith in Jesus, they would not have approached him in the first place and, therefore, would not have received healing for themselves.—Joh 7:40, 41; Mt 9:22; Lu 17:19.
Likewise, the great faith of the army officer who entreated Jesus in behalf of his manservant rested on evidence, on the basis of which he concluded that Jesus’ merely ‘saying the word’ would result in the healing of his manservant. (Mt 8:5-10, 13) However, we note that Jesus healed all who came to him, not requiring faith greater or less according to their disease, nor failing to heal any of these with the excuse that he could not do it because their faith was not strong enough. Jesus performed these healings as a witness, to establish faith. In his home territory, where much unfaithfulness was expressed, he chose not to perform many powerful works, not because of inability, but because the people refused to listen and were unworthy.—Mt 13:58.
Christian Faith. To be acceptable to God, it is now necessary for one to exercise faith in Jesus Christ, and this makes possible a righteous standing with God. (Ga 2:16) Those lacking such faith are rejected by Jehovah.—Joh 3:36; compare Heb 11:6.
Faith is not the possession of all persons, as it is a fruit of God’s spirit. (2Th 3:2; Ga 5:22) And a Christian’s faith is not static, but it grows. (2Th 1:3) Hence, the request of Jesus’ disciples, “Give us more faith,” was very appropriate, and he did provide them the foundation for increased faith. He supplied them with greater evidence and understanding on which to base their faith.—Lu 17:5.
The entire life course of a Christian is actually governed by faith, enabling him to overcome mountainlike obstacles that would hinder his service to God. (2Co 5:7; Mt 21:21, 22) Additionally, there must be works consistent with and in display of faith, but works of the Mosaic Law are not required. (Jas 2:21-26; Ro 3:20) Trials can strengthen faith. Faith serves as a protective shield in the Christian’s spiritual warfare, helping him to overcome the Devil and be a conqueror of the world.—1Pe 1:6, 7; Eph 6:16; 1Pe 5:9; 1Jo 5:4.
But faith cannot be taken for granted, because lack of faith is ‘the sin that so easily entangles one.’ To maintain a firm faith requires putting up a hard fight for it, resisting men who could plunge one into immorality, combating the works of the flesh, avoiding the snare of materialism, shunning faith-destroying philosophies and traditions of men, and, above all, looking “intently at the Chief Agent and Perfecter of our faith, Jesus.”—Heb 12:1, 2; Jude 3, 4; Ga 5:19-21; 1Ti 6:9, 10; Col 2:8.
Still trying to deny the undeniable.
New Precambrian Embryos Are Equivocal at Best
Evolution News & Views
Precambrian embryos? Old news. Paleontologists have been looking at them for over a decade, yet the Cambrian explosion remains one of the strongest empirical challenges against Darwin's theory. A new paper tries to show that some of them were "possibly" embryos of metazoan animals that emerged long before the explosion, thereby lengthening the time during which evolution could have worked its magic.
In Darwin's Doubt, Stephen Meyer pointed to the embryos as evidence against the "artifact hypothesis." This hypothesis tried to explain the lack of Precambrian ancestors as an artifact of poor fossil preservation. "If these strata could preserve embryos," Meyer said, "then they should have preserved fully developed animals -- at least, if such animals were present at the time" (p. 68). Illustra Media's film Darwin's Dilemma includes Paul Chien, who worked with Dr. J.Y. Chen at the discovery site in China, dissecting some of the fossils, showing them under the microscope to be characteristic of sponge embryos.
The embryos come from the Precambrian Doushantuo formation in China, dated at 600 million years old -- about 60 million years before the onset of the Cambrian Explosion. This was the Ediacaran period, populated by strange-looking sessile colonies of unknown organisms. Meyer discusses the Ediacaran in detail in his book, documenting that most leading evolutionary paleontologists consider the Ediacaran creatures to be unrelated to the Cambrian animals. Meyer readily acknowledges the presence of sponges and possibly two other phyla before the explosion. The problem for evolutionists is to explain the geologically sudden appearance of almost twenty new phyla with new body plans more complex than sponges or anything else that came before - animals with jointed legs, guts, eyes, hard parts, and locomotion. Some of the phyla, like trilobites and Marrella, exhibit bilateral symmetry. These were the first bilaterians: a group that includes us.
Darwin himself confessed that "if numerous species, belonging to the same genera or families, have really started into life all at once, the fact would be fatal to the theory of descent with slow modification through natural selection" (quoted in Meyer, p. 17). His disciples ever since have scoured the earth for evidence of the missing Cambrian ancestors in the strata below. All they have found are microbes, sponges, the Ediacaran biota, and the embryos. A few small shelly fossils appear at the base of the Cambrian (see Debating Darwin's Doubt, Chapters 13-14, for details), but experts consider the Precambrian evidence to be insufficient to account for the profusion of new body plans in the Cambrian explosion.
To muffle the explosion, evolutionists have used two strategies to construct a "long fuse" of gradual evolutionary experimentation. One has been the molecular clock. Molecular estimates of mutation rates, they say, show that the ancestors must have existed, even without fossil evidence. The argument is circular; it relies on evolution to try to prove evolution. Even so, last October, we discussed a Current Biology paper by Telford, Donoghue, and Yang who showed after a detailed analysis that molecular clock data is too imprecise to draw any conclusions.
The other strategy has been to conjure complex animals out of the Precambrian fossil record. In Darwin's Doubt, pp. 90-92, Meyer showed how David Bottjer of the University of Southern California was roundly criticized by his colleagues in 2005 for making too much of an enigmatic fossil named Vernanimalcula. Bottjer had labeled it an early bilaterian, but most others considered it to be irrelevant to the Cambrian explosion (see Casey Luskin's article from 2012 that says Vernanimalcula is possibly not even a fossil at all). Last year we showed Bottjer still suggesting Vernanimalcula was a bilaterian.
Now, in a paper in Geology co-authored by three colleagues from China and an imaging expert in France, Bottjer has more show and tell from Doushantuo. Strangely, he omits mention of Vernanimalcula, noting that for the alleged Precambrian bilaterians, "most of them are not yet widely accepted." (The reference for that comment is to a paper with a very harsh title, "A merciful death for the 'earliest bilaterian,' Vernanimalcula." Clearly the authors, Bengtson, Cunningham, Yin, and Donoghue, disagreed that it was ever "widely accepted.")
The Geology paper presents three new embryos that the authors claim show a cleavage pattern characteristic of metazoan animals, perhaps even bilaterians. Phys.org shares the gist of the new claim:
In their article for Geology, Zongjun Yin and colleagues report new Doushantuo embryo-like fossils. They used high-resolution synchrotron radiation X-ray microtomography to reconstruct three-dimensional structures of the fossils, and the results demonstrate that these fossils preserve unique features directly comparable to living animal embryos that utilize a special kind of cell division pattern known as discoidal cleavage. Given that discoidal cleavage only occurs in animal embryos, the biological affinities of these fossils are probably animals. [Emphasis added.]
Since these embryos are in the Doushantuo formation (dated 600 million years old), there must have been animals alive back then, if not earlier. Problem solved? Well, look at the images and think about the interpretation. First some terminology. In their pre-gastrula stages, embryos show either holoblastic cleavage (where the first cells all look the same size) or meroblastic cleavage (where one cell becomes a large "yolk" for the others). Discoidal cleavage is a type of meroblastic cleavage where the cells sit on top of the yolk cell without penetrating it. Identifying the type of cleavage in these phophatized embryos is the key to interpreting them, they say:
Recently, the debate on the EDEFs [Ediacaran Doushantuo Embryo-like Fossils] has begun to crystallize into two competing interpretations: (1) that the EDEFs represent crown metazoans, or (2) that they represent stem metazoans or nonmetazoan holozoans. These two competing interpretations have very different implications for the timing and tempo of animal diversification [i.e., the Cambrian explosion]. If the EDEFs are crown metazoans, a deep Precambrian history of animals is implied, whereas if they are stem or non-metazoans, the fossils do not reduce the gap between molecular clock estimates and the fossil evidence for the early divergence of metazoans. It is difficult to reconcile these competing interpretations because these morphologically simple EDEFs yield very little phylogenetic information.
And so the authors argue that the appearance of discoidal cleavage suggests that the embryos could be crown metazoans, implying "a deep Precambrian history of animals." Here are some issues:
Only one of the 3 microfossils shows "possible" discoidal cleavage; the others are ambiguous, judging from the images; they only show some cells smaller than one larger cell.
The prime example has 12 smaller cells appearing in an indentation in the large cell. They cannot rule out, however, "taphonomic bias" (artifacts from fossilization) or unequal cleavage in a holoblastic embryo.
Cleavage patterns vary widely among multicellular organisms. While no instances of discoidal cleavage have been "reported" outside of bilaterians, they are not necessarily diagnostic of bilaterians.
Many bilaterians undergo holoblastic cleavage: annelids, mollusks, echinoderms, tunicates, amphibians, some fish, and placental mammals. Some of these are Cambrian phyla; others are advanced vertebrates.
Holoblastic cleavage organisms can be organized into 5 kinds within two categories (see Wikipedia); in other words, there are variations that might be interpreted as meroblastic or discoidal in fossil conditions.
Discoidal cleavage is not universal among bilaterians; it appears in widely separated groups including some fish, sharks, birds, reptiles and monotremes (like platypus).
Fossil embryos represent only a snapshot in time of cells turned to stone. The scientists cannot watch the developmental process unfold.
The authors are hanging an awful lot of interpretation, therefore, on one 250-micrometer fossil that they acid-washed and scanned with radiation, then processed for visualization in software. If this little piece of rock is so important, why are there not hundreds of them in all stages of development? Most importantly, where are the adults? Clearly, the Doushantuo formation was capable of fossilizing higher life stages in great detail. Their absence seems better evidence than the presence of a questionable embryo that, until proven otherwise, could be another sponge. Notice the subjective interpretation in the paper, amounting to little more than possibility thinking:
Our findings support the conclusion that at least some EDEFs possibly represent crown-animals, although their phylogenetic affinity cannot be established because discoidal-type meroblastic cleavage has evolved independently in a variety of animal groups, e.g., scorpions and cephalopods as well as many vertebrates, including some fishes and amniotes.
What is it, therefore, about discoidal cleavage that is worth getting excited about? Keep in mind that Bottjer has demonstrated a strong antipathy to intelligent design, dismissing Darwin's Dilemma as "a creationist movie" in spite of its fully scientific arguments; he took part in the effort to block its showing at the California Science Center; and he promoted Vernanimalcula beyond the evidence enough to rouse the censure of his colleagues.
These points aside, what's convincing is the positive evidence for design in animal development, complex body plans and a biosphere that interacts at all levels on a privileged planet in a finely tuned universe. That's huge. That's Undeniable.
Evolution News & Views
Precambrian embryos? Old news. Paleontologists have been looking at them for over a decade, yet the Cambrian explosion remains one of the strongest empirical challenges against Darwin's theory. A new paper tries to show that some of them were "possibly" embryos of metazoan animals that emerged long before the explosion, thereby lengthening the time during which evolution could have worked its magic.
In Darwin's Doubt, Stephen Meyer pointed to the embryos as evidence against the "artifact hypothesis." This hypothesis tried to explain the lack of Precambrian ancestors as an artifact of poor fossil preservation. "If these strata could preserve embryos," Meyer said, "then they should have preserved fully developed animals -- at least, if such animals were present at the time" (p. 68). Illustra Media's film Darwin's Dilemma includes Paul Chien, who worked with Dr. J.Y. Chen at the discovery site in China, dissecting some of the fossils, showing them under the microscope to be characteristic of sponge embryos.
The embryos come from the Precambrian Doushantuo formation in China, dated at 600 million years old -- about 60 million years before the onset of the Cambrian Explosion. This was the Ediacaran period, populated by strange-looking sessile colonies of unknown organisms. Meyer discusses the Ediacaran in detail in his book, documenting that most leading evolutionary paleontologists consider the Ediacaran creatures to be unrelated to the Cambrian animals. Meyer readily acknowledges the presence of sponges and possibly two other phyla before the explosion. The problem for evolutionists is to explain the geologically sudden appearance of almost twenty new phyla with new body plans more complex than sponges or anything else that came before - animals with jointed legs, guts, eyes, hard parts, and locomotion. Some of the phyla, like trilobites and Marrella, exhibit bilateral symmetry. These were the first bilaterians: a group that includes us.
Darwin himself confessed that "if numerous species, belonging to the same genera or families, have really started into life all at once, the fact would be fatal to the theory of descent with slow modification through natural selection" (quoted in Meyer, p. 17). His disciples ever since have scoured the earth for evidence of the missing Cambrian ancestors in the strata below. All they have found are microbes, sponges, the Ediacaran biota, and the embryos. A few small shelly fossils appear at the base of the Cambrian (see Debating Darwin's Doubt, Chapters 13-14, for details), but experts consider the Precambrian evidence to be insufficient to account for the profusion of new body plans in the Cambrian explosion.
To muffle the explosion, evolutionists have used two strategies to construct a "long fuse" of gradual evolutionary experimentation. One has been the molecular clock. Molecular estimates of mutation rates, they say, show that the ancestors must have existed, even without fossil evidence. The argument is circular; it relies on evolution to try to prove evolution. Even so, last October, we discussed a Current Biology paper by Telford, Donoghue, and Yang who showed after a detailed analysis that molecular clock data is too imprecise to draw any conclusions.
The other strategy has been to conjure complex animals out of the Precambrian fossil record. In Darwin's Doubt, pp. 90-92, Meyer showed how David Bottjer of the University of Southern California was roundly criticized by his colleagues in 2005 for making too much of an enigmatic fossil named Vernanimalcula. Bottjer had labeled it an early bilaterian, but most others considered it to be irrelevant to the Cambrian explosion (see Casey Luskin's article from 2012 that says Vernanimalcula is possibly not even a fossil at all). Last year we showed Bottjer still suggesting Vernanimalcula was a bilaterian.
Now, in a paper in Geology co-authored by three colleagues from China and an imaging expert in France, Bottjer has more show and tell from Doushantuo. Strangely, he omits mention of Vernanimalcula, noting that for the alleged Precambrian bilaterians, "most of them are not yet widely accepted." (The reference for that comment is to a paper with a very harsh title, "A merciful death for the 'earliest bilaterian,' Vernanimalcula." Clearly the authors, Bengtson, Cunningham, Yin, and Donoghue, disagreed that it was ever "widely accepted.")
The Geology paper presents three new embryos that the authors claim show a cleavage pattern characteristic of metazoan animals, perhaps even bilaterians. Phys.org shares the gist of the new claim:
In their article for Geology, Zongjun Yin and colleagues report new Doushantuo embryo-like fossils. They used high-resolution synchrotron radiation X-ray microtomography to reconstruct three-dimensional structures of the fossils, and the results demonstrate that these fossils preserve unique features directly comparable to living animal embryos that utilize a special kind of cell division pattern known as discoidal cleavage. Given that discoidal cleavage only occurs in animal embryos, the biological affinities of these fossils are probably animals. [Emphasis added.]
Since these embryos are in the Doushantuo formation (dated 600 million years old), there must have been animals alive back then, if not earlier. Problem solved? Well, look at the images and think about the interpretation. First some terminology. In their pre-gastrula stages, embryos show either holoblastic cleavage (where the first cells all look the same size) or meroblastic cleavage (where one cell becomes a large "yolk" for the others). Discoidal cleavage is a type of meroblastic cleavage where the cells sit on top of the yolk cell without penetrating it. Identifying the type of cleavage in these phophatized embryos is the key to interpreting them, they say:
Recently, the debate on the EDEFs [Ediacaran Doushantuo Embryo-like Fossils] has begun to crystallize into two competing interpretations: (1) that the EDEFs represent crown metazoans, or (2) that they represent stem metazoans or nonmetazoan holozoans. These two competing interpretations have very different implications for the timing and tempo of animal diversification [i.e., the Cambrian explosion]. If the EDEFs are crown metazoans, a deep Precambrian history of animals is implied, whereas if they are stem or non-metazoans, the fossils do not reduce the gap between molecular clock estimates and the fossil evidence for the early divergence of metazoans. It is difficult to reconcile these competing interpretations because these morphologically simple EDEFs yield very little phylogenetic information.
And so the authors argue that the appearance of discoidal cleavage suggests that the embryos could be crown metazoans, implying "a deep Precambrian history of animals." Here are some issues:
Only one of the 3 microfossils shows "possible" discoidal cleavage; the others are ambiguous, judging from the images; they only show some cells smaller than one larger cell.
The prime example has 12 smaller cells appearing in an indentation in the large cell. They cannot rule out, however, "taphonomic bias" (artifacts from fossilization) or unequal cleavage in a holoblastic embryo.
Cleavage patterns vary widely among multicellular organisms. While no instances of discoidal cleavage have been "reported" outside of bilaterians, they are not necessarily diagnostic of bilaterians.
Many bilaterians undergo holoblastic cleavage: annelids, mollusks, echinoderms, tunicates, amphibians, some fish, and placental mammals. Some of these are Cambrian phyla; others are advanced vertebrates.
Holoblastic cleavage organisms can be organized into 5 kinds within two categories (see Wikipedia); in other words, there are variations that might be interpreted as meroblastic or discoidal in fossil conditions.
Discoidal cleavage is not universal among bilaterians; it appears in widely separated groups including some fish, sharks, birds, reptiles and monotremes (like platypus).
Fossil embryos represent only a snapshot in time of cells turned to stone. The scientists cannot watch the developmental process unfold.
The authors are hanging an awful lot of interpretation, therefore, on one 250-micrometer fossil that they acid-washed and scanned with radiation, then processed for visualization in software. If this little piece of rock is so important, why are there not hundreds of them in all stages of development? Most importantly, where are the adults? Clearly, the Doushantuo formation was capable of fossilizing higher life stages in great detail. Their absence seems better evidence than the presence of a questionable embryo that, until proven otherwise, could be another sponge. Notice the subjective interpretation in the paper, amounting to little more than possibility thinking:
Our findings support the conclusion that at least some EDEFs possibly represent crown-animals, although their phylogenetic affinity cannot be established because discoidal-type meroblastic cleavage has evolved independently in a variety of animal groups, e.g., scorpions and cephalopods as well as many vertebrates, including some fishes and amniotes.
What is it, therefore, about discoidal cleavage that is worth getting excited about? Keep in mind that Bottjer has demonstrated a strong antipathy to intelligent design, dismissing Darwin's Dilemma as "a creationist movie" in spite of its fully scientific arguments; he took part in the effort to block its showing at the California Science Center; and he promoted Vernanimalcula beyond the evidence enough to rouse the censure of his colleagues.
These points aside, what's convincing is the positive evidence for design in animal development, complex body plans and a biosphere that interacts at all levels on a privileged planet in a finely tuned universe. That's huge. That's Undeniable.
When religious extremists collide.
Students, Scientism, and Straw Men
Sarah Chaffee
At the NPR website, Barbara King, an anthropologist at the College of William and Mary, recently addressed Ken Ham's Ark Encounter, stating that we could use more "explicit pushback to anti-science creationist discourse" ("There's No Controversy: Let's Stop Failing Our Children on Evolution"). She recommends that readers speak to local school boards and media, educate their children on evolution at home, and ask politicians about their views on origins. Deluged with comments and emails, King sought to address readers' concerns in a follow-up article ("When Science Stands Up To Creationism").
Unfortunately, she frames skepticism on evolution in the familiar but mistaken terms of religion vs. science. Her narrow critique focuses on things like whether dinosaurs and humans coexisted -- "'walked hand-in-hand' a few thousand years ago" -- rather than grappling with peer-reviewed research that questions neo-Darwinism.
King eschews the term "scientism" -- but does she advocate for it? Describing comments she received on her first article, she notes there was "genuine concern that evolutionary scientists, including me, advocate forcing children to learn one way and one way only." Her response does not alleviate that concern.
She does not bother to rebut intelligent design. After quoting responses that talk about the freedom to believe and about learning all of the evidence, she notes, "So in response to these remarks and others like them, let me say it loud and clear: Freedom to believe anything one wants in the religious sphere is incredibly important." But she goes on to state: "Science isn't about belief." King buys into the simplistic equation of science, whatever it may say at the moment, with "truth." She accordingly dismisses the scientific controversy over neo-Darwinism.
Her description of how science works fits the current state of the evolution debate quite well. She notes, "[Science is] about testing hypotheses, and always seeking out both alternative explanations and data-driven corrections to previous conclusions." King quotes one of the comments left on her article:
Science is the process of learning what is where in the world of knowledge; and we are constantly developing better tools to make better measurements. We are constantly re-drawing the stuff that we suspect might be out there, slowly getting closer and closer to getting the stuff beyond the boundaries of knowledge successfully mapped out, and firmly within the boundaries of what we know. This means there will be a new frontier, and new questions, and maybe some corrections along the way.
If King really believes science is about continuous corrections and questions, she should be friendlier to teaching the scientific controversy over evolution, which attempts to do just that. A growing number of scientists hold that natural selection acting on random mutations cannot fully account for the diversity of life.
In The Edge of Evolution, biochemist Michael Behe examines mutations necessary to develop chloroquine resistance by malaria parasites, and concludes that two simultaneous mutations is the most evolution can accomplish. Furthermore, based on population sizes and frequency of mutations arising, he says, "No mutation that is of the same complexity as chloroquine resistance in malaria arose by Darwinian evolution in the line leading to humans in the past ten million years."
Engaging with the evidence is important -- and so is freedom to discuss dissenting ideas.
King quotes a response from John Ellis, writing at PJ Media, who suggested that her reasoning points to the worldview of scientism. But she opts not to quote the end of his response, which makes clear that objecting to scientism isn't tied to any particular religious belief. A couple of sentences she left out are quite insightful:
You don't need to believe that the earth is only six thousand years old and that dinosaurs walked the earth at the same time as humans in order to see the danger in surrendering the control over education to Barbara King. Regardless of what you think about Ken Ham and Answers in Genesis, it's important to guard the freedom of ideas for all.
Gee, I wonder what Professor King would say in response to a book like Axe's Undeniable, which explores many of the serious, scientific objections to Darwinian evolution. We'll probably never know. Dodging the evidence seems to suit her much better.
Darwinism Vs. the real world XXXIII
When You Don't Have Time to Think: Reflexes
Howard Glicksman
Editor's note: Physicians have a special place among the thinkers who have elaborated the argument for intelligent design. Perhaps that's because, more than evolutionary biologists, they are familiar with the challenges of maintaining a functioning complex system, the human body. With that in mind, Evolution News is delighted to offer this series, "The Designed Body." For the complete series, see here. Dr. Glicksman practices palliative medicine for a hospice organization.
It is our muscles, controlled by our nerves, that allow us to breathe, swallow, move around, and handle things. The peripheral nerves send sensory information about what is going on outside and inside the body to the spinal cord and the brain and from them send back instructions to the muscles to tell them what to do. In my last few articles, I described the sensory receptors, which act as transducers, converting phenomena into information the body can use to survive.
The vestibular apparatus, which detects body motion, and the cochlea, which detects sound, are housed within the inner ear. Light is detected by the retina at the back of the eye. Pressure, light touch, motion, vibration, hot and cold, and pain are detected by sensory receptors in the skin that tell the body what's going on around it. Other receptors keep tabs on what's going on within many of the body's organs.
To control the musculoskeletal system, so it can do what it needs to do, the body uses the proprioceptors located in the joints, tendons, and muscles. In general, purposeful movements are done voluntarily. But to maintain its position or avoid serious injury, sometimes the body must act quickly so that these reflexive movements are done unconsciously. Let's look at how some of these automatic reflexes work to prevent organ damage and help maintain the body's position so that goal directed activities can be done. Keep in mind that when evolutionary biologists tell us about how life arose, they only deal with how it looks and not how it must actually work within the laws of nature to survive. Ask yourself which is a more plausible explanation for how life arose: chance and the laws of nature alone or intelligent design?
A reflex is an involuntary, pre-programmed, automatic motor response to a stimulus that comes about without conscious direction from the brain. It works through the spinal cord and brainstem and serves to protect the body from injury and to maintain its position while the mind is focused elsewhere. For example, the slightest touch of the cornea in the eye triggers blinking immediately. Shining a bright light into the eyes instantaneously makes the pupils close. Without these automatic and quick reflexes, our eyes would be at high risk for injury because the time it would take for our brain to assess the situation and implement a plan to avoid injury would not be fast enough to prevent serious damage.
The simplest reflex, involving just one sensory nerve sending a message to just one motor nerve, is the stretch reflex. The patellar reflex, where tapping on the tendon of a bent knee suddenly straightens it out is the classic example. Tapping the patellar tendon stretches the muscle spindles in the quadriceps muscle, sending nerve impulses through the sensory nerve to the spinal cord. If the impulses are strong enough to stimulate the motor nerve, it instructs the quadriceps to contract, causing the knee to go into extension.
The stretch reflexes are important for maintaining posture and position. Standing with the knees extended for some time eventually results in fatigue of the quadriceps and puts the body at risk of falling. The resulting stretch of the muscle spindles activates the patellar reflex and stimulates the quadriceps to contract more, which stabilizes the knee and prevents a fall. This recovery of posture function takes place throughout the body because the stretch reflex operates in all of the muscles, whether in the head and neck, the arms and legs, or the spinal column.
However the ability for the stretch reflex to maintain the body's position wouldn't be possible without reflex inhibition. The movement of a bone across a joint in any direction usually depends on two complementary muscles working in opposite directions. The quadriceps extends the knee and the biceps femoris flexes it. The patellar reflex not only causes the quadriceps to contract but simultaneously sends nerve messages to relax the biceps femoris. Without reflex inhibition the complementary muscles would constantly be fighting a tug of war with each other and coordinated muscle function would be impossible.
Another important but more complex pattern used by the body to protect itself from injury while maintaining its position is the withdrawal (flexor) and crossed extensor reflexes. If you step on something hot or sharp, the pain messages quickly go to the spinal cord where it stimulates a series of flexor muscles to contract so that you immediately withdraw your foot. But when you lift your leg off the ground, you are at risk of falling. So a split second later, the crossed extensor reflex straightens out your other leg and your body weight shifts over it to maintain your balance. You barely think about any of this -- your body knows to do it naturally.
When it comes to life, real numbers have real consequences. When you stand up your buttocks is about one meter off the ground. If your quadriceps weaken or you suddenly lift your leg off the ground to avoid pain, gravity immediately kicks in. Since gravity makes all things accelerate to the ground at 10 m/sec2, it is possible to calculate how long it would take for you to hit it from one meter up (0.45 sec). This means that your nervous system would have to be able to react fast enough to prevent a fall -- less than half a second.
The impulse velocity of a nerve is faster if it is larger in diameter and insulated with a fatty substance called myelin, rather than smaller and unmyelinated. Normally, the sensory and motor nerves involved in the abovementioned reflexes are large and myelinated and have an impulse velocity of about 100 m/sec (> 200 mph). Since it is about one meter from the foreleg to the lower spinal cord, it only takes about 0.02 sec (0.01 + 0.01) for the nerve impulse to travel along the sensory nerve to the spinal cord and back along the motor nerve for these reflexes to work in time to keep you balanced and on your feet. This would give the neuromuscular system plenty of time to make changes to prevent a fall (0.45 sec).
In contrast, the impulse velocity of the smaller and unmyelinated nerves that inform the body about pain is only about one meter/sec. This means that if the sensory and motor nerves involved in these reflexes were like the pain nerve fibers, it would take at least two seconds for the impulses to go from the leg to the spinal cord and back again. Clearly, this would not be fast enough to prevent you from falling (0.45 sec). This also explains why, when you are injured you can react very quickly to avoid further tissue damage but you don't experience the severe pain until a few seconds later.
The system of reflexes the body uses to protect itself from injury and maintain its position is irreducibly complex because of the different nerve and muscle cells it needs to work. But it also demonstrates natural survival capacity in that the impulse velocity of the sensory and motor nerves involved in these reflexes is sufficient to contend with the force of gravity. Without this, no matter how sophisticated their reflexes, it would have been impossible for our earliest ancestors to maintain their position and survive.
Evolutionary biologists imagine how these systems came into being by how they look, but they rarely seem to think that it's also important to explain how they happen to work within the laws of nature. Next time we'll look at what it takes for the body to keep its balance.
Howard Glicksman
Editor's note: Physicians have a special place among the thinkers who have elaborated the argument for intelligent design. Perhaps that's because, more than evolutionary biologists, they are familiar with the challenges of maintaining a functioning complex system, the human body. With that in mind, Evolution News is delighted to offer this series, "The Designed Body." For the complete series, see here. Dr. Glicksman practices palliative medicine for a hospice organization.
It is our muscles, controlled by our nerves, that allow us to breathe, swallow, move around, and handle things. The peripheral nerves send sensory information about what is going on outside and inside the body to the spinal cord and the brain and from them send back instructions to the muscles to tell them what to do. In my last few articles, I described the sensory receptors, which act as transducers, converting phenomena into information the body can use to survive.
The vestibular apparatus, which detects body motion, and the cochlea, which detects sound, are housed within the inner ear. Light is detected by the retina at the back of the eye. Pressure, light touch, motion, vibration, hot and cold, and pain are detected by sensory receptors in the skin that tell the body what's going on around it. Other receptors keep tabs on what's going on within many of the body's organs.
To control the musculoskeletal system, so it can do what it needs to do, the body uses the proprioceptors located in the joints, tendons, and muscles. In general, purposeful movements are done voluntarily. But to maintain its position or avoid serious injury, sometimes the body must act quickly so that these reflexive movements are done unconsciously. Let's look at how some of these automatic reflexes work to prevent organ damage and help maintain the body's position so that goal directed activities can be done. Keep in mind that when evolutionary biologists tell us about how life arose, they only deal with how it looks and not how it must actually work within the laws of nature to survive. Ask yourself which is a more plausible explanation for how life arose: chance and the laws of nature alone or intelligent design?
A reflex is an involuntary, pre-programmed, automatic motor response to a stimulus that comes about without conscious direction from the brain. It works through the spinal cord and brainstem and serves to protect the body from injury and to maintain its position while the mind is focused elsewhere. For example, the slightest touch of the cornea in the eye triggers blinking immediately. Shining a bright light into the eyes instantaneously makes the pupils close. Without these automatic and quick reflexes, our eyes would be at high risk for injury because the time it would take for our brain to assess the situation and implement a plan to avoid injury would not be fast enough to prevent serious damage.
The simplest reflex, involving just one sensory nerve sending a message to just one motor nerve, is the stretch reflex. The patellar reflex, where tapping on the tendon of a bent knee suddenly straightens it out is the classic example. Tapping the patellar tendon stretches the muscle spindles in the quadriceps muscle, sending nerve impulses through the sensory nerve to the spinal cord. If the impulses are strong enough to stimulate the motor nerve, it instructs the quadriceps to contract, causing the knee to go into extension.
The stretch reflexes are important for maintaining posture and position. Standing with the knees extended for some time eventually results in fatigue of the quadriceps and puts the body at risk of falling. The resulting stretch of the muscle spindles activates the patellar reflex and stimulates the quadriceps to contract more, which stabilizes the knee and prevents a fall. This recovery of posture function takes place throughout the body because the stretch reflex operates in all of the muscles, whether in the head and neck, the arms and legs, or the spinal column.
However the ability for the stretch reflex to maintain the body's position wouldn't be possible without reflex inhibition. The movement of a bone across a joint in any direction usually depends on two complementary muscles working in opposite directions. The quadriceps extends the knee and the biceps femoris flexes it. The patellar reflex not only causes the quadriceps to contract but simultaneously sends nerve messages to relax the biceps femoris. Without reflex inhibition the complementary muscles would constantly be fighting a tug of war with each other and coordinated muscle function would be impossible.
Another important but more complex pattern used by the body to protect itself from injury while maintaining its position is the withdrawal (flexor) and crossed extensor reflexes. If you step on something hot or sharp, the pain messages quickly go to the spinal cord where it stimulates a series of flexor muscles to contract so that you immediately withdraw your foot. But when you lift your leg off the ground, you are at risk of falling. So a split second later, the crossed extensor reflex straightens out your other leg and your body weight shifts over it to maintain your balance. You barely think about any of this -- your body knows to do it naturally.
When it comes to life, real numbers have real consequences. When you stand up your buttocks is about one meter off the ground. If your quadriceps weaken or you suddenly lift your leg off the ground to avoid pain, gravity immediately kicks in. Since gravity makes all things accelerate to the ground at 10 m/sec2, it is possible to calculate how long it would take for you to hit it from one meter up (0.45 sec). This means that your nervous system would have to be able to react fast enough to prevent a fall -- less than half a second.
The impulse velocity of a nerve is faster if it is larger in diameter and insulated with a fatty substance called myelin, rather than smaller and unmyelinated. Normally, the sensory and motor nerves involved in the abovementioned reflexes are large and myelinated and have an impulse velocity of about 100 m/sec (> 200 mph). Since it is about one meter from the foreleg to the lower spinal cord, it only takes about 0.02 sec (0.01 + 0.01) for the nerve impulse to travel along the sensory nerve to the spinal cord and back along the motor nerve for these reflexes to work in time to keep you balanced and on your feet. This would give the neuromuscular system plenty of time to make changes to prevent a fall (0.45 sec).
In contrast, the impulse velocity of the smaller and unmyelinated nerves that inform the body about pain is only about one meter/sec. This means that if the sensory and motor nerves involved in these reflexes were like the pain nerve fibers, it would take at least two seconds for the impulses to go from the leg to the spinal cord and back again. Clearly, this would not be fast enough to prevent you from falling (0.45 sec). This also explains why, when you are injured you can react very quickly to avoid further tissue damage but you don't experience the severe pain until a few seconds later.
The system of reflexes the body uses to protect itself from injury and maintain its position is irreducibly complex because of the different nerve and muscle cells it needs to work. But it also demonstrates natural survival capacity in that the impulse velocity of the sensory and motor nerves involved in these reflexes is sufficient to contend with the force of gravity. Without this, no matter how sophisticated their reflexes, it would have been impossible for our earliest ancestors to maintain their position and survive.
Evolutionary biologists imagine how these systems came into being by how they look, but they rarely seem to think that it's also important to explain how they happen to work within the laws of nature. Next time we'll look at what it takes for the body to keep its balance.
Subscribe to:
Posts (Atom)