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Thursday 8 August 2024

Darwinism is devolving?

 Is This a Paradigm Shift? 


My latest previous post, with David Klinghoffer, was about the “tipping point” in dissent from neo-Darwinism observed by Oxford physiologist Denis Noble, which he pin-pointed as occurring when the Royal Society convened in 2016 for the purpose of rethinking evolutionary theory. From Noble’s viewpoint, since 2016 defenders of neo-Darwinism have gotten very quiet, and young researchers in the emerging generation of scientists are happily working outside the framework of neo-Darwinism. 

Not long ago at all, that sort of change seemed like a distant dream. As Douglas Axe put it in 2016, the academe had become a “self-righteous monoculture,” and I think Axe’s comment expressed how many people felt: “Maybe this regrettable situation will change, someday.”

“Maybe…someday.” Implied was: But don’t hold your breath.

The Zeitgeist is dead.

But that’s always how it feels when a certain climate of opinion is dominant and in line with the current zeitgeist. The dogma seems utterly unshakeable. 

Until, one day, it doesn’t. C. S. Lewis (one of the most vehement critics of the zeitgeist qua zeitgeist) wrote

Nor can a man of my age ever forget how suddenly and completely the idealist philosophy of his youth fell. McTaggart, Green, Bosanquet, Bradley seemed enthroned forever; they went down as suddenly as the Bastille. And the interesting thing is that while I lived under that dynasty I felt various difficulties and objections which I never dared to express. They were so frightfully obvious that I felt sure they must be mere misunderstandings: the great men could not have made such very elementary mistakes as those which my objections implied. But very similar objections — though put, no doubt, far more cogently than I could have put them — were among the criticisms which finally prevailed. 

An idea sits on its glorious throne. None dare question it. All its critics are doomed to perpetual quackdom. And then — just like that! — the zeitgeist changes. Suddenly, that “indisputable” idea is old-fashioned, out-of-date. People forget that they ever believed in it. Another philosophy takes its place, and it seems indisputable.

If Noble is right, that’s happening with neo-Darwinism. And it may be too much to hope, but there is some evidence the shift goes even beyond neo-Darwinism. Even Darwinism itself (without the “neo-”), maybe even the overarching philosophy of methodological naturalism, could be approaching a fall from power. 

For example, Stephen Meyer perceives a shift in the public reception of intelligent design. In 2019, there was already a lot of interest in pro-ID content, but the responses tended to be very vicious. By 2023, the interest was still there, but the reactions seemed overwhelmingly positive. Meyer thinks this is a ripple effect from the deeper change that is underway, as arguments that have been percolating for decades begin to shift opinions in higher intellectual circles.

John West, meanwhile, has noted that opponents of intelligent design seem to be devolving in quality. Follow the downward trajectory from Darwin himself, to Stephen Jay Gould, to Richard Dawkins, to “loudmouth atheist” Jerry Coyne and P. Z. “hammer on the lunatics and idiots” Myers, to the likes of the YouTuber “Professor Dave” … The best of the best in the biology world just don’t seem that invested in attacking intelligent design or defending Darwinism anymore. 

Meanwhile, in the broader philosophical scene, two of the New Atheist “four horsemen of the apocalypse” (Dawkins, Dennett, Hitchens, and Harris) have passed away, and no one seems queued to replace them. Ayaan Hirsi Ali, once a contender for fifth horseman (or first horsewoman?), has converted to Christianity. Dawkins himself recently commented that he doesn’t want to be remembered for being “vehement and an atheist.” 

Something is changing. 

...Long live the Zeitgeist!

But let’s not get too excited. Just because the paradigms are shifting does not mean that intelligent design is going to suddenly take the throne. There are other options. Panpsychism is on the rise. Vitalist theories are coming out of the shadows. Denis Noble’s methodologically naturalist Third Way group are trying hard to carve out a theory of biology that is independent of both neo-Darwinism and intelligent design, placing their hopes in various versions of teleonomy (internal teleology) and autopoiesis (self-construction) as explanations for biological complexity. Whatever emerges victorious from the milieu is likely to be neither intelligent design nor old-fashioned neo-Darwinism — just as whatever emerges from the larger philosophical debates will probably be neither crude materialism nor old-fashioned religious theism. There are other options there, too.

On that note: the lack of will among Dawkins and his sort to fight against ID may be mostly due to the fact that the shifting winds of culture have tossed many of the ID people and Darwinists (including Richard Dawkins and Jerry Coyne) onto the same side of some of the most heated debates. It’s not 2005 anymore, and the center of the “culture war” is no longer between the Religious Right and the New Atheists. Ayaan Hirsi Ali, for her part, has said that one reason she became a Christian was because “secular tools alone can’t equip us for civilizational war.” 

Of course, not all proponents of intelligent design are religious, or politically on any particular side, or interested in civilizational wars. But atheist opponents of ID typically associate ID with religion, so if they find themselves on the same side as religious people in other ideological battles, they are naturally going to have less enthusiasm for attacking ID. 

Get ready for...something.

It isn’t necessarily a positive development. While it’s encouraging that unquestionable tenets of Darwinism are now becoming questionable, and while there are some genuinely encouraging signs of a new openness to the theory intelligent design in many circles, it’s important to realize that the new zeitgeist will not necessarily be any better than the old one. If old enemies are forced to be friends, that could be because they’re having to deal with something worse than either of them.

For example, a power-driven post-truth paradigm could be worse than the old materialist paradigm. Stephen Meyer recently commented that he feels in a sense like a kindred spirit with Richard Dawkins, because both men care intensely about the big questions of life. I saw what Meyer meant when I watched Dawkins’s recent debate with the ex-atheist Ayaan Hirsi Ali. Dawkins brushed aside the critique that the ideas he promoted might have undermined Western civilization with the response that, essentially, that was none of his business: as a scientist, he cared about what was true, consequences be damned. 

It sounded … old-fashioned. And that’s worrisome, because a post-truth paradigm is not likely to yield either truth or good pragmatic outcomes. If a post-truth attitude becomes entrenched in the new paradigm, we might look back nostalgically to the days when materialism was the main intellectual competitor. 

At any rate we don't get a choice.

Whatever the new paradigm looks like, ID theorists are going to want to be at the cutting-edge of engaging with it. Right now, it may be tempting to treat panpsychism, self-construction, teleonomy, and whatever else comes up as frivolous distractions from the real intellectual opponent of Darwinism. But I think that would be a mistake. 

As Denis Noble says, “neo-Darwinism is dead,” or at least dying. In the coming decades, the debate may be between, say, intelligent design and some sort of quantum physics-inflected marriage of scientism and spiritualism, not genuinely materialist, though haunted by the ghost of materialism. Because the coming victor is hard to see before it arrives, ID theorists need to be assessing new theories carefully as they emerge, not relegating them to mockery and dismissal. It would be a mistake to keep beating a dead horseman, and miss what’s coming up from behind. 

Darwinism's supposed simple beginning is truly dead and buried?

 “That Is a Lot of Evolution”: Study Finds LUCA Required 2,600 Genes


Recently I wrote about a study published in Nature Ecology & Evolution which found that the origin of life on Earth “required a surprisingly short interval of geologic time.” But I didn’t mention that the study reported the astounding complexity they inferred must have been present in that life — namely the Last Universal Common Ancestor (LUCA) of all living organisms. In short, they believe that LUCA must have had some 2,600 protein-coding genes — not that much different from many free-living bacteria or archaea that are around today. From the technical paper:

Phylogenetic reconciliation suggests that LUCA had a genome of at least 2.5 Mb (2.49–2.99 Mb), encoding around 2,600 proteins, comparable to modern prokaryotes. … Altogether, our metabolic reconstructions suggest that LUCA was a relatively complex organism, similar to extant Archaea and Bacteria.

“A Fairly Large Genome”

Similarly, a write-up in Science expands on the meaning of the complexity:

The last ancestor shared by all living organisms was a microbe that lived 4.2 billion years ago, had a fairly large genome encoding some 2600 proteins, enjoyed a diet of hydrogen gas and carbon dioxide, and harbored a rudimentary immune system for fighting off viral invaders. 

Likewise a commentary in Nature Ecology & Evolution states

Our results indicate that the LUCA existed between 4.09 and 4.33 billion years ago, a few hundred million years after the moon-forming impact. Our reconstruction of the genome of the LUCA is over 2.5 megabases, comparable to living bacteria, and encompasses at least 2,500 protein-coding genes. The LUCA was capable of nucleotide and protein synthesis, possessed a cellular envelope, and used ATP as an energy currency. … We also found that the LUCA possessed an RNA-based immune system … LUCA must have been part of a broader ecosystem, of which it represents the only living descendant.

Although some aspects of our study are in good agreement with previous work on the LUCA, we infer a larger genome size and genetic repertoire than most previous studies.

This means that not only did life emerge rapidly, but life with a genome composed of thousands of genes and with millions of base pairs emerged rapidly. This is astounding.

Evolutionary Reasoning at Work

Now we must understand that their inferences about LUCA are all based upon evolutionary reasoning. LUCA of course is a hypothetical evolutionary postulate. As such, it depends on universal common ancestry being true. I’m a skeptic of universal common ancestry for various scientific reasons. However, once you understand the reasoning they use to infer the complexity of LUCA, you appreciate the conundrum that this kind of a study poses for naturalistic accounts of the origin of life. An article in the Washington Post invites readers to “Meet the surprisingly complex ancestor of all life on Earth.” It explains the methods that were used:

The new timeline and details can be chalked up to more advanced analysis methods available today. In the new study, the team of 19 scientists used a combination of genetic analysis and fossil records to determine the age of LUCA and its characteristics. They first compared genes in modern genomes of bacteria and archaea to determine which gene families were present in LUCA. They estimated LUCA’s genome size, the number of proteins it encoded and its metabolism.

In other words, by comparing the genomes of modern organisms, they were able to infer the minimal sets of genes that must have been present if in fact they are all descended from a common ancestor. The bottom line? It’s a lot of genes — making LUCA more complex than many evolutionary theorists probably expected to find. As the Washington Post noted:

In the most extensive analysis of the organism to date, scientists propose in a new study that this hypothesized ancestor was more sophisticated than previously known — thought to possess an immune system to fight off viruses, for instance.
The team said LUCA appeared around 4.2 billion years ago, shortly after Earth was thought to be habitable, suggesting it evolved even quicker than previous estimates and survived through tumultuous times on the planet.
[…]But LUCA may have been more complex than they previously thought, the authors found. They inferred it had an immune system that fought viruses and found evidence suggesting it contained genes to protect against ultraviolet damage and lived at the ocean surface.

The lead author of the study was quoted as saying, “[T]his was a fairly complex organism, already possibly by the time of like 4.2 billion years ago.” Another scientist commented, “LUCA was a very complex cell, with a genome similar to modern bacteria (which we think of as simple, but from a molecular biology perspective are very complex).”

That latter scientist was further quoted saying: “That is a lot of evolution to happen within 100 million years or less.” A lot of evolution, indeed.

An Unanswered Question

This leaves unaddressed the question of whether organismal life, a “very complex cell,” could exist at all below the threshold of complexity that the study attributes to LUCA — without, for example, sophisticated defenses such as an “immune system that fought viruses” or “genes to protect against ultraviolet damage.” 

Would a much simpler cell be viable? To think so pushes the envelope of plausibility. If it would be viable, someone needs to explain how such a defenseless life could survive to reproduce. If it wouldn’t, the strong suggestion is of life springing from non-life without a far simpler yet viable transitional state. 

Transitions like that, including very rapid ones, are a hallmark of human-devised technology. In the context of the early Earth, it sounds like the act of a creative agent, existing before the first cell came to be. In other words, it sounds like intelligent design.


Wednesday 7 August 2024

For the defence

     An unabridged excerpt of Bill davidson's article in the Nov.2nd 1946 edition of Collier's Entitled:Jehovah's travelling salesmen:P.75  


"because of the obviously huge income from the millions of publications every year the board of directors have often been accused of using Jehovah's Witnesses as a personal racket. 


There is no evidence to support these charges.The leaders actually live in lower middle class simplicity,and the first president of the Society,Charles Taze Russel,left exactly $200 in his will when he died in 1916.He had been the owner of a chain of haberdashery stores and a very wealthy man at one time.The same thing is true of Judge Joseph F.Rutherford,the second president.A few years ago,Roger baldwin of the American civil liberties union became one of the few men outside of the board of directors to get some official notion of the organisations finances.Baldwin is convinced that the million dollar profit of that particular year was almost completely eaten up by foreign publication losses,administration expenses and the tremendous legal expenses necessary to defend the witnesses in courtrooms."


Page 4 paragraph 1 Watchtower society's charter."It does not contemplate pecuniary gain or profit,incidentally or otherwise,to its members,directors or officers.Its members shall be only men who are mature,active and faithful witnesses of Jehovah devoting full time to performance of one or more of its chartered purposes under its direction and by its authority,or such men who are devoting part time as active presiding ministers or servants of congregations of Jehovah's witnesses."



Master race delusions are a necessary implication of Darwinism?

 West, Metaxas: Face It, Darwinian Theory Is Itself Racist


Let’s be candid. It’s not just that Darwinian theory has had racists among its proponents. The theory itself is racist, with many evil stains on its conscience that follow straight from that fact, as any honest evolutionist would have to admit. You could cite the writing of Darwin himself, the disturbing illustrations of human evolution offered by his German disciple Ernst Haeckel, the “human zoos” of the early-20th-century United States, leading right up to the theory’s complicity in justifying the Final Solution.

But it’s more than that. As John West and Eric Metaxas emphasize in a new Socrates in the Studio episode, this malign record is no mere inexplicable aberration from an otherwise innocent scientific theory. The legacy is not a mistake, or a byproduct of the unenlightened past. It is quite explicable. It follows logically from Darwinian thinking itself, especially as reflected in The Descent of Man. 

A Straightforward Reading

As Dr. West notes, a straightforward reading of that book indicates “you should expect dramatic differences” among races. After all, natural selection operates differently in different environments — say, in Africa as opposed to Scandinavia. It’s an inevitable prediction of evolution (very different from Judeo-Christian tradition, or from intelligent design) that the human races would be unequal. And given that, why wouldn’t you also expect that one race is closest of all to our ape cousins? What would be surprising is if there weren’t such a race. Darwin and the Darwinists saw that clearly, and the notorious human zoos at the St. Louis World’s Fair (see the photo at the top) and the Bronx Zoo, in 1904 and 1906 respectively, were simply seeking to educate the public about the implications of evolutionary biology.

Watch the episode here, though you will need to subscribe to Socrates + to continue beyond the first half hour or so. At about that mark, Metaxas asks a very good question: Today’s evolutionists (or most of them, beyond those on the demented far right) dismiss racist views. But in keeping with their Darwinism, how can they do this? What is their rationale? Do they have one that makes any sense?

Metaxas mentions that he’s familiar with how Hitler’s Nazis applied an evolutionary lens in their ideology. He covers that in his book Bonhoeffer, which I’m reading now — and it is excellent. For still more background, watch John West’s awarding-winning Documentary Human Zoos. It’s an in-depth look at this disturbing and typically covered-up thread from the history of “consensus science”:


Sunday 4 August 2024

Yet another house divided?

 

Primeval tech continues to corrode the Darwinian narrative?

 Review Article Explores Design Patterns in Biological Cells


An excellent review article, “Design Patterns of Biological Cells,” published earlier this year in BioEssays, shows that design patterns are “generalized solutions to recurring problems.” (Andrews, Wiley, and Sauro 2024) The theory of intelligent design (ID), which suggests that certain aspects of nature are better explained by intelligent agency than by law-like regularities and chance events, predicts design patterns in nature. This is because design patterns are technically derived solutions — derived by designers — to challenges encountered within the design space.

The authors review three types of design patterns. For each, I’ll pick one subcategory and flesh it out in a bit more detail. I will then turn to discussing how each design pattern requires direct actions of an intelligent agent. Here are the three categories:

“Creational” describes recurring patterns for building components of the cell.
“Structural” describes interconnections or relationships between objects in the cell.
“Behavioral” describes the behavior of cellular objects through time.

Creational Design Patterns

Andrews et al. identify five subcategories for creational design patterns. The first of these subcategories is templating. Cells need to maintain the information in DNA and prevent it from being corrupted by time and chance. The solution to this problem is templating where the original information is faithfully templated or copied. Templating in the cell includes DNA replication, transcription, and translation. Templating points to an intelligent agent behind its design because it requires comprehension of the forces imposed by the laws of physics and chemistry that would need to be overcome to preserve information. Templating also requires foresight to imagine a solution, inventing irreducibly complex molecular machines like DNA polymerase, RNA polymerase, and the ribosome. Finally, templating requires creation of the information itself, the physical DNA code for the polymerases and ribosome

Structural Design Patterns

Structural patterns are design patterns based on object-to-object relationships. For structural patterns, Andrews et al. identify six subcategories. Of these, the third is common currency.

Across cells, there are many common metabolites, including common storage forms of energy, such as ATP. Traditionally, this has been attributed to common ancestry, but there is a critical design-based reason for it. Using a common currency simplifies interactions between objects. For example, it’s easier to fill up your car with gasoline when gasoline is a common currency because no matter where you travel, other people need gasoline for their cars, and so chances are you will find it for sale. Here’s another example: It is easier to buy groceries with a common currency, such as the U.S. dollar, because you don’t have to stop and exchange your money before making a purchase, likely paying a fee for doing so. 

Cells face similar constraints. They rely on certain producers of energy at certain times and incur a cost for energy interconversions. Thus, ATP is likely a designed solution to the aforementioned requirements. Andrews et al. point out that the topological pattern of common currency has a “bow tie” architecture. In this type of architecture, many nutrients are turned into a common currency (the knot) which can then expand to accomplish many different things. This design motif requires an intelligent agent because the goals of the ecosystem and organisms must be evaluated before coming up with a currency that can work between lower-level objects. This entails an understanding of how everything will interrelate and what is possible in the design space of physics and chemistry, followed by planning and implementation. Only an intelligent agent has these capabilities, which are not accessible to random processes.

Behavioral Design Patterns

Behavioral design patterns focus on the dynamics of reaction networks. Andrews et al. identify eight such patterns. For example, there is switching, which occurs when a continuum of input needs to be converted into a discrete output. The most common ways of accomplishing this are by using ultrasensitivity or bistability. Ultrasensitive switches facilitate a sharp threshold response, ensuring that the system is fully in one state or the other, rather than in an intermediate state. This can be accomplished in different ways. A classic example of ultrasensitivity in biology is the necessary switch of hemoglobin from binding oxygen in the lungs to releasing it in the muscles. This is performed through the allosteric design of hemoglobin. When the partial pressure of oxygen is high (in the lungs), binding of one molecule of oxygen makes binding of the next oxygen molecule easier. Importantly, when one plots the percentage of hemoglobin bound to oxygen versus the partial pressure of oxygen, the curve is sigmoidal, not hyperbolic. The sigmoidal shape tells us that in the lungs, binding of oxygen is easier after the first molecule binds and release of oxygen becomes easier in the muscle after the first molecule is let go.

Ultrasensitivity, represented by that sigmoidal curve, can be accomplished in another way. Suppose there is a phosphorylation-dephosphorylation cycle where the kinase and phosphatase are working at saturation levels and have rate constants that are independent of the concentration of their substrates. Although it isn’t abundantly clear until this is plotted graphically, the response is also ultrasensitive, i.e., sigmoidal. Given those conditions, the cycle can switch sharply between being almost entirely in one state to being almost entirely in the other state. (Ferrell and Ha 2014b)

Another way ultrasensitivity works is by having multiple phosphorylation sites on a kinase where the kinase isn’t active until the final phosphorylation, and each successive phosphorylation is a little bit easier than the prior one. (Ferrell and Ha 2014a)

Yet another example is concentration-based inhibition. Here, a tightly bound inhibitor might prevent enzyme activity, up until the enzyme concentration surpasses that of the inhibitor. At that point the enzyme is no longer inhibited, leading to a sudden switch.

A final and somewhat different example is positive feedback. This occurs more frequently in developmental networks than in sensory networks. Why is that the case? Positive feedback slows response time, which is advantageous for multistage processes that are time-consuming or include delays. Slower response times can also help reduce noise, which is critical when making irreversible decisions. However, positive regulation can accomplish more than just that. Positive regulation can make sharp decisions between two states and remembering those decisions for a long time, a phenomenon known as bistability. Consider positive feedback in gene regulation: once a gene is activated by positive autoregulation, it is locked ON. The gene will remain elevated even after the input has disappeared, providing long-term memory that the input existed. This type of switching is employed during development to make irreversible decisions that commit a cell to a specific fate. (Alon 2019)

Why does the switching design motif point to intelligence? Designing an effective switch requires understanding the system and what needs to be controlled “— what needs to be turned on or off at what time?” Considering whether control should be manual or automated is needed. Additionally, building appropriate switches requires knowledge about safety. Switching is also often necessary in sequential operations. The type of switch, the sensitivity of the switch, the construction of the switch, and the switch’s compatibility must all be thought through ahead of time. Each switch functions a certain way in the system such that it appears to “know” or “anticipate” other switch behavior so that more complex behavior can be produced.

Why Study These Design Patterns? 

It is useful to compile a list of solutions that cells utilize to solve specific problems. Design patterns abstract a broad range of cell functions into a manageable set of distinct patterns connected to the functions they serve by showing how they solve certain problems. Looking at these, as we did with the example of the different ways ultrasensitivity is currently known to be accomplished, provides a deeper understanding of why cellular mechanisms operate the way that they do. Accordingly, design patterns in cells also provide an outstanding illustration of how design-based thinking can further our understanding of biology.

References

Alon, Uri. 2019. An Introduction to Systems Biology: Design Principles of Biological Circuits. Second edition. | Boca Raton, Fla. : CRC Press, [2019]: Chapman and Hall/CRC.
Andrews, Steven S., H. Steven Wiley, and Herbert M. Sauro. 2024. “Design Patterns of Biological Cells.” BioEssays: News and Reviews in Molecular, Cellular and Developmental Biology 46 (3): e2300188.
Ferrell, James E., Jr, and Sang Hoon Ha. 2014a. “Ultrasensitivity Part II: Multisite Phosphorylation, Stoichiometric Inhibitors, and Positive Feedback.” Trends in Biochemical Sciences 39 (11): 556–69.
Ferrell, J. E., Jr, & Ha, S. H. (2014b). “Ultrasensitivity Part I: Michaelian Responses and Zero-Order Ultrasensitivity.” Trends in Biochemical Sciences 39 (10): 496–503.

Saturday 3 August 2024

Against nincsnevem ad pluribus XXI

 Mr. Nevem claims that there is some setting preventing him from commenting on my channel,I find it quite odd that he seems to be the only person who has been affected by this supposed setting. My channel setting simply says that anyone with a Google ID can comment. Google of course is the parent company of the blogspot platform,anyone can obtain a Google ID for free in literally a matter of minutes. So I'm sorry nincs but this leaves you looking quite weak.

Timing is everything?

 

On the origin of the Lizard King.

 Fossil Friday: Controversial Gradualism in Tyrannosaurids


This Fossil Friday features the tyrannosaurid Daspletosaurus torosus from the Late Cretaceous of Canada. This dinosaur genus was recently in the news (News Release 2024) and caused a flurry of tweets (see Fowler 2024 on X) because of a scientific controversy about the origin of the famous T. rex — either by gradual transformation of Daspletosaurus into Tyrannosaurus, or by more discontinuous splitting from the daspletosaurine lineage. The former process of speciation is called anagenesis and the latter cladogenesis. Anagenesis is a special case of Darwinian gradualism, which is largely contradicted by the evidence from the fossil record, as I have discussed in several previous articles (Bechly 2019, 2024a, 2024b). Dinosaur paleontologists Elías Warshaw and Denver Fowler nicknamed their preferred view of an anagenetic origin of the genus Tyrannosaurus from Daspletosaurus the “Tyrannagenesis hypothesis” (Fowler 2024 on X).

Anagenesis as a mechanism of speciation in Daspletosaurus was already proposed by Carr et al. (2017) for the transition between Daspletosaurus torosus and the younger new species Daspletosaurus horneri from the Late Cretaceous of Montana. This latter species was named after famous dinosaur paleontologist Jack Horner, who had first suggested phyletic evolution in four lineages of dinosaurs including tyrannosaurids (Horner et al. 1992). A few years later, Warshaw & Fowler (2022) described another species of Daspletosaurus, and suggested that the three known species of this genus formed an evolutionary transition towards Tyrannosaurus (and the closely related genera Tarbosaurus and Zhuchengtyrannus), which would imply that the genus Daspletosaurus is not a distinct clade but a paraphyletic grade. This was communicated by the popular science media with headlines like “Newly-Discovered Tyrannosaur Species Fills Gap in Lineage Leading to Tyrannosaurus rex” (Anderson 2022). Darwin was proven right again, right? Right?

Well, Not So Fast

This year a new study by Scherer & Voiculescu-Holvad (2024) challenged the whole story. Their reanalysis of the dataset of their colleagues Warshaw & Fowler (2022) decisively refuted those claims of anagenesis in the tyrannosaur lineage. They concluded that “the dataset reveals that anagenesis is not found to be a driver of speciation within Daspletosaurus.” Instead they found strong evidence for “cladogenetic Tyrannosauridae composed of four morphologically and biogeographically distinct clades.” In their reconstructed phylogenetic tree, the three distinct species of Daspletosaurus formed a clade with the genus Thanatotheristes as sister group to a clade that includes Zhuchengtyrannus, Tarbosaurus, and Tyrannosaurus. The scientists explicitly cautioned that “all known species of Daspletosaurus do not meet previously established prerequisites for anagenesis and advise against prematurity when making conclusions concerning significant processes surrounding the mode of evolution of extinct genera with sparse and often incomplete fossil records.”

This unsurprisingly provoked a quick response by Warshaw et al. (2024), which is still in pre-proof stage, in which they present an updated analysis, incorporating further data and corrected “erroneous” interpretations, which allegedly overturns this challenge and again supports anagenesis in the tyrannosaur lineage.

A Striking Admission

History will tell who is right in this scientific controversy, but personally I am more convinced by the evidence against anagenesis. Therefore, I can only reiterate what I had already emphasized in my earlier article (Bechly 2019):

On the occasion of the Darwin Year in 2009, Hunt (2010) had reviewed all the fossil evidence for species transitions assembled by paleontologists in 150 years of research since the time of Charles Darwin. Hunt’s conclusion was mind blowing, even if framed in somewhat obfuscating language:

The meandering and fluctuating trajectories captured in the fossil record are not inconsistent with the centrality of natural selection as an evolutionary mechanism, but they probably would not have been predicted without the benefit of an empirical fossil record.

Apart from the obligatory verbal kowtow to Darwinian orthodoxy, this striking admission simply means that the empirical data from the fossil record strongly contradict the gradualist predictions of Darwin’s theory. There hardly exists any fossil evidence for directional and gradual species-to-species transitions, and especially not for anagenesis.

References

Anderson N 2022. Newly-Discovered Tyrannosaur Species Fills Gap in Lineage Leading to Tyrannosaurus rex. SciNews November 25, 2022. https://www.sci.news/paleontology/daspletosaurus-wilsoni-11424.html
Bechly G 2019. Apeman Waves Goodbye to Darwinian Gradualism. Evolution News September 6, 2019. https://evolutionnews.org/2019/09/apeman-waves-goodbye-to-darwinian-gradualism/
Bechly G 2024a. Fossil Friday: Chronospecies, a Sinking Ship. Evolution News February 9, 2024. https://evolutionnews.org/2024/02/fossil-friday-chronospecies-a-sinking-ship/
Bechly G 2024b. Fossil Friday: Direct Fossil Ancestors of Living Species? Evolution News March 8, 2024. https://evolutionnews.org/2024/03/fossil-friday-direct-fossil-ancestors-of-living-species/
Carr TD, Varricchio DJ, Sedlmayr JC, Roberts EM & Moore JR 2017. A new tyrannosaur with evidence for anagenesis and crocodile-like facial sensory system. Scientific Reports 7:44942, 1–11. DOI: https://doi.org/10.1038/srep44942
Horner JR, Varricchio DJ & Goodwin MB 1992. Marine transgressions and the evolution of Cretaceous dinosaurs. Nature 358, 59–61. DOI: https://doi.org/10.1038/358059a0
Hunt G 2010. Evolution in Fossil Lineages: Paleontology and The Origin of Species. The American Naturalist 176(S1), S61–S76; DOI: https://doi.org/10.1086/657057
News Release 2024. New research by Badlands Dinosaur Museum Paleontologists sheds light on the ancestry of Tyrannosaurus rex. Dickinson Museum Center June 29, 2024. https://www.dickinsongov.com/museum-center/page/anagenesis-and-tyrant-pedigree
Scherer CR & Voiculescu-Holvad C 2024. Re-analysis of a dataset refutes claims of anagenesis within Tyrannosaurus-line tyrannosaurines (Theropoda, Tyrannosauridae). Cretaceous Research 155: 105780, 1–9. DOI: https://doi.org/10.1016/j.cretres.2023.105780
Warshaw EA & Fowler DW 2022. A transitional species of Daspletosaurus Russell, 1970 from the Judith River Formation of eastern Montana. PeerJ 10:e14461, 1–29. DOI: https://doi.org/10.7717/peerj.14461
Warshaw EA, Barrera Guevara D & Fowler DW 2024. Anagenesis and the tyrant pedigree: a response to “Re-analysis of a dataset refutes claims of anagenesis within Tyrannosaurus-line tyrannosaurines (Theropoda, Tyrannosauridae)”. Cretaceous Research 105957 pre-proof. DOI: https://doi.org/10.1016/j.cretres.2024.105957

Friday 2 August 2024

Continuing to distinguish between science and science.

 

Fish hearing vs. Darwin.

 Study Unravels the Mystery of Fish Hearing


A newly published study in the journal Nature concerning fish hearing has apparently unraveled the mechanism for how they determine the direction of sound.1 For a long time it was believed that fish did not possess any sense of hearing. One reason was because they do not have external ears. That ignored the fact that hearing is accomplished by the inner ear in most animals. It was Nobel Prize-winner Karl von Frisch who conducted experiments in the 1930s that proved fish can hear sounds. Since then, it has been known that fish can determine the direction of sounds. Yet an explanation of how this is accomplished has been elusive. 

Human Hearing

It is instructive first to understand how humans and other vertebrate animals determine the direction of sound. Humans use the time difference between the arrival of sound waves at the two ears. This is called the interaural time difference (ITD). Humans can discern the horizontal direction to within 2 degrees, which translates to a time difference of 11 microseconds.2 That means human brains have an extremely well-designed neural network to achieve that level of performance. One theory is that there is a network of neurons that “use axons as delay lines and to measure small time differences precisely.”3 In addition, vertebrates detect the differences in sound wave pressure between the ears, which is also an aid in determining direction.

Challenge of Sound Detection Underwater

Detecting and processing sound underwater presents more problems than in the air. One is that the speed of sound is approximately five times faster in water than in air. That means that the ITD is significantly shorter, which makes it more challenging to measure the difference in the arrival time between two receptors in an animal. The detected pressure differences are also smaller underwater. In addition, sound pressure in water has no directional component. Due to these and other technical problems the prevailing models indicated that it should not be possible for fish to determine the direction of a source of sound. 

Evidence of Fish Detection of Sound Direction

There is a large body of experimental evidence showing that fish can determine the direction of sound. Directional hearing is essential to a number of fish behaviors, including finding prey, avoiding predators, and locating mates. The ability to move in the direction of the source of sound is called phonotaxis. One example in fish is that the females of some species will seek the mating call of males. That includes the ability to distinguish different species, as fish bioacoustics scientists Anthony Hawkins and Arthur Popper explain, “Behavioral studies of sound communication have indicated that fish discriminate between calls on the basis of differences in repetition rate and duration, rather than frequency or bandwidth.”4 It should not be surprising that fish have very good hearing capabilities because as Jonathan Balcombe, author of What a Fish Knows, writes, “Despite the common assumption that fishes are silent, they actually have more ways of producing sounds than any other group of vertebrate animals…Fishes produce a veritable symphony of sounds…So notable are the sounds of some fishes that we have named the fishes accordingly: grunts, drums, trumpeters, croakers, sea robins, and grunters.”5

Experiments were conducted in which Atlantic cod and haddock were conditioned to respond to a pulsed tone from loudspeakers at different horizontal angles. The results showed that the fish readily detected the difference when the loudspeakers were separated by 20 degrees or more.6 Hawkins and Popper also state that the experiments “demonstrated that the cod is well able to discriminate between separate sound sources in 3D space.”7 There is evidence in mammals for a correlation between the field of vision and the ability to determine the direction of sound.8 In other words, the narrower the field of vision the more accurate the sound localization that appears to be required. In the case of fish, since they typically have a very wide field of vision, their localization of sound probably does not need to be that accurate. Hence, as was found in the described experiment, localization within about 20 degrees is likely sufficient. The fact that fish have the ability to determine the direction of sound and employ it in numerous behaviors made it all the more confounding why scientists had been unable to determine the mechanism.

One important characteristic of fish that does help sound detection is that they are acoustically transparent. This characteristic is useful because, in addition to pressure, the transmission of sound in any medium occurs through the oscillation of pressure and motion. In addition to the oscillatory change of the pressure wave, underwater sound also consists of a to-and-fro motion of particles in the direction of transmission. This phenomenon is called particle motion which “can be measured in terms of displacement, velocity, or acceleration, (and) differs from the sound pressure in that it is inherently directional, and all the motion parameters are vector quantities.”9 It turns out that this phenomenon of sound transmission in water is crucial as, “This mechanism for the direct detection of particle motion by the otolith organs is found in all fishes.”10Detection of this motion isn’t trivial since, “The to-and-fro displacements of the very small body of water are of the order of nanometers.”11 At first it might seem simple to determine direction based on particle motion since the motion is directly in line with the propagation of the sound wave. The problem, however, is that because the motion is back-and-forth, there is an ambiguity of 180 degrees in the direction.

The Experiment

For the experiment documented in the Nature paper the researchers tested hearing capability in Danionella cerebrum, one of the smallest teleost (bony) fish. An additional problem for hearing in small fish is that the distance between the inner ears is relatively short. In the case of D. cerebrum it is only about 0.6 millimeters, which is several orders of magnitude smaller than the wavelength of sound (approximately 150 millimeters). That makes it difficult to measure the phase of the detected pressure wave. The experiment was able to simulate and control a number of variables associated with sound (notably pressure and motion) and observed how the fish reacted. In addition, during the experiment a laser scanning microscope was used to examine the fish hearing auditory structures. This enabled the researchers to compare the reaction of the auditory structures with the various models.

Directional Hearing Mechanism

The study evaluated several different theories and models of potential mechanisms for determining direction. After the researchers compared the experimental results with the models, the evidence provided the most validation for one model, originally proposed by zoologist Arie Schuijf in 1975. The Schuijf model is based on the comparison of pressure and particle motion. Fish are able to detect the motion of pressure and particle motion separately, using individual detectors. The detection of pressure occurs in the swim bladder as, “All known sound pressure sensors in fish are based on compressible gas-filled organs.”12 The swim bladder is the organ used by bony fish to control their buoyancy. Particle motion can be detected because, being acoustically transparent, tissue in the fish is coupled to the motion of the water as it moves through the fish. The two measurements can then be compared and used to estimate the incoming direction of sound. The reason this is possible is because the pressure and particle motion are out of phase. When pressure is highest the particle motion is away from the source. When pressure is lowest the particle motion is toward the source.

As described by the authors of the paper, this physical characteristic of underwater acoustics provides the basis for the directional hearing algorithm. There is a neural mechanism that uses these two sensory inputs to estimate the direction that the sound is coming from. In addition to highly sensitive sensors it must also include an accurate internal clock to determine when the two inputs are to be compared. The fish directional hearing algorithm appears to be another example of a complex programmed behavior in animals.13 However, as indicated in a related Nature article, “We do not yet know what happens in the brain and how it interprets information from the inner ear about the phase and amplitude of sounds.”14

Some experiments also appear to indicate that fishes can estimate distance based on the information provided by pressure and particle motion sensors. The ability to estimate the distance of the source of sound is a hearing capability not possessed by humans. Some species of fish can detect ultrasound up to frequencies of 180,000 Hertz.15 Human hearing capability is typically up to 20,000 Hertz. Very impressive capabilities for animals that scientists once thought had no hearing ability at all!

Notes

Veith, et al., “The mechanism for directional hearing in fish,” Nature, Vol. 631, 4 July 2024, 118-23.
Mark F. Bear, Barry W. Connors, Michael A. Paradiso, Neuroscience (Philadelphia: Lippincott Williams & Wilkins, 2007), 369.
Bear, et al., Neuroscience, 370.
Anthony D. Hawkins, Arthur N. Popper, “Directional hearing and sound source localization by fishes,” J. Acoust. Soc. Am. 144, 3329-3350, December 14, 2018.
Jonathan Balcombe. What a Fish Knows (New York: Scientific American, 2016), 40-41.
Hawkins and Popper, “Directional hearing and sound source localization by fishes.”
Hawkins and Popper, “Directional hearing and sound source localization by fishes.”
Henry E. Heffner, Rickye S. Heffner, “The evolution of mammalian hearing,” AIP Conf. Proc. 1965, 130001, May 31, 2018.
Popper, et al., “Examining the Hearing Abilities of Fishes,” J. Acoust. Soc. Am., 146, 948–955 (2019).
Popper and Hawkins, “The importance of particle motion to fishes and invertebrates.”
Arthur N. Popper, Anthony D. Hawkins, “The importance of particle motion to fishes and invertebrates,” J. Acoust. Soc. Am. 143, 470-488, January 29, 2018.
Veith, et al., “The mechanism for directional hearing in fish,” 123.
Eric Cassell, Animal Algorithms (Seattle: Discovery Institute Press, 2021).
Catherine E. Carr, “How fish sense the direction of sound,” Nature, Vol. 631, 4 July 2024, 29.
Friedrich Ladich and Tanja Schulz-Mirbach, “Diversity in Fish Auditory Systems: One of the Riddles of Sensory Biology,” Front. Ecol. Evol. 4:28, 31 March 2016.

Thursday 1 August 2024

Against nincsnevem ad pluribus XX.

 Nincs:Mary and the Second Eve

The argument that Mary would have recognized Jesus as the Second Adam if she were truly the Second Eve misunderstands both the role of typology and Mary’s faith journey. Mary’s understanding of her Son’s mission grew over time, just as the apostles’ understanding of Jesus' messianic role developed gradually. Her initial responses, including her participation in the purification rite and her concern for Jesus' well-being, reflect her humanity and deep maternal love, not a lack of understanding of Jesus' identity.

Moreover, being the Second Eve does not imply immediate and complete knowledge of all theological implications. It indicates Mary’s unique role in salvation history as the one who, through her obedience, reversed the disobedience of Eve. Mary’s sinlessness is rooted in her unique role in God’s plan of salvation, which is why the Church venerates her as the sinless Mother of God.

Failure to acknowledge JEHOVAH'S Prophet is a sin.

John ch.8:24NIV"I told you that you would die in your sins; if you do not believe that I am he, you will indeed die in your sins.”

John ch 15:24NIV"If I had not done among them the works no one else did, they would not be guilty of sin. As it is, they have seen, and yet they have hated both me and my Father."

Mary obviously repented of her lapse into faithlessness but that is different from claiming that she was born like Eve free from inherited sin.

By way of a reminder 

Mark ch.3:21NIV"When his family heard about this, they went to take charge of him, for they said, “He is out of his mind.”

Verse 33 indicates that Jesus Mother was numbered among those not heeding the meaning of the many powerful signs JEHOVAH Was performing through Him for a time,this would have been something she would need to repent of and seek forgiveness for which she evidently did,

Against nincsnevem ad pluribus XIX

Nincs: Jesus’ Words About His Family (Matthew 12:49-50)

The passage where Jesus speaks about His disciples as His mother and brothers is often misunderstood. Jesus is not rejecting or diminishing Mary’s role; rather, He is expanding the concept of family to include all who do the will of God. This does not contradict the veneration of Mary but highlights that spiritual kinship is based on obedience to God. Mary, as the first and most perfect disciple of Jesus, who fully did the will of God, is the ultimate model of this spiritual family. Far from being an "odd" thing to say, Jesus’ words emphasize the importance of spiritual relationships in the Kingdom of 

Me:Again what I Said was that if Jesus wanted his mother to be venerated as the only other sinless woman who ever lived Besides Eve and coredemptrix and queen of heaven, this statement putting her on the the same level as any other sinful believer seems odd the Bible makes Jesus separation from sinners and his roles as the perfect priest and prophet quite clear .

Matthew ch 12:48-50NKJV"But He answered and said to the one who told Him, “Who is My mother and who are My brothers?” 49And He stretched out His hand toward His disciples and said, “Here are My mother and My brothers! 50For whoever does the will of My Father in heaven is My brother and sister and mother"

Not only that after his glorification he made no declarations through her at all preferring to use sinful men as teachers when he had a perfect sinless woman in their midst quite puzzling.

Against nincsnevem ad pluribus XVIII

 Nincs:The Law and Inherited Sin

The claim that the law only applies to those with inherited sin and thus would not apply to Mary if she were sinless misunderstands the nature of the Mosaic Law. The law was a comprehensive system that applied to all Israelites, regardless of individual sinfulness. Jesus Himself, who was without sin, was circumcised (Luke 2:21) and participated in other rites prescribed by the law. His submission to the law was not an indication of sin but a demonstration of obedience to God's commandments. Similarly, Mary's participation in the purification rite (Luke 2:22-24) was an act of obedience and humility, not an indication of sin.

Me:as tends to be the case I have to give my actual position in lieu of Mr.nevem's strawman,what I Said was that sin offerings would only apply to those conscious of sins, offerings made for the sins of the nation as a whole would be one thing but the law is clear a personal sin offering would only be made by one who has committed sins,this can be seen by the fact that confession of ones sins were involved in the ritual.

See leviticus 5


Moreover, the law’s purpose was not solely to address personal sin but to regulate the covenantal relationship between God and His people. Mary, being fully Jewish and living under the Mosaic Law, would naturally observe its requirements, even if she was preserved from original sin. This does not negate her sinlessness but shows her faithful adherence to the la

Me:The offering of whole burnt offerings would not be necessary for someone who is not conscious of sin under the law if a person kept the moral requirements of the law no sin offering would be necessary from such a person the constant offering whole burnt offerings demonstrated the ineffectiveness of the law that is why Christ could say something greater than the temple is here,

Hebrews ch.9:12NIV"He did not enter by means of the blood of goats and calves; but he entered the Most Holy Place once for all by his own blood, thus obtaining eternal redemption."


Against nincsnevem ad pluribus XVII.

 

Nincs:Your argument appears to misunderstand both the nature of God’s foreknowledge and the theological position held by many Christian traditions regarding free will and predestination.

Me:My argument is that if God has foreknown the infinite future exhaustively From the infinite past the only LOGICAL conclusion is that the infinite future has been foredetermined from the infinite past, and that if JEHOVAH is the true first and sole cause of this exhaustively foredetermined universal creation it is he who has either actively or passively exhaustively foredetermined the future, so before JEHOVAH Creates the unrepentant murderer he knows from the infinite past that he will murder unrepentantly, of course this event is foredetermined nothing else but this can happen. but the only way it can happen is if JEHOVAH CHOOSES to give the remorseless murderer a body and a mind and access to the weapons and knowledge the remorseless murderer would need to commit his crime . JEHOVAH Can choose to deny the remorseless murderer what he needs to commit his crime, he chose otherwise.

Either JEHOVAH is incapable of creating our hypothetical remorseless murderer in a way that gives him a genuine moral choice . Or he can create him with a genuine choice re: his moral development and chose not to. So this is about basic logic . As you will see Mr.nincsnevem responds in typical fashion not by demonstrating any inconsistency in my logic but by parotting the party line in his typically circular style of argumentation. 



Nincs:Firstly, it’s important to clarify that God’s foreknowledge and human foreknowledge are indeed different, but this does not negate the possibility of God knowing the future without determining it. Christian theology traditionally teaches that God, being outside of time, sees all events—past, present, and future—simultaneously. This does not mean that God determines every action that will occur; rather, it means that God knows the choices that free creatures will make. God’s knowledge is comprehensive and perfect, but it does not override or negate human free will.

Me : JEHOVAH is the first and most consequential cause of all events in the creation he is no mere passive observer of the future he creates the future actively or passively,any event JEHOVAH Foreknows he has the power to actively or passively alter,so he can foreknow several outcomes to the same chain of events, the example of the sun's rising in the east was made JEHOVAH Can easily arrange to have the sun rise in the west or any other direction or not at all habakkuk ch.3:11,

To argue then that JEHOVAH Does not have the might and wisdom to make certain aspects of the future undetermined or to alter his own previous determinations of said future is to misunderstand the scriptures true position re:JEHOVAH'S Sovereignty over his creation.

Amos ch.7:1-6NIV"This is what the Sovereign LORD showed me: He was preparing swarms of locusts after the king’s share had been harvested and just as the late crops were coming up. 2When they had stripped the land clean, I cried out, “Sovereign LORD, forgive! How can Jacob survive? He is so small!”

3So the LORD relented.

“This will not happen,” the LORD said.

4This is what the Sovereign LORD showed me: The Sovereign LORD s calling for judgment by fire; it dried up the great deep and devoured the land. 5Then I cried out, “Sovereign LORD, I beg you, stop! How can Jacob survive? He is so small!”

6So the LORD relented.

“This will not happen either,” the Sovereign LORD said..

4This is what the Sovereign LORD showed me: The Sovereign LORD was calling for judgment by fire; it dried up the great deep and devoured the land. 5Then I cried out, “Sovereign LORD, I beg you, stop! How can Jacob survive? He is so small!”

6So the LORD relented.

“This will not happen either,” the Sovereign LORD said."

JEHOVAH as the source of all the energy and information in the creation causes the future not an exhaustively predetermined future but he uses his Sovereign power to safeguard our freewill


Nincs:You mention that because the future is not fully foredetermined, it cannot be precisely foreknown. However, this claim assumes that for something to be known, it must be determined. This is not the case, especially when considering the nature of God. God's knowledge is not contingent on causality in the way human knowledge is. God’s knowledge is complete and eternal, meaning that He knows the outcomes of all free decisions without needing to cause them. This understanding preserves both the sovereignty of God and the genuine freedom of human beings.

Me:It's basic logic every contingent event/occurrence has a chain of causes that precedes it JEHOVAH Being the first cause and the source of all the information an energy in the creation. So if an outcome is inevitable the chain of causes leading up to it logically has already begun . If it was inevitable from prior to the creation then the creator himself must be included in that chain of causes he being the first cause, and bearing in mind he has the power to alter outcomes,

The only way to preserve human freedom is for morally consequential outcomes to not be inevitable from eternity,



Nincs:Regarding your assertion that Christendom posits an "apology for free will" that is "really no free will at all," this seems to be a misunderstanding of what Christian theologians, especially within Catholic and many Protestant traditions, actually teach. The doctrine of predestination, as understood in these traditions, does not imply absolute determinism. For example, the Catholic Church teaches that God predestines no one to damnation and that human beings are fully capable of making free choices that have real moral significance. The Council of Trent, for example, affirmed the reality of human free will while also upholding the necessity of divine grace.

A vain attempt to reconcile what is logically irreconcilable if an outcome is inevitable prior to my existence ,logically I have no choice, the chain of causes that rendered the outcome inevitable preceded my existence JEHOVAH would have chosen to not mitigate the chain of causes that made the outcome inevitable and thus would be culpable as the first cause in my failure.


Nincs:Your critique of "absolute predeterminism" as absurd is addressing a straw man rather than the actual beliefs of most Christian traditions. Absolute predeterminism, where all events are caused by God in a way that negates human freedom, is not a position held by mainstream Christianity. Instead, what is often taught is that God's foreknowledge includes a divine plan where human freedom plays a real and vital role. This is not absurdity but a sophisticated understanding of how divine omniscience and human freedom coexist.

Me: it is your lack of rationality that is the problem whatever outcomes that JEHOVAH foreknows are inevitable every outcome has a chain of causes preceding it if an outcome is inevitable the chain of causes leading up to it has already begun that is just the way causality and contingency works. JEHOVAH Has the power to mitigate secondary causes and alter outcomes if he chooses not to then he bears some responsibility for the outcome. So your claim that the totality of the future is foreknown is the same as saying every decision and outcome is inevitable,which is the same as saying that there is no freewill.

Nincs:Finally, your point about true moral excellence being impossible under the doctrine of predeterminism is based on a misunderstanding. In Christian thought, moral excellence is possible precisely because humans have the freedom to choose between good and evil, even within the scope of God’s omniscient knowledge. God's foreknowledge does not constrain human freedom; rather, it encompasses it, allowing for the genuine exercise of free will and moral responsibility.

Me: JEHOVAH'S Omniscience is not the issue He has the might and the right to create a universe that leaves morally consequential choices undetermined hence not inevitable if our decisions were inevitable from eternity there is no freewill and all of your circular arguments will not make it otherwise.


Nincs:In summary, the notion that God’s foreknowledge negates human free will is a misconception. Traditional Christian doctrine affirms that God’s omniscience and human freedom are compatible, and that God’s foreknowledge does not equate to predetermination. This balance between divine knowledge and human free will is what allows for true moral agency and the potential for moral excellence.

Me:it is simply logical that once an outcome is accurately foreknown it is inevitable from that point if this inevitability precedes the existence of the agent the agent cannot rightly be held responsible for the outcome. Basic logic. 

Sunday 28 July 2024

More on the search for a third way.

 

On striking the Cambrian jackpot.

 Fossil Friday: Cambrian Explosion Bingo Continues


This Fossil Friday features the weird critter Hallucigenia from the Cambrian Burgess Shale, as we discuss the most recent contribution to the Cambrian Explosion bingo game, which is how I prefer to call the popular exercise in wild speculation and unsubstantiated guesswork among evolutionary biologists to explain the abrupt appearance of animal body plans in the Cambrian Explosion about 535-515 million years ago. Among the many different causes that have been proposed as alleged drivers of the Cambrian Explosion, an increase in oxygen levels represents one of the most popular alternatives (e.g., see Zhang & Cui 2016, He et al. 2019). It was claimed that “oxygen linked with the boom and bust of early animal evolution” (University of Oxford 2019). Even as recently as two years ago, scientists found that there were “pulses of atmosphere oxygenation during the Cambrian radiation of animals” and “oxygen availability was a crucial factor in accelerating the radiation of marine animals” (Jiang et al. 2022).

This just in

Now, a new study by Stockey et el (2024), just published in the journal Nature Geoscience, did not “find evidence for the wholesale oxygenation of Earth’s oceans in the late Neoproterozoic era”, but instead just a “moderate long-term increase”. The authors suggest that this small increase “provides some of the most direct evidence for potential physiological drivers of the Cambrian radiation.” Consequently the press releases and media headlines cheered that scientists found that “a rapid burst of evolution 540 million years ago could have been caused by a small increase in oxygen” (Castañón 2024), and a “small change in Earth’s oxygen levels may have sparked huge evolutionary leap” (University of Southampton 2024), and “life only needed a small amount of oxygen to explode” (Watson 2024). This is quite surprising, as the latter author explicitly admitted that “it’s long been thought that a monumental surge in oxygen fuelled the Cambrian explosion” (Watson 2024). However, suddenly it allegedly was not a monumental surge but just a small long-term increase that made this miracle happen. Hey, no big deal, they just creatively changed the narrative.

Who Cares About Yesterday’s Petty News?

 bet that if scientists were to discover next month that there was no oxygenation in the Cambrian but the exact opposite, they would quickly reverse their just-so-story and claim that it was lower oxygen levels that caused the Cambrian Explosion. If you doubt that distinguished scientists could or would ever be that sloppy and cunning, just look what they did with the event that preceded the Cambrian Explosion in the Ediacaran. Spoiler alert: they did exactly that, which I already discussed at length in a previous article (Bechly 2023a) and podcast (Bechly 2023b). Check it out if you want to dig deeper down this rabbit hole.

References

Bechly G 2023a. Fossil Friday: Seventy Years of Textbook Wisdom on Origin of Multicellular Life Turns Out to Be Wrong. Evolution News September 1, 2023. https://evolutionnews.org/2023/09/fossil-friday-seventy-years-of-textbook-wisdom-on-the-origin-of-multicellular-life-turns-out-to-be-wrong/
Bechly G 2023b. Günter Bechly on Why Seventy Years of Textbook Wisdom Was Wrong. ID the Future episode 1813. https://idthefuture.com/1813/
Castañón L 2024. Revisiting the Cambrian explosion’s spark. Stanford Report July 2, 2024. https://news.stanford.edu/stories/2024/07/revisiting-the-cambrian-explosion-s-spark
He T, Zhu M, Mills BJW et al. 2019. Possible links between extreme oxygen perturbations and the Cambrian radiation of animals. Nature Geoscience 12, 468–474. DOI: https://doi.org/10.1038/s41561-019-0357-z
Jiang L, Zhao M, Shen A, Huang L, Chen D & Cai C 2022. Pulses of atmosphere oxygenation during the Cambrian radiation of animals. Earth and Planetary Science Letters 590: 117565. DOI: https://doi.org/10.1016/j.epsl.2022.117565
Stockey RG, Cole DB, Farrell UC et al. 2024, Sustained increases in atmospheric oxygen and marine productivity in the Neoproterozoic and Palaeozoic eras. Nature Geoscience. DOI: https://doi.org/10.1038/s41561-024-01479-1
University of Oxford 2019. Oxygen linked with the boom and bust of early animal evolution. University of Oxford News & Events May 13, 2019. https://www.ox.ac.uk/news/2019-05-13-oxygen-linked-boom-and-bust-early-animal-evolution
University of Southampton 2024. Small change in Earth’s oxygen levels may have sparked huge evolutionary leap. Phys.org July 2, 2024. https://phys.org/news/2024-07-small-earth-oxygen-huge-evolutionary.html
Watson C 2024. Life Only Needed A Small Amount of Oxygen to Explode, Scientists Find. ScienceAlert July 7, 2024. https://www.sciencealert.com/life-only-needed-a-small-amount-of-oxygen-to-explode-scientists-find
Zhang X & Cui L 2016. Oxygen Requirements for the Cambrian Explosion. Journal of Earth Science 27(2), 187–195. DOI: https://doi.org/10.1007/s12583-016-0690-8

Thursday 25 July 2024

Mutation is no friend of Darwinism?

 On Developmental Gene Regulatory Networks, the Scientific Literature Supports Stephen Meyer


In  a post yesterday we saw that Stephen Meyer wrote extensively about evo-devo in Darwin’s Doubt, effectively answering biologist Gerd Müller’s preferred evolutionary model for how new body plans arise. If I could boil down Meyer’s arguments to three points, they would be:

Evo-devo focuses on the role of special early-acting mutations in developmental processes to generate new body plans, but over 100 years of mutagenesis experiments show that mutations in genes regulating development are invariably deleterious (or in some cases have only trivial effects). Meyer summarizes: “This generates a dilemma: major changes are not viable; viable changes are not major. In neither case do the kinds of mutation that actually occur produce viable major changes of the kind necessary to build new body plans.”
We see these deleterious effects particularly in experiments on developmental gene regulatory networks (dGRNs), complex networks of gene-interaction which regulate the expression of genes early in development as an organism’s body plan begins to grow. After reviewing experimental work on dGRNs, Meyer finds that, “These dGRNs cannot vary without causing catastrophic effects to the organism.” 
These experimental results on dGRNS have profound implications for organismal evolution, because if changes to dGRNs are lethal to an embryo, how can they be modified to explain how new body plans evolve? Meyer’s writes in the book: “The system of gene regulation that controls animal-body-plan development is exquisitely integrated, so that significant alterations in these gene regulatory networks inevitably damage or destroy the developing animal. But given this, how could a new animal body plan, and the new dGRNs necessary to produce it, ever evolve gradually via mutation and selection from a preexisting body plan and set of dGRNs?” (Darwin’s Doubt, p. 269)
Gerd Müller is aware that Meyer has talked about dGRNs, because Meyer mentioned them (albeit briefly) on the Joe Rogan podcast last year, and Müller even made a comment in response, saying: “he [Meyer] mentions gene regulatory networks but stops short of making the obvious argument that mutations in these gene regulatory networks you don’t need so many random mutations to create an important change of the phenotype.” But if Meyer is correct then random mutations in dGRNs are lethal to the embryo

The Literature Supports Meyer’s Arguments

Meyer was justified in making these arguments. The work of the late Caltech developmental biologist Eric Davidson, an eminent expert in the field of evo-devo, shows that mutations in genes that affect body plan characteristics (which tend to be expressed early, as the body plan is being put in place) don’t lead to new body plans — they lead to dead embryos. Meyer wrote about Davidson in Darwin’s Doubt, as we saw yesterday. But it’s worth providing some more expansive background in Davidson’s own words:

[T]here is a high penalty to change [in dGRNs], in that interference with the dynamic expression of any one of the genes causes the collapse of expression of all, and the total loss from the system of their contributions to the regulatory state … there is always an observable consequence if a dGRN subcircuit is interrupted. Since these consequences are always catastrophically bad, flexibility is minimal, and since the subcircuits are all interconnected, the whole network partakes of the quality that there is only one way for things to work. And indeed the embryos of each species develop in only one way.

[…]

A few years ago remarkably conserved subcircuits, termed network “kernels” that operate high in the dGRN hierarchy were discovered. … the kernels similarly canalize downstream developmental process in each member of each given clade.

[…]

Evolutionary inflexibility due to highly conserved canalizing dGRN kernels

As discussed above these subcircuits operate at upper levels of dGRN hierarchy so as to affect characters of the body plan that are definitive for upper level taxa, i.e., they control the early stages of just the types of developmental process of which the invariance per taxon constitutes our problem. Since they preclude developmental alternatives, they may act to “booleanize” the evolutionary selective process: either body part specification works the way it is supposed to or the animal fails to generate the body part and does not exist.

ERIC DAVIDSON, “EVOLUTIONARY BIOSCIENCE AS REGULATORY SYSTEMS BIOLOGY,” DEVELOPMENTAL BIOLOGY, 357:35-40 (2011)

Or this

Interference with expression of any [genes in the dGRN kernel] by mutation or experimental manipulation has severe effects on the phase of development that they initiate. This accentuates the selective conservation of the whole subcircuit, on pain of developmental catastrophe.

DAVIDSON AND ERWIN. “AN INTEGRATED VIEW OF PRECAMBRIAN EUMETAZOAN EVOLUTION,” COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY, 74: 1-16 (2010)

This intolerance of body plan-affecting dGRNs to fundamental perturbations indicates that they could not have evolved by undirected mutations. Many coordinated mutations would be needed to convert one functional dGRN that generates a particular body plan into a different dGRN that generates a different body plan. 

The classic rejoinder

Meyer is also well aware of what evo-devo proponents say in response to these arguments and he has a ready rebuttal. The classic rejoinder from evo-devo proponents is to propose that perhaps in the past somehow dGRNs were more “labile” or “flexible” and easier to evolve. Indeed, Davidson acknowledges that something must have been different when body plans first evolved, which removed this resistance to change:

Deconstructing the evolutionary process by which stem group body plans were stepwise formulated will require us to traverse the conceptual pathway to dGRN elegance, beginning where no modern dGRN provides a model. The basic control features of the initial dGRNs of the Precambrian and early Cambrian must have differed in fundamental respects from those now being unraveled in our laboratories. The earliest ones were likely hierarchically shallow rather than deep, so that in the beginning adaptive selection could operate in a larger portion of their linkages. Furthermore, we can deduce that the outputs of their sub-circuits must have been polyfunctional rather than finely divided and functionally dedicated, as in modern crown group dGRNs….

ERIC DAVIDSON, “EVOLUTIONARY BIOSCIENCE AS REGULATORY SYSTEMS BIOLOGY,” DEVELOPMENTAL BIOLOGY, FEBRUARY 2011

Davidson says there that “no modern dGRN provides a model” for how new dGRNs might evolve. Therefore he believes that, when new body plans arose, dGRNs “must have differed in fundamental respects from those now being unraveled in our laboratories.” Davidson is not the only evolutionary scientist to use this form of argument. Paleontologist Charles Marshall said much the same in 2013 when responding in the journal Science to Meyer’s arguments in Darwin’s Doubt regarding dGRNs. Marshall argued that although Meyer is correct to observe that “manipulation of such networks is typically lethal,” this is not a problem for evolution because “GRNs at the time of the emergence of the phyla were not so encumbered.” Indeed, Müller’s intermediary, Forest Valkai, makes a similar (though less eloquently stated) argument in the video attacking Meyer. 

But how does Marshall or Valkai or anyone know that dGRNs were so different in the past? Similarly, how does Davidson know that early dGRNs “must have differed in fundamental respects” from those we observe? Do they know this from experiments and direct observation, or from evolutionary theory itself? The answer is evolution; more precisely, the common descent of the animals. If the animal phyla shared a common ancestor that was itself a developing species, dGRNs of the past must have been more “flexible” or “labile” — totally unlike what we observe today.

But would such a flexible or labile dGRN actually produce a viable animal? We don’t know, because we have no observational evidence. As such, to salvage evo-devo models of evolution from the contrary experimental data, Davidson and Marshall reverse the normal method of historical sciences. Present-day observations are no longer the key to the past. Rather, a theoretical model dictates what must have happened in the past — even if that model contradicts what we know from the evidence. Meyer put it this way in the Epilogue to Darwin’s Doubt

By ignoring this evidence, Marshall and other defenders of evolutionary theory reverse the epistemological priority of the historical scientific method as pioneered by Charles Lyell, Charles Darwin, and others. Rather than treating our present experimentally based knowledge as the key to evaluating the plausibility of theories about the past, Marshall uses an evolutionary assumption about what must have happened in the past (transmutation) to justify disregarding experimental observations of what does, and does not, occur in biological systems. The requirements of evolutionary doctrine thus trump our observations about how nature and living organisms actually behave. What we know best from observation takes a backseat to prior beliefs about how life must have arisen. 

What we do know from experience, however, is that large increases in functionally specified information — especially information expressed in an alphabetic or digital form — are always produced by conscious and rational agents. So the best explanation for the explosion of information necessary to produce the Cambrian animals (whether that explosion occurred during or before the Cambrian period) remains intelligent design.

DARWIN’S DOUBT, P. 448

What this means is that although evo-devo has some interesting ideas, evolutionary biology currently lacks a model that is validated by experimental evidence showing that dGRNs — and hence body plans — are mutable and capable of evolving from one form to another.  

More Evo-Devo Problems

But Meyer isn’t done recounting problems with evo-devo-based models of evolution. In Darwin’s Doubt he offers additional reasons why mutations in Hox genes can’t build new body structures:

Third, Hox genes only provide information for building proteins that function as switches that turn other genes on and off. The genes that they regulate contain information for building proteins that form the parts of other structures and organs. The Hox genes themselves, however, do not contain information for building these structural parts. In other words, mutations in Hox genes do not have all the genetic information necessary to generate new tissues, organs, or body plans. 

Nevertheless, Schwartz argues that biologists can explain complex structures such as the eye just by invoking Hox mutations alone. He asserts that “[t]here are homeobox genes for eye formation and that when one of them, the Rx gene in particular, is activated in the right place and at the right time, an individual has an eye.” He also thinks that mutations in Hox genes help arrange organs to form body plans.

In a review of Schwartz’s book, Eörs Szathmáry finds Schwartz’s reasoning deficient. He too notes that Hox genes don’t code for the proteins out of which body parts are made. It follows, he insists, that mutations in Hoxgenes cannot by themselves build new body parts or body plans. As he explains, “Schwartz ignores the fact that homeobox genes are selector genes. They can do nothing if the genes regulated by them are not there.” Though Schwartz says he has “marveled” at “the importance of homeobox genes in helping us to understand the basics of evolutionary change,” Szathmáry doubts that mutations in these genes have much creative power. After asking whether Schwartz succeeds in explaining the origin of new forms of life by appealing to mutations in Hox genes, Szathmáry concludes, “I’m afraid that, in general, he does not.”

Nor, of course, do Hox genes possess the epigenetic information necessary for body-plan formation. Indeed, even in the best of cases mutations in Hox genes still only alter genes. Mutations in Hox genes can only generate new genetic information in DNA. They do not, and cannot, generate epigenetic information.

Instead, epigenetic information and structures actually determine the function of many Hox genes, and not the reverse. This can be seen when the same Hox gene (as determined by nucleotide sequence homology) regulates the development of different anatomical features found in different phyla. For instance, in arthropods the Hox gene Distal-less is required for the normal development of jointed arthropod legs. But in vertebrates a homologous gene (e.g., the Dlx gene in mice) builds a different kind of (nonhomologous) leg. Another homologue of the Distal-less gene in echinoderms regulates the development of tube feet and spines — anatomical features classically thought not to be homologous to arthropod limbs, nor to limbs of tetrapods. In each case, the Distal-less homologues play different roles determined by the higher-level organismal context. And since mutations in Hox genes do not alter higher-level epigenetic contexts, they cannot explain the origin of the novel epigenetic information and structure that establishes the context and that is necessary to building a new animal body plan.

DARWIN’S DOUBT, PP. 320-321

What we see from the passage quoted above, as well as from Meyer’s extensive discussion of evo-devo in Darwin’s Doubt, is that Gerd Müller is far from correct in comparing Meyer to a “gene reductionist” who thinks that only mutations in genes are needed to evolve new types of organisms. In contrast, Meyer is well aware of non-neo-Darwinian models of organismal evolution like evo-devo, which focus on the role of mutations in changing regulatory networks of genes to generate radically new body plans. Meyer also explores how non-genetic or epigenetic information is necessary to generate new body plans, and how evolutionary models seem unable to produce this information as well. 

In sum, Meyer has offered extensive arguments about evo-devo generally, and in particular about dGRNs. He shows that dGRNs can’t change significantly without development shutting down, which means that there is a problem with finding mutations that can suddenly produce large-scale changes to radically alter the body plan of an organism. Since all evolution requires change, this problem applies across the board to all evolutionary claims about the origin of new body plans, not just neo-Darwinian models. The Joe Rogan podcast last year only afforded the opportunity to scratch the surface, but it’s clear that Meyer has a lot to say and that Müller really has not responded to him in any relevant detail

An Invitation to Dialogue

As a fifth and final point, we would love to hear what Professor Müller thinks of all of this. Clearly, Meyer has invested a lot of time and energy into addressing Müller’s field of evo-devo and has developed detailed, careful arguments about the viability of evo-devo-based models. I would welcome a response from Professor Müller. However, I think that our website, Evolution News, would be a better place for dialogue than Professor Müller’s responding indirectly through an angry YouTuber’s channel, with all the personal attacks and other distasteful antics that go with that particular venue. Müller deserves better.

We would be happy to host such a dialogue here at Evolution News, and I therefore invite Professor Müller to send us a robust response to Stephen Meyer’s arguments about evo-devo models of evolution. In that way, real progress can be made in this conversation