Wednesday, 17 July 2024
Tuesday, 16 July 2024
Neanderthals receive their rightful inheritance?
Neanderthals Were a Lot More Like Humans than We Realize
News stories at Phys.org and IFLS are reporting on a new paper in Science which finds more evidence of human-Neanderthal interbreeding. The Editor’s summary of the technical paper notes, “there is now ample evidence for gene flow from Neanderthals to humans and vice versa.” Under the standard biological definition of a “species,” such evidence of interbreeding would indicate that humans and Neanderthals should in fact be considered members of the same species.
But there’s a lot of baggage in the way of that view. Mainstream paleoanthropologists would not say that we are directly descended from Neanderthals, but they are often promoted as an evolutionary relic representing a primitive stage of human evolution. As a 2020 paper in History and Philosophy of the Life Sciences says: “To most researchers however, the Neanderthal represented an ancient, inferior race of Homo sapiens, an extension into the past of the hierarchy of living human ‘races’, descending from civilized to savages.” But this view is increasingly countered by mainstream scientists who are saying that Neanderthals were just as advanced as contemporary humans.
Most Unkind to Neanderthals
A few months back, Smithsonian Magazine published an article about Neanderthals noting that “we haven’t been very kind to Neanderthals since their remains were first unearthed in the 19th century, often characterizing them as lumbering dimwits or worse.” Yet there is evidence that they used creativity and symbolism
Hundreds of intentionally broken stalagmites were found there, arranged into two large, ellipsoid structures and several smaller stacks, during a time when — as researchers confirmed in 2016 — only Neanderthals were roaming Europe. No one knows what these structures were for, but they suggest a tendency toward creativity and perhaps even symbolism
“Rethinking Neanderthals”
A 2023 article titled “Rethinking Neandertals” in Annual Review of Anthropology, previously reviewed by Günter Bechly, notes that Neanderthals used symbolism much like modern humans
The use of symbols is often argued to be a defining feature of H. sapiens. Growing evidence, however, supports the use of symbols by Neandertals in the form of personal ornaments, portable art, and spoken language (see the section titled Language, Cognition, and Brain Development) and possibly cave painting, although the latter remains somewhat controversial.
According to the paper, there are multiple potential examples of Neanderthals creating cave art:
The paper reports, “New research suggests that Neandertals were responsible for some hand-stencils, painted lines, and dots in multiple caves in Spain.” The cave art is controversial because some argue the dates are too young to be the work of Neanderthals.
At the French cave site La Roche-Cotard, there are 57,000-year-old “digital tracings” or “finger flutings” associated with Neanderthals. However, “The meaning of these tracings currently remains ambiguous … they are not necessarily symbolic in nature.”
At the Einhornhöhle site in Germany there is an engraved phalanx bone of a giant deer that dates to 51,000 years.
A “hashtag” like symbol from Gorham’s cave in Gibraltar, Spain.
A “pecked pebble from the Axlor Rockshelter in Spain.”
It is also argued that there are Neanderthal adornments, including a necklace made of eagle talons found in Croatia, “personal ornaments in the form of perforated, painted, and unpainted large marine bivalves,” and other possible examples of adornments. The Smithsonian Magazine article notes that Neanderthals may have used rope, red ochre pigments, and feathers in adornments.
Peeters and Zwart (2020) summarize this evidence:
[A] mounting body of evidence continues to expand the known repertoire of sophisticated strategies and symbolism practiced by Neanderthals, and sapiens-centrism has come under pressure. The more data we gather on their behaviour, the more similar Neanderthals seem to be to the modern human pattern. Not only dental hygiene, also large-scale cooperative hunting, complex stone tools, language, planning, care for the ill, imagination and symbolic behaviour, was present in Neanderthals. The only traceable advantage of Homo sapiens was that they had started to produce ornaments with little beads and shells, something which seemed absent in Neanderthal culture. Recent research, however, yielded perforated and ochre marine shells and colorants attributed to Neanderthals, suggesting once again that they were cognitively indistinguishable from modern humans. [Internal citations removed.]
Intelligence and Culture
Going back to the Smithsonian article, it quotes researchers remarking on just how much our understanding of Neanderthal intelligence and culture has changed in recent years:
In addition, the many freshly unearthed or newly analyzed artifacts, some now confidently assigned to Neanderthals thanks to improved methods for dating archaeological finds, make for quite a collection. “If you’d have asked me 20 years ago, I would have said there was quite a big gap in behavior, and Neanderthals would have lacked many of the complex behaviors we find in Homo sapiens,” Stringer says. “Now that gap has narrowed considerably.”
Of course there’s still much we don’t know and the evidence is sparse — due in part to the fact that Neanderthals probably had a relatively small overall population size. But as time goes on, the “gap” between humans and Neanderthals seems to be narrowing, not expanding — and this trend line has profound implications for whether Neanderthals really were the primitive brutes they’re often portrayed as.
Monday, 15 July 2024
Sunday, 14 July 2024
Friday, 12 July 2024
Blind cavefish Darwinian evolution or adaptive devolution?
Blind Cavefish: Evolutionary Icon, or an Example of Preprogrammed Adaptation?
The blind cavefish, Astyanax mexicanus, is often cited as a textbook example of Darwinian evolution. The dramatic transformation from a pigmented surface fish with eyes to a nonpigmented cave-dwelling fish with no eyes is presented as strong evidence for unguided evolution. But scientists with a different perspective have started studying this fish to see if the predictions of Darwinian theory actually hold true. Let’s look at some recent research.
Standard Darwinian theory makes the following claims:
Random mutations changed the fishes’ pigmentation.
Random mutations deactivated the fishes’ eyes.
These changes happened over a long period of time.
Fish without eyes and pigment had a reproductive advantage in the cave environment.
Continuous Environmental Tracking
However, there is another model that could explain the transformations of the cavefish. This model is called continuous environmental tracking (CET) and it is design-based. The model presupposes that organisms actively track conditions within specific environments and self-adjust based on predesigned adaptation trajectories. Similar to human engineered agile systems, organisms can make internal changes within a range in response to external changes. This model posits:
Genetic changes are directed and repeatable, not random.
Adaptation may be based on epigenetic or gene expression changes.
Adaptation is rapid since it is programmed and not dependent upon the accumulation of random changes.
A sensory mechanism exists to determine when the fish should undergo these changes.
According to CET, adaptive outcomes are expected to be highly regulated, rapid, repeatable, and, in some cases, reversible. Adaptations are anticipated to encompass a spectrum ranging from physiological changes that happen to an individual within a single lifetime to generational changes, which happen more slowly across multiple generations. This model views environmental changes as triggers for organismal sensing rather than as a selective agent.
Similar Adaptations for Different Cave-Dwelling Animals
Organisms that live in caves are called troglobites (different from the more familiar troglodyte, a human who lives in a cave). They commonly exhibit similar traits to the blind cavefish, including: loss of pigmentation, reduced or absent eyes, enhanced non-visual senses, slower metabolism, specialized reproductive strategies, and extended longevity. This suggests these traits are a non-random, purposefully designed response to the cave environment.
Recent Research on Cavefish
First, cavefish populations are now known “to exhibit repeated, independent evolution for a variety of traits including eye degeneration, pigment loss, increased size and number of taste buds and mechanosensory organs, and shifts in many behavioral traits.” (McGaugh et al. 2014) Are these repeatable, parallel changes an incredible display of natural selection acting on random mutation in the same ways over and over again — i.e., “convergent evolution”? Or is something else going on? Observations of repeatable changes in traits in independent populations are more consistent with a model of preprogrammed adaptability, whereby a designer frontloads genetic variability for different environments at the population level.
One hypothesis is that there exists distributed information within the population whereby different individuals represent different optimizations for unique environments. A while back, I covered morphological changes in guppies, where more research has been done than with the cavefish. For the guppy, distributed information (i.e., variation — though not necessarily generated by random mutation) at the population level seems to be the favored current hypothesis. Guppy traits change based on baked in genetic variation, which allows changes along certain predesigned trajectories in different environments. Importantly, because the novelty generation is not “happening before our eyes,” I don’t find this evidence convincing for neo-Darwinian theory, which requires that variation arise due to random processes.
Second, developing vision turns out to be a very metabolically expensive process, accounting for as much as 15 percent of the resting metabolic rate early in development. Thus, loss of the visual system reduces the amount of energy necessary for development, which is important in the nutrient restricted cave environment. (Moran, Softley, and Warrant 2015) This means there is a purposeful reason why cavefish lose their eyes. Loss of eyesight appears to be a necessary trade-off given the extreme nutrient deprivation of the cave environment.
Third, an individual non-pigmented, eyeless cavefish was shown to nearly revert to a pigmented state after exposure to surface-like conditions (daily cycles of high-intensity, full-spectrum light for five months). (Boyle et al. 2023) This suggests color changes are probably not genetic, but more likely epigenetic and can happen to an adult fish over a period of five months.
Future Research Directions
The next step for researchers is to investigate the molecular mechanisms underlying these changes. Some of this work is already underway. Researchers used an approach called QTL mapping, where homozygous individuals for the trait of interest are crossed to produce an F1 generation. The F1 generation is then interbred or backcrossed to create the F2 or further generations. These generations have a combination of genetic material from the parents. The phenotypic information from these generations is logged and correlated with the genotypic information. This allows researchers to observe which regions of the genome segregate with the traits in question. When this was done for the guppy eye loss trait, QTL mapping implicated 2,408 genes out of a total of 23,042 genes. (McGaugh et al. 2014) Using some other techniques, the researchers lowered their gene list to 30 genes involved in these changes. But, even at 30 genes, it’s hard to imagine how random accumulation of 30 different mutations enabled this phenotypic change in multiple independent populations. Indeed, when many coordinated allele changes are observed as necessary for the development of a phenotype, this data is more consistent with movement of an organism along a predesigned trajectory of adaptation where, given the situation, the fish trades off certain things, like eyes, to function better in its new environment.
Conclusion
Recent research on the blind cavefish has shown that their transformations are reproducible, challenging the idea of random mutation accumulation. Other research has also revealed a significant functional reason for eye loss in cavefish. Additionally, studies have demonstrated that these transformations can occur much faster than previously believed. For example, a single cavefish was observed to reverse pigmentation within five months when exposed to daylight cycles. Recent QTL mapping has identified at least 30 genes involved in eye loss, which means transformations involve multiple genes, suggesting coordination.
While much work remains to be done, the current research trajectory aligns more with a design-based CET model. A deeper understanding of these processes will provide insights into whether the adaptations observed in the blind cavefish result from Darwinian evolution or preprogrammed adaptive responses. The current evidence, though, is highly suggestive.
References
Boyle, Michael J., Brian Thomas, Jeffery P. Tomkins, and Randy J. Guliuzza. 2023. “Testing the Cavefish Model: An Organism-Focused Theory of Biological Design.” Proceedings of the International Conference on Creationism 9 (1): 17.
McGaugh, Suzanne E., Joshua B. Gross, Bronwen Aken, Maryline Blin, Richard Borowsky, Domitille Chalopin, Hélène Hinaux, et al. 2014. “The Cavefish Genome Reveals Candidate Genes for Eye Loss.” Nature Communications 5 (October): 5307.
Moran, Damian, Rowan Softley, and Eric J. Warrant. 2015. “The Energetic Cost of Vision and the Evolution of Eyeless Mexican Cavefish.” Science Advances 1 (8): e1500363.
Thursday, 11 July 2024
Our sun sheds light on the thumb print of JEHOVAH.
The Wonder of Sunlight: Appreciating the Remarkable Coincidences that Make Life Possible
In recent articles (here, here and here), I have surveyed examples of properties of the periodic table of elements that appear to be designed to promote the existence of life. There is, however, a myriad of other features of our universe that appear to be delicately tuned for the existence of life — in particular, advanced life. Here, I will offer a summary of another class of such evidence — this one relating to the radiation emitted by the sun.
The Visual Band
The oxygen that we breathe is generated by the process of photosynthesis in the chloroplasts of green plants, a process that is energized by the light from the sun. Remarkably, the radiation emitted by the sun exhibits several remarkable coincidences that make life possible. Many forms of radiation make up the electromagnetic spectrum, each possessing a different wavelength. Within the inconceivably vast range of the electromagnetic spectrum, there exists a small band of radiation that possesses the right energy levels for photochemistry — allowing animals to see and green plants to photosynthesize. This corresponds to the visual band, together with the near ultraviolet and near infrared wavelengths that are closely adjacent to it. This band represents such an incredibly small fraction of the electromagnetic spectrum that it is difficult to do it justice. Concerning the inconceivable vastness of the electromagnetic spectrum, Michael Denton notes, “Some extremely low-frequency radio waves may be a hundred thousand kilometers from crest to crest, while some higher-energy gamma waves may be as little as 10-17 meters across (only a fraction of the diameter of an atomic nucleus). Even within this selected segment of the entire spectrum, the wavelengths vary by an unimaginably large factor of 1025 or 10,000,000,000,000,000,000,000,000.”1 The visual region of the spectrum represents a miniscule fraction of this, lying between wavelengths of 380 and 750 nm in length. Put another way, “the ‘right light’ would be only a few seconds in a time-span one hundred million times longer than the age of the Earth, or a few playing cards in a stack stretching beyond the galaxy of Andromeda — a fraction so small as to be beyond ordinary human comprehension.”2 It is a remarkable coincidence, then, that nearly half of the radiation emitted by the sun lies within this visual region.
The Infrared Region
As to the other half of the sun’s radiant output, this lies primarily in another infinitesimally small region of the spectrum that is adjacent to the visual region, between the wavelengths of 750 to somewhat beyond 2,500 nm. This infrared radiation provides approximately half of the essential heat that is needed to warm the atmosphere of our planet. Denton remarks, “Without it Earth’s entire surface would be a frozen wilderness far colder than the Antarctic. It is thanks to the heat of the sun (and to our atmospheric gases absorbing this heat) that water exists in liquid form on Earth’s surface and the average global atmospheric temperature is maintained well above freezing, in a temperature range which enables the chemistry of life to proceed.”3
Denton concludes, that “this is a genuine coincidence, as the compaction of solar radiation into the visible and near infrared is determined by a completely different set of physical laws from those that dictate which wavelengths are suitable for life and photosynthesis.”4 One might be tempted to ask here whether, given the sheer number of stars in our universe (conservatively estimated at 1024), our sun might be the lucky winner of a cosmic lottery. But, in fact, most stars emit the majority of their radiation in the visible and infrared region.
Penetration of Visual Light
Of course, photosynthesis also requires that the visual light be allowed to penetrate the atmosphere and reach the ground, and that part of the sun’s infrared radiation be absorbed in order to warm our planet to the degree that photosynthesis can take place. It is an exquisitely fortuitous coincidence, then, that Earth’s atmosphere not only allows penetration of almost all of the radiation in the visual region, but also absorbs a significant proportion of the infrared radiation, thereby warming the Earth into the ambient range. In addition, our atmosphere absorbs the dangerous radiation on either side of the visual and near-infrared regions of the spectrum.
Finally, in order for photosynthesis to take place, the visual light must be able to penetrate water, since the light must traverse the water in the cell of any green plant in order to reach the chloroplasts. And, indeed, water — whether in its liquid, gaseous or solid form — is transparent to visual light. If the water vapor in the atmosphere or the liquid water of the cell absorbed the visual band, there could be no photosynthesis, and no aerobic form of life would exist.
Remarkable Coincidences
Photosynthesis is absolutely essential to the existence of advanced life forms. And yet it is easy to imagine a plethora of scenarios where, if our universe were just slightly different, photosynthesis could not take place, and no aerobic forms of life could exist. Since advanced life is not particularly surprising given theism but extremely surprising given naturalism, this evidence tends to confirm the existence of a creator. For a much more detailed discussion of the properties of sunlight that make advanced life possible, I recommend Michael Denton’s book, Children of Light: The Astonishing Properties of Sunlight That Make Us Possible.
Notes
Michael Denton, Children of Light: The Astonishing Properties of Sunlight That Make Us Possible (Discovery Institute Press, 2018), chapter 2.
Ibid.
Michael Denton, The Miracle of Man: The Fine Tuning of Nature for Human Existence (Discovery Institute Press, 2022), 52.
Ibid.
Wednesday, 10 July 2024
Ever more are daring to deny Darwin?
Oxford Physiologist Denis Noble: Dissent from Neo-Darwinism Has Passed a “Tipping Point”
Forbes recently ran an article with an attention-grabbing headline: “Evolution May Be Purposeful, and It’s Freaking Scientists Out.” Readers of Evolution News immediately began emailing us about it. On anything relating to evolution versus intelligent design, it used to be that Forbes could be counted on for snarky put-downs of ID, perhaps more so than many another mainstream publication. The times, it seems, are changing. The article by science writer Andréa Morris was based largely on a video interview with retired Oxford physiologist Denis Noble, and it highlights the evidence for “teleonomy” (internal purposiveness) that some scientists have been trying to call attention to:
It’s about time. We were wondering when the (often very dramatic) claims made recently in arcane academic texts — such as the essays collected in MIT Press’s 2023 anthology Evolution “On Purpose” — would begin making more of a splash in the popular media. Those essays, and Noble’s own perspective, are not in favor of intelligent design. But you might say they are, if this is not going too far, “ID adjacent.” Many themes will be familiar to those who follow the literature of intelligent design.
But aside from that positive development, there is another point in the article and the accompanying interview that is worth drawing out in detail here: the “very strange psychology,” as Dr. Noble calls it, that has been causing neo-Darwinists to dig their heals in and lash out at anyone who dares question the neo-Darwinian paradigm.
Noble testifies that some evolutionary biologists have been actively persecuting their fellow scientists who have attempted to deviate from the received consensus. (Gosh, who would have thought?) But according to Noble, the dam has broken and the dissent can no longer be contained.
Persecution? What Persecution?
Darwin apologists have habitually mocked and denied “claims of persecution” from ID proponents. So pay attention to Noble’s account in the Morris interview of how the situation was back in 2004:
Morris: So is it true…you mentioned this briefly, that it’s very hard in academia to talk about these ideas, these unorthodox ideas. And you didn’t feel you could actively start being head of this movement until you retired in 2004?
Noble: 2004 is when I retired from being a professor running a big laboratory. I was, therefore, from there on no longer responsible for applying to research organizations for grants to support the salaries of people in my group. So I was no longer in a position in which my own unorthodox views could damage the careers of people working in my laboratory. That’s the reason I only started writing in 2004. And the first publication was The Music of Life, which indeed is very clear about dissenting from the standard Neo-Darwinian synthesis. So all the way from 2006 I’ve been very clear about that. If I had been — as indeed I was for the first ten years or so when I first “came out,” if that’s the right way of putting it, on this this issue — I was denigrated. And with some pretty strong language. If that had damaged my reputation to the point of which it would have been difficult for to get the grant money that would support the salaries of a team, I would, in effect, by my own actions in relation to expressing my views on evolution, have damaged their careers. As simple as that. I couldn’t do that.
If that sounds bad, think about the fact that Noble wasn’t even denying the reality of Darwinian evolution, or crossing the red line of methodological naturalism. The view was just a critique of current evolutionary theory, from one Darwin-loving naturalist to another. Yet even that was too much to handle.
Morris then brings up the “vulgar attacks” Noble received from neo-Darwinists after he came out as a skeptic. The background of the video during her question displays a blog post by the inimitable Jerry Coyne titled “Famous physiologist embarrasses himself by claiming that the modern theory of evolution is in tatters.” Noble shares how the 2016 conference at the Royal Society in London reassessing evolutionary theory was almost shut down by neo-Darwinian fundamentalists:
Noble: In 2016, together with two other scientists and two philosophers, I organized a meeting at the Royal Society in London, the top academy of the United Kingdom, together with also the British Academy, which is the social science side of all of this, and we organized a meeting on “New Trends in Evolutionary Biology.” That meeting triggered a major protest from leaders of the neo-Darwinist synthesis. There was actually a protest to try and stop the meeting happening, in the form of a signed letter to the president of the Royal Society, saying, “Please, disassociate the Society from this meeting.” So, that meeting went ahead. There’s a history to that which we don’t need to go into, but it was quite a difficult history… I would love to find a way of defusing the tension and the standing off, that we experienced, for example, at that Royal Society meeting in 2016. There were just a few neo-Darwinists at the meeting, and it was like a gladiatorial confrontation. And I don’t think that’s necessary.
There’s Persecution, and There’s Persecution…
Again, Noble is not an ID proponent, or anything totally beyond the pale like that — or even a theist. Morris calls him “neutral on religious matters.” He is in fact a methodological naturalist. And he is a very distinguished scientist — one might even say venerable. He enjoyed a fruitful career at Oxford (where he was Richard Dawkins’s doctoral examiner back in the 1960s). Yet even he was not safe from mudslinging, vitriol, and outright suppression.
If this has been the situation for highly respected naturalists who merely want to critique contemporary evolutionary theory, without dissenting from Darwinism in general, much less the materialist worldview that underpins the whole endeavor — imagine how difficult it must be for those who go farther, or who are less secure in their careers?
Molecular biologist and intelligent design proponent Douglas Axe was also at the 2016 conference. This is what he wrote afterwards about the experience:
As important as parenting is, it should be a temporary undertaking. The end result is well worth the effort… when it does come to an end, that is. We’ve all seen regrettable cases where it doesn’t — fully grown adults who retain an unhealthy need for parental approval and aging parents who foster that kind of lingering dependence.
I left the recent Royal Society meeting in London, “New Trends in Evolutionary Biology,” with the distinct impression that I had witnessed a professional version of that unhealthy situation. Old-style neo-Darwinists were there, few in number but with a way of making their presence felt — like overbearing parents presiding over the affairs of their long-grown offspring. Emotional complaints were made against these parent figures during question periods, with spontaneous applause signaling a general mood of protest…
At the meeting I found myself siding with the protestors, but soon afterward I began to wonder whether maybe the “parents” were only partly to blame for the tension. I recalled one participant who, during question time, clearly identified the peculiarity of the protest stance. Addressing one of the speakers who exemplified that stance, he pointed out that this professor and her peers enjoyed good academic positions, complete with all the key ingredients for academic success: tenure, funding, publication records, positions on editorial boards, etc. Why complain, then?…
In fact, scientists who challenge not just the calcified version of evolutionary theory but the larger stream of naturalistic thought that gave birth to it have far more legitimate complaints than any aired at the London meeting. You can’t wade against this larger stream without jeopardizing those key ingredients of academic success. The academy, which has in recent decades become a self-righteous monoculture, vigorously opposes anyone who moves against it.
Maybe this regrettable situation will change, someday
Past the Tipping Point
Axe’s “maybe” was maybe less than optimistic, and his “someday” seemed implicitly to lie in the far-distant future. But since 2016 there have already been hints of a sea-change. Intelligent design hypotheses may still be anathema in most circles, but critiques of the received evolutionary paradigm are no longer slapped down. According to Noble:
The interesting thing is this: since that meeting, I am no longer attacked. The silence from the other side is deafening. Has there been any response to the Nature review that I did a few weeks ago with the very provocative title “Genes Are Not the Blueprint for Life”? Nobody’s replied. I look forward to a reply. But there’s been no reply either to the articles that were published in 2017 after that 2016 meeting at the Royal Society. I think there was a tipping point there.
As a result of taboo-breakers like Denis Noble in the early 2000s, today in 2024 there are young scientists who weren’t educated into the strict neo-Darwinian paradigm and feel free to diverge from it. One such scientist is a rising star of origin of life research, Joana Xavier, whom Morris interviewed for the Forbes article along with Noble. Xavier expresses no patience with the neo-Darwinist paradigm, and even less for the gatekeepers who insult and harm the careers of anyone who tries to bring new ideas to the table. She advocates going on the offensive: “We need to shame them,” she says. “I’m sorry, but we do.”
Xavier is an interesting case, and a measure of how some walls seem to be coming down. See here for her comments to Perry Marshall on Stephen Meyer’s Signature in the Cell. The ID tome is “one of the best books I’ve read in terms of really putting the finger on the questions,” and “I actually tell everyone I can, ‘Listen, read that book. Let’s not put intelligent design on a spike and burn it. Let’s understand what they’re saying and engage.’”
In fact, as a science journalist, Andréa Morris is not without interest herself. In her mentions of ID, she is nuanced, noting that the “reductionist, gene-centric model… forfeits natural phenomena like purpose due to its association with intelligent design and a transcendent, intelligent designer.” In the conversation with Noble, she’s candid: “I don’t believe in a God — I don’t believe in much of anything. But life, and that process, is magical” (at 57:28) Yet a sentence in her article says, “Noble believes that purpose, creativity, and innovation are fundamental to evolution.” Huh. “Purpose, creativity, and innovation” are, word for word, a phrase from Discovery Institute’s one-sentence mission statement.
What, is that some sort of secret handshake? Has she been reading our stuff? Actually, it seems she has. When Noble is talking about the 2016 Royal Society meeting, she illustrates with an image of an article here at Evolution News (at 1:07:30).
Be that as it may, as Xavier says there is no reason to tolerate the self-appointed censors any longer. The tipping point has already been passed, and the old consensus is in retreat. The more scientists take a chance and step outside the neo-Darwinian structure, the more obvious it will be that the structure was a prison, not a foundation.
And then — maybe — other structures will begin to be questioned as well.
Noble says:
What do I find now? I meet young people doing research in my university and in other universities who are working within a paradigm that is totally different from the neo-Darwinist paradigm. Can they do so?
Yes, they can.
Tuesday, 9 July 2024
Still seeking straight answers from trinitarians.
John ch.17:5NKJV"And now, O Father, glorify Me together [b]with Yourself, with the glory which I had with You before the world was."
Did the God and Father of Jesus Christ grant his Son's request?
Yet more on percieving the thumb print of JEHOVAH
Earth Left “A Path of Tools” to Scientific Discovery
Earth Left “A Path of Tools” to Scientific Discovery
The first few chapters of the wonderful new Discovery Institute Press book, The Farm at the Center of the Universe, by Guillermo Gonzalez and Jonathan Witt, present evidence for intelligent design in biology in the form of a novel, accessible to teens and young adults. Young Isaac, his older cousin Charlie, and their Grandpa discuss molecular machines, irreducible complexity, the fossil record, devolution vs. evolution, cells as remarkable factories that build factories (that build factories …), and the claim that intelligent design is not science. The authors manage to introduce these and other topics into the conversations in a surprisingly natural and accessible way, without sacrificing scientific accuracy, as I noted in my earlier review.
But Gonzalez is an astronomer and perhaps best known for the book The Privileged Planet, written with Jay Richards, and a video by the same name, so the last few chapters find Grandpa and Isaac looking though a telescope more often than a microscope.
We viewed several segments from the Privileged Planet video during my five-week class on intelligent design last summer. This ten-minute clip was shown to document some of the evidence for the local fine-tuning of conditions on Earth, and this short segment was used to help document evidence for the global fine-tuning of the laws and constants of physics and of the initial conditions of our
The Anthropic Principle
As discussed in this class, the standard “anthropic principle” objection to the use of these fine-tunings as evidence for design is to assert that there are many planets and many universes with different conditions, and naturally we would inhabit one of the few lucky planets and one of the few lucky universes which are life-permitting, because otherwise we wouldn’t be here to wonder why we are here. This objection is of course more reasonable when applied to the local fine-tuning, not only because there really are many other planets, and no evidence that there are other universes, but also because the range of parameters which could support any conceivable form of life is much narrower in the global case.
Designed for Scientific Discovery
But The Privileged Planet is best known for presenting evidence that not only are the conditions on our planet, and its location, ideal for survival but also for scientific discovery, as discussed in this 15-minute segment. So, I was delighted to see this topic discussed at length in the new book. Grandpa summarizes:
What amazes me is that we can see so much of our universe from right here on Earth. Our planet is astonishing. It is incredibly well set up to allow us to live here. And it is incredibly well set up to allow us to discover all manner of things, from tiny cells to the enormous universe.
In our summer 2023 class we also viewed these clips from Michael Denton’s video Fire Maker which present further evidence that the conditions on Earth are finely tuned for scientific discovery and technological progress, and so are the laws of physics of our universe
Set Up for Science
The fine-tunings for scientific discovery and technological progress are very interesting to me and not just because they defeat the anthropic principle, which only attempts to explain fine-tunings for survival. (We would still be here to wonder without these fine-tunings.) They are so satisfying to me because they show those scientists who insist that nothing could possibly be beyond the reach of their science that they have been able to reach so far with that science in the first place because they have been set up to do so!
At the end of Chapter 8 Isaac concludes “It’s almost like Earth wanted us to do science and invent things. Like someone left a path of tools for us to discover and use.” Gonzalez and Denton have provided us with evidence that supports this remarkable conclusion. One hopes future research will provide even more evidence.
Many thanks to Gonzalez and Witt for the new book, which is thought-provoking not only for its young target audience, but for all of us.
Monday, 8 July 2024
On the irreducible complexity of asexual reproduction.
Herding Chromosomes in the Mitosis Corral
My head is swimming after reading several recent papers on cell division. The multiplicity of molecules involved, and how they get where they need to be and do what they need to do — it is all so astonishing, it beggars description. I wish there were better ways to communicate to laypersons the emotional impact of learning about cell biology without drowning them in jargon like this excerpt from one paper about centrosomes:
During interphase, Cep57 forms a complex with Cep63 and Cep152, serving as regulators for centrosome maturation. However, the molecular interplay of Cep57 with these essential scaffolding proteins remains unclear. Here, we demonstrate that Cep57 undergoes liquid–liquid phase separation (LLPS) driven by three critical domains (NTD, CTD, and polybasic LMN). In vitro Cep57 condensates catalyze microtubule nucleation via the LMN motif-mediated tubulin concentration. In cells, the LMN motif is required for centrosomal microtubule aster formation. Moreover, Cep63 restricts Cep57 assembly, expansion, and microtubule polymerization activity….
Specialists are comfortable with this kind of talk, but we have a world of students being told that cells “emerged” by chance, and “evolved” into humans by blind, purposeless processes over millions of years. The facts above scream “No way!” but how do we tell non-scientists that without burying them in unfamiliar terms? Analogies and pictures can only go so far. I try my best, but simple explanations cannot do justice to the reality.
For students whose knowledge of mitosis may be limited to light-microscope images of dividing cells, or high-school biology diagrams of the five stages of cell division (interphase, prophase, metaphase, anaphase, telophase —“Ho-hum, will that be on the test?”), let me try to unpack some of the awesome wonders hidden in the above paragraph. It comes from a paper in PNAS by 15 specialists at the Institute of Bioinformatics and Structural Biology in Taiwan’s National Tsing Hua University. Respond with applause at each line:
Some molecules join forces to control other molecules!
Molecules assemble in compartments without a membrane to work in harmony!
Important things won’t happen unless all the parts are together! — and bad things happen if they fail!
Biochemistry is not your normal chemistry, where molecules collide like bumper cars and sometimes join up or break up. This is robotic factory work at a high level. With apologies to Jonathan Maclatchie, who knows the jargon and wrote at a more scholarly level recently (here), and to all the other practicing scientists who talk like this as their daily routine, we have to get the hay down where the cows can eat it. Students become so indoctrinated into materialistic scientism by the time they reach grad school (if they seek a career at that level), it becomes difficult for them to buck the evolutionary consensus once they start learning the real guts of cell biology. One almost must achieve tenure before being able to see without evolutionary blinders on. It happened one day to Michael Behe when he stared at an electron micrograph of a bacterial flagellum, and pondered: “That’s an outboard motor. That’s not a chance assemblage of parts.” His thought started a Revolution.
With hopes of generating some of the awe I felt in my reading, here goes my translation of what this paper revealed. The PhDs can skip the lay talk by clicking the link to the research.
The Mitosis Ranch
Trying to visualize this, I thought of the following analogy. Say a rancher must duplicate the cows in a corral and create two corrals with identical numbers and types of cows. He first has his cowboys yoke identical cows together (yokes representing the centromeres). They line the cows up between the two corrals, head to tail. Then other cowboys rope the cows from opposite directions, lassoing specialized “horns” on the yokes — the kinetochores. It takes a few tries for a cowboy to lasso the horn on his side of the yoke, but each one keeps trying till succeeding. An inspector checks that each yoked pair has one and only one rope on each side, and that the ropes are taut. When he gives a signal (the checkpoint), another cowboy goes down the line and breaks the yokes. The cowboys then pull their cows into the opposite corrals, and a gate closes between them.
The reality in cell division is much, much more intricate, but something like that really happens every time a eukaryotic cell divides. Hundreds of “cowboys” know their roles and know when to go into action. In the cell, though, the “cowboys” are blind and work in the dark. Are we beginning to be astonished yet? There’s much more!
Temporary Meeting Spaces
The PNAS paper reveals new knowledge about how the right molecules come together in the centrosome, a structure critical for pulling chromosomes apart during cell division. In mitosis, there are two centrosomes, one on each side of the cell. Centrosomes are where the mitotic spindle sends out the “ropes” to pull the chromosomes apart into the daughter corrals. Within each centrosome, two marvelously-symmetric centrioles grow perpendicular to each other (see here). They will be the organizing centers for the spindle microtubules. Microtubules will grow out from the centrosome and attach to the chromosomes — one microtubule per sister chromatid — at specialized link points called kinetochores. Like a rope, each microtubule is composed of multiple strands of tubulin, conferring stability to each spindle fiber.
Incidentally, how do these distant centrosomes know how many chromosomes there will be and come up with the right number of microtubules? I asked an AI engine that question. It said,
The centrosome doesn’t inherently “know” the number of chromosomes. Instead, the process of microtubule formation is guided by checkpoints in the cell cycle and regulatory proteins. During mitosis, each pair of chromosomes attaches to a kinetochore, which then attaches to the spindle fibers formed from the centrosome. The number of chromosomes determines the number of kinetochores, which in turn helps regulate the number of microtubules needed for proper chromosome separation. It’s a complex and coordinated process involving many proteins and regulatory mechanisms
OK, Well; Point Taken
Back to the “temporary meeting spaces” at centrosomes. The centrosome has no membrane. But when Cep57 (centrosome protein #57 out of dozens known so far) is present, a temporary barrier forms around the required ingredients. This happens by “liquid-lipid phase separation” (LLPS), something like how oil droplets form in water (see my previous article on condensates here). But first, the temporary meeting space (peri-centriolar matrix, or PCM) has to grow by an order of magnitude, from 300 nanometers to micrometers, as all the required ingredients assemble. “Human Cep57,” they say, “is a coiled-coil scaffold at the pericentriolar matrix (PCM), controlling centriole duplication and centrosome maturation for faithful cell division.”
Before the onset of mitosis, the centriole undergoes centriole-to-centrosome conversion by recruiting more centrosomal components and expanding the PCM into a micron-sized structure. This expansion leads to an increase in the microtubule nucleation factors, facilitating the rapid assembly of the mitotic spindle during mitosis. It is a central question of how the PCM assembles into a dense compartment enriched with hundreds of different proteins in the human centrosome during PCM expansion. Liquid–liquid phase separation (LLPS) is a compelling concept for elucidating the organizational principles underlying membrane-less organelles. In LLPS systems, multivalent interactions through folded domains or intrinsically disordered regions drive phase separation, resulting in the formation of dynamic biomolecular condensates accessible to cognate clients
“Hundreds of different proteins.” Did you catch that? How do the right ones all end up within the membraneless condensate? How could blind evolution ever accomplish such a meet-up? Interestingly, the “intrinsically disordered regions” of some of these proteins, which might have been considered poorly designed by some, play a key role in the phase separation. Notice, too, that the condensate is “dynamic” and “accessible” to the “cognate clients” that belong there, while keeping non-members out.
The authors point out that a deficiency of just this one component, Cep57, results in disorganization of the PCM, and a terrible disease:
Cep57 mutations are genetically linked to mosaic-variegated aneuploidy (MVA), a rare disease characterized by an abnormal number of chromosomes. The MVA syndrome manifests in various disorders, including skeletal anomalies, microcephaly, and childhood cancers
Cep57 is not the only vital part. “Cep57, Cep63, Cep152, Cep192, CDK5RAP2 (Cep215), and pericentrin are essential scaffolding proteins for PCM integrity.”
How’s Your Awe Meter So Far?
It’s difficult to convey the wonder of these realities without getting bogged down in jargon and detail. For more awe, add these considerations:
All this takes place in spaces too tiny to see with the naked eye.
Scientists have only discovered most of these intricate details within the lifetimes of many alive today.
The sequence of amino acids in each protein involved is far too improbable to have originated by chance.
Several million cells divide every second in our bodies.
Cells have been dividing since the beginning of life on earth.
The accuracy of cell division is so extraordinarily high, many animals alive today are recognizable from their counterparts in the fossil record.
We are truly privileged to behold details of wonders that were concealed from the eyes of people for thousands of years. If Romans and Babylonians and ancient Chinese were impressed by the sight of a baby at birth, how much more should we be awestruck, dumbfounded, indeed reverent at what biochemists are learning today about realities too small for human eyes? Sure, some observations like evil and suffering are hard to understand, yet even these are better situated for explanation in a design context. As my college biology prof used to say, “The amazing thing is not that we get sick. The amazing thing is that we are ever well,” considering how many things must work correctly each moment of every day. Never become complacent about these realities taking place inside us. We are witnessing intelligent design at a level never comprehended throughout all human history.
Sunday, 7 July 2024
Engineerless engineering ? :Cosmic edition.
From Galaxies to Atoms, a Vast Web of Fitness for Life
On a classic episode of ID the Future, host Eric Anderson begins a conversation with biochemist Michael Denton about Denton’s 2020 book The Miracle of the Cell, part of his continuing Privileged Species series exploring nature’s fine tuning for life. New research keeps unveiling ever more ways in which this fine tuning exists, from the cosmos to the atoms of the periodic table, and even to the subatomic level of quantum tunneling. Says Denton: “The miracle of the cell completes the overall fitness paradigm that unites galaxies with atoms in a vast web of fitness for life.”
Denton helped launch the modern intelligent design movement with his seminal 1985 book Evolution: A Theory in Crisis. The book inspired a number of well-known ID scholars, including Michael Behe, Stephen Meyer, and William Dembski, to speak out on the limits of Darwinian processes and the evidence for intelligent design. Denton followed up in 1998 with Nature’s Destiny, a step-by-step argument for human inevitability and human uniqueness in the universe.
This is Part 1 of a two-part conversation. Find and listen to the podcast here. Look for Part 2 next!
Saturday, 6 July 2024
Friday, 5 July 2024
Another Friday,another nightmare for Darwinists, courtesy the fossil record.
Fossil Friday: Time Wanderers Debunk Popular Scenario of Mammalian Evolution
This Fossil Friday features the holotype of the shrew-sized fossil vertebrate Chronoperates paradoxus from the Early Tertiary (Late Paleocene) Paskapoo Formation of Alberta in Canada. I still remember very vividly, when I was a graduate student at the University of Tübingen the sensational discovery of this fossil hit the news in 1992 (Hecht 1992, Novacek 1992), which we discussed in the vertebrate phylogeny course of the late great Dr. Gerhard Mickoleit. What was so special about this find?
In their original description of the tiny fossil jaw fragment, Fox et al. (1992a) documented several unique features of the lower jaw and its dentition that are exclusively characteristic of primitive mammal-like reptiles of the order Therapsida and the suborder Cynodontia (both taxa were later redefined in cladistic classification to include true mammals). Therapsids first appeared in the Early Permian 280 million years ago and were believed to have become extinct in the Middle Jurassic about 160 million years ago. Therefore, this Paleocene fossil would have been 100 million years younger than the previous youngest fossil record of therapsids and double their stratigraphic range, implying a long ghost lineage. This is why the relict genus was named Chronoperates, which means time wanderer in Greek.
Immediately Contested
The determination of Chronoperates as a therapsid was immediately contested by vertebrate paleontologist Hans-Dieter Sues (2006), but defended by the original authors (Fox et al. 1992b), who emphasized that Sues had not presented any synapomorphies in support of his alternative mammalian determination, and also had never studied the actual specimen. Indeed, the main argument by Sues was a very vague appeal to the only subtle differences between the teeth of Chronoperates and those of Cretaceous symmetrodont mammals (also see Novacek 1992), which was a possibility that was actually already addressed and refuted in the original description, as well as the false and misleading claim that the therapsid features could rather be artefacts of preservation. Nevertheless, some other scientists also doubted a therapsid affinity but explicitly admitted that they “don’t have any alternative to offer” (Hopson quoted in Hecht 1992). McKenna & Bell (1997: 43) likewise did not believe in the non-mammalian cynodont identity, but rather suggested a “dubious” position, possibly among basal holotherians, which are Triassic and Jurassic stem mammals (see Naish 2006b). Naish (2006b) also mentioned that “Meng et al. (2003) noted that the medial dentary scar seen in Chronoperates might not house post-dentary bones, as Fox et al. proposed, but instead a persisting Meckel’s cartilage. Now, if Chronoperates did possess a Meckel’s cartilage, this would be a first for a post-Mesozoic synapsid, and would further support ideas that Chronoperates is actually a late-surviving basal mammal” as suggested by McKenna & Bell.
Until today the therapsid affinity of Chronoperates is generally considered to be debunked, and Chronoperates is listed as potential symmetrodont mammal in Wikipedia, all based on a single one-page article with some unsubstantiated sweeping comments by a scientist, who never studied the actual fossil himself. Nobody ever bothered to look at this sensational fossil again. The only reason why the skeptical view still prevailed, is that the fossil would be very much out-of-place and contradicting the expectations from the mainstream Darwinian scenario of mammal origins. So much about unbiased scientific quest for truth. If some facts don’t fit the narrative, just deny them and sweep them under the rug.
Other Out-of-Place Fossils
In his two-part blog post, vertebrate paleontologist Darren Naish (2006a, 2006b) also discussed some other out-of-place fossils of mammal-like reptiles (non-mammalia therapsids):
In 1915 several fragmentary fossil bones were discovered in Early Cretaceous sediments from Queensland in Australia, which exhibited remarkable similarities with the extinct Dicynodontia, a clade of Permian and Triassic herbivore non-mammalian therapsids that lacked any fossil record beyond the Triassic-Jurassic boundary. The surprising dicynodont affinity was later indeed strongly confirmed by Thulborn & Turner (2003), who meticulously demonstrated that neither the dating nor the phylogenetic position can be reasonably disputed. This is a big deal, because this fossil record of dicynodonts is again “something like 100 million years younger than the previously known youngest members of the group” (Naish 2006a). This arguably proves that a similar ghost lineage for Chronoperates would be well within the realm of possibility and no reason to reject its determination as therapsid. So, it is hardly surprising that just a few years later, Agnolin et al. (2010) claimed that the Australian bones may rather have belonged to an extinct group of crocodyliforms called Baurusuchia, just because of unspecified striking similarities without any further explanation or documentation, while Knutsen & Oerlemans (2020) disputed the dating (instead suggesting a Plio-Pleistocene age) and the determination all-together, but this time the bones were claimed to belong to a diprotodontid marsupial and suddenly found “no features diagnostic of dicynodonts.” Thulborn & Turner (2003) on the other hand had unequivocally stated that this fossil “clearly does not represent … any of the big marsupials such as Diprotodon … The only identification supported by positive evidence, in the form of demonstrable similarities and diagnostic features, is ‘dicynodont.’” As happens all too often, apparently everything goes by the board when the goal is to make inconvenient fossils fit the preferred story. It is sobering to realize how dubious and sloppy evolutionary biology actually works when you look a bit closer behind the pompous facade of the so-called “undeniable scientific facts.”
Simpson (1928) described the docodont Peraiocynodon inexpectatus from the Early Cretaceous Purbeck Limestone of England, which was confirmed as a docodont by Averianov (2004). The species name inexpectatus of course alludes to the unexpected young age of this fossil, because Docodonta are Mesozoic mammaliaforms that abruptly appeared in the fossil record of the Middle Jurassic and were believed to have gone extinct in the Late Jurassic. Maschenko et al. (2002) described with Sibirotherium another late surviving docodont from the Early Cretaceous of West Siberia, later complemented by another genus Khorotherium from the Early Cretaceous of Yakutia as the youngest known docodont (Averianov et al. 2018). The previously described assumed docodont Reigitherium from the Late Cretaceous of Patagonia (Pascual et al. 2000), was later recognized as a real mammal of the dryolestoid order Meridiolestida (Rougier et al. 2003, 2011, Harper et al. 2018), which may well be correct.
Finally, there is the unnamed Saint Bathans mammal from the Early Miocene (18.7-15.9 mya) of New Zealand (Worthy et al. 2006), which is known from three fragmentary specimens and seems to represent a basal mammaliaform outside the crown group clade of monotremes, marsupial and placental mammals, and even basal of the extinct multituberculate branch. It is technically not a non-mammalian therapsid but also not a crown group mammal. Therefore, the discovery of such a primitive stem mammal in Miocene layers was highly unexpected and surprising (Naish 2006b).
Survivors or Relics
All these late survivors or relicts (sometimes called Lazarus taxa) are not just some weird scientific curiosities, but actually demonstrate a general problem with the common evolutionary narrative about mammalian origins, which claims that mammal-like reptiles disappeared because they were outcompeted by the modern true mammals. Mammal-like reptiles like pelycosaurs and therapsids ruled the Permian and Triassic periods, and some therapsids like the herbivorous Tritylodontidae existed till the Jurassic. All these alleged early ancestors of mammals were thought to have been wiped out by the more modern real mammals (Mammaliaformes), which originated in the Triassic but did not diversify before the Late Jurassic. This widely accepted replacement theory was overturned for good, when more than 250 tritylodontid teeth were discovered in Early Cretaceous layers of Japan (Matsuoka et al. 2016), proving that tritylodontids survived 30 million years longer than previously believed. Tritylodontids demonstrably coexisted for millions of years with more modern mammaliaforms that partly even occupied the same herbivorous niches. The crude Darwinist presumption of more advanced descendants outcompeting their primitive ancestors turned out to be wrong once again. The take-home message is this: Darwinian stories are exactly that — just fancy stories rooted in wishful thinking rather than in hard science.
References
Agnolin FL, Ezcurra MD, Pais DF & Salisbury SW 2010. A reappraisal of the Cretaceous non-avian dinosaur faunas from Australia and New Zealand: Evidence for their Gondwanan affinities. Journal of Systematic Palaeontology 8(2), 257–300. DOI: https://doi.org/10.1080/14772011003594870
Averianov AO 2004. Interpretation of the Early Cretaceous mammal Peraiocynodon (Docodonta) and taxonomy of some British Mesozoic docodonts. Russian Journal of Theriology 3(1), 1–4. https://zmmu.msu.ru/rjt/articles/ther3_1_01_04_Averianov.pdf
Averianov A, Martin T, Lopatin A, Skutschas P, Schellhorn R, Kolosov P & Vitenko D 2018. A high-latitude fauna of mid-Mesozoic mammals from Yakutia, Russia. PLoS ONE 13(7):e0199983, 1–17. DOI: https://doi.org/10.1371/journal.pone.0199983
Fox RC, Youzwyshyn GP & Krause DW 1992a. Post-Jurassic mammal-like reptile from the Palaeocene. Nature 358(6383), 233–235. DOI: https://doi.org/10.1038/358233a0
Fox RC, Youzwyshyn GP & Krause DW 1992b. Palaeocene therapsid debate. Nature 360, 540. DOI: https://doi.org/10.1038/360540a0
Harper T, Parras A & Rougier GW 2018. Reigitherium (Meridiolestida, Mesungulatoidea) an Enigmatic Late Cretaceous Mammal from Patagonia, Argentina: Morphology, Affinities, and Dental Evolution. Journal of Mammalian Evolution 26(4), 447–478. DOI: https://doi.org/10.1007/s10914-018-9437-x
Hecht J 1992. Science: Riddle of the ‘time wanderer’. NewScientist August 29, 1992. https://www.newscientist.com/article/mg13518363-300-science-riddle-of-the-time-wanderer/
Knutsen EM & Oerlemans E 2020. The last dicynodont? Re-assessing the taxonomic and temporal relationships of a contentious Australian fossil. Gondwana Research 77, 184–203. DOI: https://doi.org/10.1016/j.gr.2019.07.011
Maschenko EN, Lopatin AV & Voronkevich AV 2002. A new genus of tegotheriid docodonts (Docodonta, Tegotheriidae) from the Early Cretaceous of West Siberia. Russian Journal of Theriology 1(2), 75–81. DOI: https://doi.org/10.15298/rusjtheriol.01.2.01
Matsuoka H, Kusuhashi N & Corfe IJ 2016. A new Early Cretaceous tritylodontid (Synapsida, Cynodontia, Mammaliamorpha) from the Kuwajima Formation (Tetori Group) of central Japan. Journal of Vertebrate Paleontology 36(4): e1112289, 1–16. DOI: https://doi.org/10.1080/02724634.2016.1112289
McKenna MC & Bell SK 1997. Classification of Mammals Above the Species Level. Colombia University Press, New York (NY), xii+631 pp. https://books.google.at/books?id=zS7FZkzIw-cC
Meng J, Hu Y, Wang Y & Li C 2003. The ossified Meckel’s cartilage and internal groove in Mesozoic mammaliaforms: implications to origin of the definitive mammalian middle ear. Zoological Journal of the Linnean Society 138, 431–448. DOI: https://doi.org/10.1046/j.1096-3642.2003.00064.x
Naish D 2006a. ‘Dicynodonts that didn’t die: late-surviving non-mammalian synapsids I. Tetrapod Zoology May 23, 2006. http://darrennaish.blogspot.com/2006/05/dicynodonts-that-didnt-die-late.html
Naish D 2006b. ‘Time wandering’ cynodonts and docodonts that (allegedly) didn’t die: late-surviving synapsids II. Tetrapod Zoology May 25, 2006. http://darrennaish.blogspot.com/2006/05/time-wandering-cynodonts-and-docodonts.html
Novacek MJ 1992. Wandering across time. Nature 358(6383), 192. DOI: https://doi.org/10.1038/358192a0
Pascual R, Goin FJ, González P, Ardolino A & Puerta PF 2000. A highly derived docodont from the Patagonian Late Cretaceous: evolutionary implications for Gondwanan mammals. Geodiversitas 22(3), 395–414. https://sciencepress.mnhn.fr/en/periodiques/geodiversitas/22/3/un-docodonte-tres-derive-du-cretace-superieur-de-la-patagonie-implications-evolutives-pour-des-mammiferes-gondwaniens
Rougier G, Novacek MJ, Ortiz-Jaureguizar E, Pol D & Puerta P 2003. Reinterpretation of Reigitherium bunodontum as a Reigitheriidae dryolestoid and the interrelationships of the South American dryolestoids. Journal of Vertebrate Paleontology 23(Supp. 3), 90A. DOI: https://doi.org/10.1080/02724634.2003.10010538
Rougier GW, Apesteguía S & Gaetano LC 2011. Highly specialized mammalian skulls from the Late Cretaceous of South America. Nature 479 (7371), 98–102. DOI: https://doi.org/10.1038/nature10591
Simpson GG 1928. A Catalogue of the Mesozoic Mammalia in the Geological Department of the British Museum. British Museum (Natural History), London (UK), 215 pp.
Sues H-D 1992. No Palaeocene ‘mammal-like reptile’. Nature 359, 278. DOI: https://doi.org/10.1038/359278a0
Thulborn T & Turner S 2003. The last dicynodont: an Australian Cretaceous relict. Proceedings of the Royal Society of London B 270(1518), 985–993. DOI: https://doi.org/10.1098/rspb.2002.2296
Worthy TH, Tennyson AJD, Archer M, Musser AM, Hand SJ, Jones C, Douglas BJ, McNamara JA & Beck RMD 2006. Miocene mammal reveals a Mesozoic ghost lineage on insular New Zealand, southwest Pacific. PNAS 103(51), 19419–19423. DOI: https://doi.org/10.1073/pnas.0605684103
Thursday, 4 July 2024
The brain is more complex than the universe it contemplates?
Research: Our Brains Float Between Two Phases, Dodging Disorder
Anyone who has felt the need for several overflow brains just to keep up with a busy day will know the dread of a cartoon-like collapse. The good news, according to recent research, is that unsteadiness is the normal state of the human brain.
As science writer Carly Cassella puts it at ScienceAlert, “The human brain’s complexity verges on the brink of chaos, physicists say.” Our minds just never quite get used to it.
Poised Between Two Phases Without Collapsing
The physicists are Helen Ansell and István Kovács of the Physics and Astronomy Department at Weinberg College of Arts and Sciences at Northwestern University in Illinois. Examining the anatomy of neurons in the brains of humans, mice and fruit flies, they found that the cellular structure of the brain sits at a point that is poised between two phases:
When a magnet is heated up, it reaches a critical point where it loses magnetization. Called “criticality,” this point of high complexity is reached when a physical object is transitioning smoothly from one phase into the next…
Now, a new Northwestern University study has discovered that the brain’s structural features reside in the vicinity of a similar critical point — either at or close to a structural phase transition.
NORTHWESTERN UNIVERSITY. “BRAIN’S STRUCTURE HANGS IN ‘A DELICATE BALANCE,’” SCIENCEDAILY, 10 JUNE 2024. THE PAPER IS OPEN ACCESS.
The researchers don’t know whether this state is universal in brains as only three types have been studied so far.
Like Ice Becoming Water
No one has yet named the phases that the brains’ structures seem to hover between:
“The structure of the brain at the cellular level appears to be near a phase transition,” said Northwestern’s Helen Ansell, the paper’s first author. “An everyday example of this is when ice melts into water. It’s still water molecules, but they are undergoing a transition from solid to liquid. We certainly are not saying that the brain is near melting. In fact, we don’t have a way of knowing what two phases the brain could be transitioning between. Because if it were on either side of the critical point, it wouldn’t be a brain.”
NORTHWESTERN. ““A DELICATE BALANCE”
So how do the researchers know that these brains are near a phase transition?
Brain cells are arranged in a fractal-like statistical pattern at different scales. When zoomed in, the fractal shapes are “self-similar,” meaning that smaller parts of the sample resemble the whole sample. The sizes of various neuron segments observed also are diverse, which provides another clue. According to Kovács, self-similarity, long-range correlations and broad size distributions are all signatures of a critical state, where features are neither too organized nor too random. These observations lead to a set of critical exponents that characterize these structural features.
NORTHWESTERN. ““A DELICATE BALANCE”
Cassella offers
In the past, some scientists have suspected that phase transitions play an important role in biological systems. The membrane that surrounds cells is a good example. This lipid bilayer fluctuates between gel and liquid states to let proteins and liquid in and out.
By contrast, however, the central nervous system may teeter on a critical point of transition, while never actually becoming something else.
CARLY CASSELLA, SCIENCEALERT
Cassella’s comparison to the cell membrane is apt. Perhaps it will turn out that a slush environment is essential for a structure as complex as a brain. Forced into one phase only, it might start to malfunction.
The Human Brain Is a Lot Like the Universe
If we find these outcomes odd, it’s helpful to keep in mind that the human brain, for example, also has many similarities to the universe itself. Among others
Your brain is made up of a complex network of nearly 100 billion neurons that form 100 trillion neural connections. Neurons are clustered into a hierarchical network of nodes, filaments, and interconnected neural clusters that shape the complex thoughts, feelings, and emotions you experience. But these neurons make up less than 25 percent the mass of your brain, leaving the remaining 75 percent as water.
In a bizarre coincidence, the observable universe also contains an estimated 100 billion galaxies. The teetering balance between the pull of gravity and the accelerated expansion of the universe forms a cosmic web of string-like filaments composed of ordinary and dark matter.
TIM CHILDERS, “THE HUMAN BRAIN LOOKS SUSPICIOUSLY LIKE THE UNIVERSE, WHICH MAY FREAK YOU OUT,” POPULAR MECHANICS, NOVEMBER 17, 2020
Seen from that perspective, the brain’s delicate hover between two phases is just one of many remarkable facts about it.
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