Thursday 27 April 2017
On recent attempts to explain(away) the Cambrian explosion.
This Just In — Latest Cambrian Explosion Excuses
Evolution News | @DiscoveryCSC
When evolutionists deny design, but admit that nature looks designed, they often wind up attributing the skills of a designer to inanimate matter. This is absurd, but what else is available in their explanatory toolkit?
Here’s an example. A headline by Amanda Doyle at NASA’s Astrobiology Magazine reads, “Microbes set the stage for the first animals.” How is this to be understood? Are animals waiting offstage for their debut? Are microbes arranging the props, clearing pathways, and turning on the lights? Surely she cannot mean that. So how can it be understood without personification? Assuming the prior existence of microbes, perhaps she means that their collective behavior resulted in changes in the balances of gases in the atmosphere, or the pH of seawater, or some other unplanned consequence. Does that help?
Doyle focuses on evidence dating from the Ediacaran Period, just prior to the Cambrian explosion. She weaves her plot around the story of a team from the University of Wisconsin-Madison working in Siberia. Photos show their tools beside unusual limestone rocks containing stromatolites and algal impressions. The photos don’t appear to show any Ediacaran creatures themselves. Indeed, those creatures play no role in her play, so they exit stage right: “The remains of these odd creatures, most of which have no evidence of a circulatory or digestive system, largely vanished from the rock record at the start of the Cambrian Period,” she admits [emphasis added], essentially agreeing with the scientists whom Stephen Meyer quotes in Chapter 4 of Darwin’s Doubt.
According to Doyle’s headline, microbes were recruited as the explanatory heroes in her play. Microbes altered the sediments, leaving records of levels of oxygen and sulfur at the time. The UW team found a stratum where “environmental conditions apparently changed,” going from euxinic (sulfidic) conditions that favored microbe growth to oxygenic conditions that would have favored animals.
The change from euxinic to non-euxinic conditions at the end of the Ediacaran Period allowed the Ediacaran animals to colonise the now more oxidized and habitable ocean, despite an overall oxygen level in the atmosphere and oceans that was far less than today’s.
We need go no further. This is a rehash of the Oxygen Theory we have dealt with over and over (for the latest, see here and here). It makes no sense; oxygen has no power to create animal body plans, nor can it “allow” the animals to create themselves. Mr. Oxygen can cry out, “Bring forth! I allow you to evolve!” all he wants on the stage, but nothing will happen. Can’t someone answer the real argument of Darwin’s Doubt, that the abrupt increase in functional information in the Cambrian animals requires a cause that is capable of producing it? The only such cause we know from uniform experience is intelligence. Oxygen has no such power.
We learn at the end of the article that “The research was supported by the Exobiology and Evolutionary Biology element of the NASA Astrobiology Program.” But Darwin’s Doubt came out four years ago, and Debating Darwin’s Doubt two years later. Is NASA really unaware of the challenge?
Let’s keep looking for an explanation that’s new and different. Here’s one: in Science Advances, the open-access journal of the AAAS, a team of six from four American universities spices up the story of the Cambrian.
Several positive carbon isotope excursions in Lower Paleozoic rocks, including the prominent Upper Cambrian Steptoean Positive Carbon Isotope Excursion (SPICE), are thought to reflect intermittent perturbations in the hydrosphere-biosphere system. Models explaining these secular changes are abundant, but the synchronicity and regional variation of the isotope signals are not well understood. Examination of cores across a paleodepth gradient in the Upper Cambrian central Missouri intrashelf basin (United States) reveals a time-transgressive, facies-dependent nature of the SPICE. Although the SPICE event may be a global signal, the manner in which it is recorded in rocks should and does vary as a function of facies and carbonate platform geometry. We call for a paradigm shift to better constrain facies, stratigraphic, and biostratigraphic architecture and to apply these observations to the variability in magnitude, stratigraphic extent, and timing of the SPICE signal, as well as other biogeochemical perturbations, to elucidate the complex processes driving the ocean-carbonate system.
Further reading doesn’t help. The authors know that “The Early Paleozoic era … encompasses an important time frame in metazoan evolution, including the Cambrian Explosion,” but their research only focuses on correlation, not causation. They mention the same “increase in atmospheric oxygen, possibly associated with an oceanic anoxic/euxinic event” that Amanda Doyle focused on.
Conceptual models have been constructed to explain the causes and effects of these sundry secular changes, including ocean anoxia/euxinia driving trilobite turnover, associated enhancement of organic carbon and pyrite burial forcing changes in atmospheric oxygen levels, and oxygenated coastal waters driving the diversification of plankton and perhaps the resulting Ordovician biodiversification.
The changes could well be consequences, not causes, of the Cambrian explosion. And whether the element is oxygen, sulfur, carbon, or anything else, it doesn’t matter. They’re inert. They’re dumb. None of them has creative powers to design new body plans, cell types, and organs, even if they were to “allow” such things to “emerge” onstage.
We’ll try one more. In Geology, the Ediacaran animal Cloudina is mentioned in a paper by seven researchers from Scotland, Russia, and Namibia. Do they describe a sufficient cause for the Cambrian animals?
The Ediacaran skeletal tubular putative metazoan Cloudina occurs globally in carbonate settings, which both provided lithified substrates and minimized the cost of skeletonization. Habitat and substrate preferences and the relationship of Cloudina to other metazoans have not been fully documented, so we know little as to its ecological demands or community dynamics. In situ Cloudina from the Nama Group, Namibia (ca. 550–541 Ma), formed mutually attached reefs composed of successive assemblages in shallow, high-energy environments, and also communities attached to either stromatolites in storm-influenced deep inner-ramp settings or thin microbial mats in lower-energy habitats. Each assemblage shows statistically distinct tube diameter cohorts, but in sum, Cloudina shows an exponential frequency distribution of diameter size.
Meyer doesn’t mention Cloudina, but it’s not much to look at. Visualize a stack of cups forming a tube. The Virtual Fossil Museum says, “The Cloudinids lived during the late Ediacaran, and became extinct at the base of the Cambrian.” Categorized with the “small shelly fossils” that preceded the explosion, they can’t have contributed to the Cambrian animal body plans, accordingly (see Chapters 13 and 14 in Debating Darwin’s Doubt). We read on, hoping.
In reefs, we document a periodicity of size variation, where mean, minimum, and maximum tube diameters vary together and show a systematic increase toward the top of each assemblage. We conclude that most Nama Group Cloudina represent one ecologically generalist taxon with highly variable size, that size was environmentally mediated, and that Cloudina could respond rapidly to periodic environmental changes. While Nama Group skeletal metazoans coexisted with soft-bodied biota, there was no apparent ecological interaction, as they were segregated into lithified carbonate and non-lithified clastic microbial mat communities, respectively. We infer that ecological flexibility allowed Cloudina to form varied communities that colonized diverse carbonate substrates under low levels of interspecific substrate competition. This is in notable contrast to the earliest Cambrian skeletal epibenthos that formed biodiverse reef communities with specialist niche occupancy.
So that’s it? Tube diameters increased or decreased according to environmental conditions? If they grew articulated legs, eyes and digestive systems, we might be impressed.
Ho-hum. Evolutionists are not responding to Meyer’s challenge. Looks like a forfeit.
Evolution News | @DiscoveryCSC
When evolutionists deny design, but admit that nature looks designed, they often wind up attributing the skills of a designer to inanimate matter. This is absurd, but what else is available in their explanatory toolkit?
Here’s an example. A headline by Amanda Doyle at NASA’s Astrobiology Magazine reads, “Microbes set the stage for the first animals.” How is this to be understood? Are animals waiting offstage for their debut? Are microbes arranging the props, clearing pathways, and turning on the lights? Surely she cannot mean that. So how can it be understood without personification? Assuming the prior existence of microbes, perhaps she means that their collective behavior resulted in changes in the balances of gases in the atmosphere, or the pH of seawater, or some other unplanned consequence. Does that help?
Doyle focuses on evidence dating from the Ediacaran Period, just prior to the Cambrian explosion. She weaves her plot around the story of a team from the University of Wisconsin-Madison working in Siberia. Photos show their tools beside unusual limestone rocks containing stromatolites and algal impressions. The photos don’t appear to show any Ediacaran creatures themselves. Indeed, those creatures play no role in her play, so they exit stage right: “The remains of these odd creatures, most of which have no evidence of a circulatory or digestive system, largely vanished from the rock record at the start of the Cambrian Period,” she admits [emphasis added], essentially agreeing with the scientists whom Stephen Meyer quotes in Chapter 4 of Darwin’s Doubt.
According to Doyle’s headline, microbes were recruited as the explanatory heroes in her play. Microbes altered the sediments, leaving records of levels of oxygen and sulfur at the time. The UW team found a stratum where “environmental conditions apparently changed,” going from euxinic (sulfidic) conditions that favored microbe growth to oxygenic conditions that would have favored animals.
The change from euxinic to non-euxinic conditions at the end of the Ediacaran Period allowed the Ediacaran animals to colonise the now more oxidized and habitable ocean, despite an overall oxygen level in the atmosphere and oceans that was far less than today’s.
We need go no further. This is a rehash of the Oxygen Theory we have dealt with over and over (for the latest, see here and here). It makes no sense; oxygen has no power to create animal body plans, nor can it “allow” the animals to create themselves. Mr. Oxygen can cry out, “Bring forth! I allow you to evolve!” all he wants on the stage, but nothing will happen. Can’t someone answer the real argument of Darwin’s Doubt, that the abrupt increase in functional information in the Cambrian animals requires a cause that is capable of producing it? The only such cause we know from uniform experience is intelligence. Oxygen has no such power.
We learn at the end of the article that “The research was supported by the Exobiology and Evolutionary Biology element of the NASA Astrobiology Program.” But Darwin’s Doubt came out four years ago, and Debating Darwin’s Doubt two years later. Is NASA really unaware of the challenge?
Let’s keep looking for an explanation that’s new and different. Here’s one: in Science Advances, the open-access journal of the AAAS, a team of six from four American universities spices up the story of the Cambrian.
Several positive carbon isotope excursions in Lower Paleozoic rocks, including the prominent Upper Cambrian Steptoean Positive Carbon Isotope Excursion (SPICE), are thought to reflect intermittent perturbations in the hydrosphere-biosphere system. Models explaining these secular changes are abundant, but the synchronicity and regional variation of the isotope signals are not well understood. Examination of cores across a paleodepth gradient in the Upper Cambrian central Missouri intrashelf basin (United States) reveals a time-transgressive, facies-dependent nature of the SPICE. Although the SPICE event may be a global signal, the manner in which it is recorded in rocks should and does vary as a function of facies and carbonate platform geometry. We call for a paradigm shift to better constrain facies, stratigraphic, and biostratigraphic architecture and to apply these observations to the variability in magnitude, stratigraphic extent, and timing of the SPICE signal, as well as other biogeochemical perturbations, to elucidate the complex processes driving the ocean-carbonate system.
Further reading doesn’t help. The authors know that “The Early Paleozoic era … encompasses an important time frame in metazoan evolution, including the Cambrian Explosion,” but their research only focuses on correlation, not causation. They mention the same “increase in atmospheric oxygen, possibly associated with an oceanic anoxic/euxinic event” that Amanda Doyle focused on.
Conceptual models have been constructed to explain the causes and effects of these sundry secular changes, including ocean anoxia/euxinia driving trilobite turnover, associated enhancement of organic carbon and pyrite burial forcing changes in atmospheric oxygen levels, and oxygenated coastal waters driving the diversification of plankton and perhaps the resulting Ordovician biodiversification.
The changes could well be consequences, not causes, of the Cambrian explosion. And whether the element is oxygen, sulfur, carbon, or anything else, it doesn’t matter. They’re inert. They’re dumb. None of them has creative powers to design new body plans, cell types, and organs, even if they were to “allow” such things to “emerge” onstage.
We’ll try one more. In Geology, the Ediacaran animal Cloudina is mentioned in a paper by seven researchers from Scotland, Russia, and Namibia. Do they describe a sufficient cause for the Cambrian animals?
The Ediacaran skeletal tubular putative metazoan Cloudina occurs globally in carbonate settings, which both provided lithified substrates and minimized the cost of skeletonization. Habitat and substrate preferences and the relationship of Cloudina to other metazoans have not been fully documented, so we know little as to its ecological demands or community dynamics. In situ Cloudina from the Nama Group, Namibia (ca. 550–541 Ma), formed mutually attached reefs composed of successive assemblages in shallow, high-energy environments, and also communities attached to either stromatolites in storm-influenced deep inner-ramp settings or thin microbial mats in lower-energy habitats. Each assemblage shows statistically distinct tube diameter cohorts, but in sum, Cloudina shows an exponential frequency distribution of diameter size.
Meyer doesn’t mention Cloudina, but it’s not much to look at. Visualize a stack of cups forming a tube. The Virtual Fossil Museum says, “The Cloudinids lived during the late Ediacaran, and became extinct at the base of the Cambrian.” Categorized with the “small shelly fossils” that preceded the explosion, they can’t have contributed to the Cambrian animal body plans, accordingly (see Chapters 13 and 14 in Debating Darwin’s Doubt). We read on, hoping.
In reefs, we document a periodicity of size variation, where mean, minimum, and maximum tube diameters vary together and show a systematic increase toward the top of each assemblage. We conclude that most Nama Group Cloudina represent one ecologically generalist taxon with highly variable size, that size was environmentally mediated, and that Cloudina could respond rapidly to periodic environmental changes. While Nama Group skeletal metazoans coexisted with soft-bodied biota, there was no apparent ecological interaction, as they were segregated into lithified carbonate and non-lithified clastic microbial mat communities, respectively. We infer that ecological flexibility allowed Cloudina to form varied communities that colonized diverse carbonate substrates under low levels of interspecific substrate competition. This is in notable contrast to the earliest Cambrian skeletal epibenthos that formed biodiverse reef communities with specialist niche occupancy.
So that’s it? Tube diameters increased or decreased according to environmental conditions? If they grew articulated legs, eyes and digestive systems, we might be impressed.
Ho-hum. Evolutionists are not responding to Meyer’s challenge. Looks like a forfeit.
And still yet more on reality's antiDarwinian Bias
Two Genetic Blows Against Darwinian Speciation
Evolution News | @DiscoveryCSC
Evolution News | @DiscoveryCSC
Classical neo-Darwinism relies on genetic mutations (random mistakes) acted on by natural selection (an aimless effect dependent on what survives). From these two sources of unguided happenstance, all the adapted perfections in life are supposed to have emerged. But what if life is, instead, determined by active information content? An entirely different picture of “evolutionary” change becomes possible: one that involves information sharing. Two recent genomic studies provide additional validation for the new picture.
Insects: Rampant Horizontal Gene Transfer
Horizontal transfer (HT) of genetic information has been well known in microbes for some years now, but recently has been coming more visible in higher organisms. Transposable elements (TE) are, as the name implies, transposable or relocatable within a genome. But could they also play a role in genetic diversity between organisms? Apparently so. A new paper in PNAS announces “Massive horizontal transfer of transposable elements in insects.”
Eukaryotes normally receive their genetic material from their parents but may occasionally, like prokaryotes do, acquire DNA from unrelated organisms through horizontal transfer (HT). In animals and plants, HT mostly concerns transposable elements (TEs), probably because these pieces of DNA can move within genomes. Assessing the impact of HTs on eukaryote evolution and the factors shaping the dynamics of these HTs requires large-scale systematic studies. We have analyzed the genomes from 195 insect species and found that no fewer than 2,248 events of HT of TEs occurred during the last 10 My, particularly between insects that were closely related and geographically close. These results suggest that HT of TEs plays a major role in insect genome evolution.
This is very different from vertical inheritance. How could it happen? It’s like being told you could inadvertently get a piece of DNA from a chimpanzee at the zoo and pass it on to your kids. Impossible. That would scramble every animal’s identity, wouldn’t it? It might explain other people’s kids, but not yours!
The prevalence of HT in higher animals is only now coming to light through systematic studies. These authors examined genomes of “195 insect genomes, representing 123 genera and 13 of the 28 insect orders” to find the 2,248 events they report in the paper. Imagine what this must mean for evolutionary theories of common descent:
We show that DNA transposons transfer horizontally more often than retrotransposons, and unveil phylogenetic relatedness and geographical proximity as major factors facilitating HTT (horizontal transfer of transposons) in insects. Even though our study is restricted to a small fraction of insect biodiversity and to a recent evolutionary timeframe, the TEs we found to be horizontally transferred generated up to 24% (2.08% on average) of all nucleotides of insect genomes. Together, our results establish HTT as a major force shaping insect genome evolution.
The authors recognize that transposons can jump species barriers much easier than genes can. Even so, it’s astonishing to think that this much genetic information could pass readily between species, most likely via bacteria vectors.
In animals and plants, very few cases of such horizontal gene transfers (HGTs) have been reported so far. In fact, most of the genetic material that is horizontally transferred in animals and plants consists of transposable elements (TEs) which are pieces of DNA able to move from a chromosomal locus to another. The greater ability of TEs to move between organisms certainly relates to their intrinsic ability to transpose within genomes, which genes cannot do. HT of TEs (HTT) may allow these elements to enter naive genomes, which they invade by making copies of themselves, and then escape before they become fully silenced by anti-TE defenses.
Some interpretation is required in this kind of analysis. How does one tell HT from vertical inheritance in a stretch of DNA? The authors recognize the challenge, but give four reasons why their numbers are probably low estimates. They conclude, “HTT is not only widespread in insects, but the true number of HTT events is likely to be several orders of magnitude larger than the number we report.” And this is just for recently-diverged insects. Imagine how much transfer goes on worldwide over longer times! At the end of the article, they suggest that more of this is happening than we think, not only in insects, but in other higher eukaryotes:
Extrapolating our estimates over the ∼480 My of insect evolution and the whole insect biodiversity points toward millions of HTT events generating substantial fractions of insect genomes. These inferences, combined with the pronounced impact TEs have on genome structure and dynamics, establish HTT as a major factor driving insect molecular evolution. Our results call for further assessments of the influence of HTT on other taxonomic groups and of the ecological factors and relationships affecting HTT dynamics.
Bears that Care and Share
There’s another means of information sharing: hybridization. Last November we talked about how rampant hybridization is challenging evolutionary theory, weaving Darwin’s tree into a web. Another example just came to light. News from the Senckenberg Research Institute reports widespread gene flow across bears worldwide, leading to the speculation that all bears are interfertile and possibly members of a single species.
Senckenberg scientists have sequenced the entire genomes of four bear species, making it now possible to analyze the evolutionary history of all bears at the genome level. It shows that gene flow, or gene exchange, between species by extensive hybridization, is possible between most bear species – not only polar and brown bear. The DNA samples of different bear species came from different European zoos, underlining their importance not only for conservation, but also for research. The study published today in “Nature Scientific Reports” also questions the existing species concept in general, because other genome studies too have, frequently found gene flow among species.
How could this happen? Hybrids were supposed to be infertile, like the iconic mule. Many hybrids, though, can still bear young, passing on their shared information over generations. The scientists believe that the brown bear may be a “vector species” connecting all species of bears, whether in Asia, Alaska, America, or Europe — by acquiring genes from one region and passing them along between regions as they travel and breed.
As they indicate, this calls into question the very meaning of a species. Dr. Axel Janke wonders, “We have to ask ourselves: Does the species concept still hold true, given there is evidence of gene flow not only in bears, but also in other animals?” This comes close to home with increasing evidence that modern humans have Neanderthal genes. How, then, can we label them with another species label, Homo neanderthalensis? That’s very arbitrary.
Non-Darwinian Implications
In the light of these findings, it seems presumptuous of Darwin to write about “The Origin of Species” when we can’t even say what a species is. But neither would it be correct to think that all plants and animals have fluid boundaries, able to morph endlessly like shape-shifters into anything else. Clearly, you look different from a mushroom. How, then, are we to interpret the living world?
Try information. Notice that both these examples of information sharing are non-Darwinian. They don’t involve accidental mutations and blind natural selection. They are both methods whereby an organism’s genetic information can be given and received. We might consider the way people share good books with one another. That information might cause “change through time” in the way people behave based on what they come to know, but it would not be a blind, unguided process.
In the same way, a designer would give designed organisms the means to adjust to changing environments by the acquisition of pre-existing information, so that they remain what they are but don’t readily go extinct when entering a new habitat or climate regime. Programming for that kind of robustness would make a lot of sense.
On becoming a servant of JEHOVAH:The Watchtower Society's commentary.
How Do I Become One of Jehovah’s Witnesses?
The steps needed to become one of Jehovah’s Witnesses are described by Jesus and can be found at Matthew 28:19, 20. That passage outlines what a person needs to do to become a disciple of Christ, which involves speaking, or bearing witness, about Jehovah.
Step 1: Learn what the Bible teaches. Jesus instructed his followers to “make disciples . . . , teaching them.” (Matthew 28:19, 20) The word translated “disciple” literally means “a learner.” The Bible, especially the teachings of Jesus Christ found there, contains the information you need in order to have a happy and fulfilling life. (2 Timothy 3:16, 17) We are glad to help you learn what the Bible teaches by means of our free Bible study program.—Matthew 10:7, 8; 1 Thessalonians 2:13.
Step 2: Put what you learn into practice. Jesus said that those who learn must also “observe all the things [he] commanded.” (Matthew 28:20) This means that your study of the Bible must be more than an intellectual exercise—it may call on you to make significant changes in your thinking and behavior. (Acts 10:42; Ephesians 4:22-29; Hebrews 10:24, 25) Those who observe Jesus’ commands are then moved to make a personal decision to follow him by dedicating their lives to Jehovah God.—Matthew 16:24.
Step 3: Get baptized. (Matthew 28:19) In the Bible, baptism is compared to a burial. (Compare Romans 6:2-4.) It serves as a symbol of dying to a past course of life and beginning a new one. Your baptism, then, is a public acknowledgment that you have completed the first two steps described by Jesus and are asking God for a clean conscience.—Hebrews 9:14; 1 Peter 3:21.
How will I know if I’m ready for baptism?
Speak to the congregation elders. They will talk with you to ensure that you understand what is involved, are applying what you have learned, and have dedicated yourself to God of your own free will.—Acts 20:28; 1 Peter 5:1-3.
Do these steps apply to children of Witness parents?
Yes. We raise our children “in the discipline and admonition of Jehovah,” just as the Bible commands. (Ephesians 6:4) However, as they grow, they must make a personal decision to learn, accept, and apply what the Bible teaches before they can qualify for baptism. (Romans 12:2) Ultimately, each person must make his own choice concerning worship.—Romans 14:12; Galatians 6:5.
The steps needed to become one of Jehovah’s Witnesses are described by Jesus and can be found at Matthew 28:19, 20. That passage outlines what a person needs to do to become a disciple of Christ, which involves speaking, or bearing witness, about Jehovah.
Step 1: Learn what the Bible teaches. Jesus instructed his followers to “make disciples . . . , teaching them.” (Matthew 28:19, 20) The word translated “disciple” literally means “a learner.” The Bible, especially the teachings of Jesus Christ found there, contains the information you need in order to have a happy and fulfilling life. (2 Timothy 3:16, 17) We are glad to help you learn what the Bible teaches by means of our free Bible study program.—Matthew 10:7, 8; 1 Thessalonians 2:13.
Step 2: Put what you learn into practice. Jesus said that those who learn must also “observe all the things [he] commanded.” (Matthew 28:20) This means that your study of the Bible must be more than an intellectual exercise—it may call on you to make significant changes in your thinking and behavior. (Acts 10:42; Ephesians 4:22-29; Hebrews 10:24, 25) Those who observe Jesus’ commands are then moved to make a personal decision to follow him by dedicating their lives to Jehovah God.—Matthew 16:24.
Step 3: Get baptized. (Matthew 28:19) In the Bible, baptism is compared to a burial. (Compare Romans 6:2-4.) It serves as a symbol of dying to a past course of life and beginning a new one. Your baptism, then, is a public acknowledgment that you have completed the first two steps described by Jesus and are asking God for a clean conscience.—Hebrews 9:14; 1 Peter 3:21.
How will I know if I’m ready for baptism?
Speak to the congregation elders. They will talk with you to ensure that you understand what is involved, are applying what you have learned, and have dedicated yourself to God of your own free will.—Acts 20:28; 1 Peter 5:1-3.
Do these steps apply to children of Witness parents?
Yes. We raise our children “in the discipline and admonition of Jehovah,” just as the Bible commands. (Ephesians 6:4) However, as they grow, they must make a personal decision to learn, accept, and apply what the Bible teaches before they can qualify for baptism. (Romans 12:2) Ultimately, each person must make his own choice concerning worship.—Romans 14:12; Galatians 6:5.
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