Michael J. Behe's Blog, page 111

February 4, 2022

Did low oxygen levels limit evolution for billions of years?

Probably, but here is an interesting proposed timestamp:

When did the Earth reach oxygen levels sufficient to support animal life? Researchers from McGill University have discovered that a rise in oxygen levels occurred in step with the evolution and expansion of complex, eukaryotic ecosystems. Their findings represent the strongest evidence to date that extremely low oxygen levels exerted an important limitation on evolution for billions of years.

“Until now, there was a critical gap in our understanding of environmental drivers in early evolution. The early Earth was marked by low levels of oxygen, till surface oxygen levels rose to be sufficient for animal life. But projections for when this rise occurred varied by over a billion years — possibly even well before animals had evolved,” says Maxwell Lechte, a postdoctoral researcher in the Department of Earth and Planetary Sciences under the supervision of Galen Halverson at McGill University.

McGill University, “What the rise of oxygen on early Earth tells us about life on other planets” at ScienceDaily (January 31, 2022)

The researchers studied iron-rich sedimentary rocks across the globe:

“These ironstones offer insights into the oxygen levels of shallow marine environments, where life was evolving. The ancient ironstone record indicates around less than 1 % of modern oxygen levels, which would have had an immense impact on ecological complexity,” says Changle Wang, a researcher at the Chinese Academy of Sciences who co-led the study with Lechte.

“These low oxygen conditions persisted until about 800 million years ago, right when we first start to see evidence of the rise of complex ecosystems in the rock record. So if complex eukaryotes were around before then, their habitats would have been restricted by low oxygen,” says Lechte.

McGill University, “What the rise of oxygen on early Earth tells us about life on other planets” at ScienceDaily (January 31, 2022)

Hmm. Last night, we were noting researchers who think they can identify chromosomes from 800 million years ago so that fits.

Sounds like a system unrolling…

The paper is closed access.

You may also wish to read: Researchers: Moons make planets habitable — but not all planets can have them. University of Rochester: The researchers found that rocky planets larger than six times the mass of Earth (6M) and icy planets larger than one Earth mass (1M) produce fully—rather than partially—vaporized disks, and these fully-vaporized disks are not capable of forming fractionally large moons.

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Published on February 04, 2022 07:26

February 3, 2022

Researchers think they know how chromosomes came to exist

Starting 800 million years ago:

Chromosomes, the bundles of DNA that star in the mitotic ballet of cell division, play a leading role in complex life. But the question of how chromosomes came to exist and evolve has long been discouragingly hard to answer. This is due partly to the lack of chromosome-level genomic information and partly to the suspicion that eons of evolutionary change have washed away any clues about that ancient history.

Now, in a paper appearing today in Science Advances, an international team of researchers led by Daniel Rokhsar, a professor of biological sciences at the University of California, Berkeley, has tracked changes in chromosomes that occurred as much as 800 million years ago. They identified 29 big blocks of genes that remained recognizable as they passed into three of the earliest subdivisions of multicellular animal life. Using those blocks as markers, the scientists deduced how the chromosomes fused and recombined as those early groups of animals became distinct.

The researchers call this approach “genome tectonics.” In the same way that geologists use their understanding of plate tectonics to make sense of the appearance and movement of continents, these biologists are reconstructing how various genomic duplications, fusions and translocations created the chromosomes we see today.

Viviane Callier, “Secrets of early animal evolution Revealed by Chromosome ‘Tectonics’” at Quanta (February 2, 2022)

Okay, but all this information exploding all of a sudden such a long time ago… ?

The paper is open access.

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Published on February 03, 2022 19:20

At Mind Matters News: Neuroscientists: The Hard Problem of consciousness isn’t so hard!

Neuroscientists Antonio Damasio and Anil Seth tell Nautilus that materialist explanations will eventually crack consciousness, as they have cracked everything else:

A reader might come away from this discussion with the following observations:

● We all know that we are conscious; it is the one thing of which we are most sure, as analytical philosopher Galen Strawson has pointed out.

● It’s not strictly true that “Every bit of evidence we have is that the mysteries of the universe have been gradually solved by science” (Damasio). While science is making headway with many mysteries, others (origin of life, for example, or the origin of the Cambrian Explosion) remain opaque.

● While Damasio and Seth seem convinced that materialist “science” will explain consciousness, it’s not clear that they are anywhere close — though they have certainly learned some interesting things about the workings of the brain. That attitude is often called promissory materialism: “Just you wait and materialism will solve this problem.”

As the problem remains unsolved, we are entitled to conclude, provisionally, that consciousness is not a material phenomenon and that that is why materialism-based methods don’t work.

But don’t expect Damasio, Seth, or their successors to take that lying down. Too much is at stake philosophically.

News, “Neuroscientists: The Hard Problem of consciousness isn’t so hard!” at Mind Matters News

Takehome: If consciousness remains unexplained by materialist theories, we are entitled to conclude, at least provisionally, that it is not a material phenomenon.

You may also wish to read: Consciousness is destroying physicalism Materialism (physical stuff is all there is) is taking a well-deserved beating of late. There is no basis in mere physics for what every human being absolutely knows: Our own consciousness.

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Published on February 03, 2022 18:50

Templeton is trying to have agency, directionality, and function in life forms without underlying intelligence

Kind of like giving a monkey a computer and hoping he’ll “get it” on his own:

There is a growing recognition that biological phenomena which suggest agency, directionality, or goal-directedness demand new conceptual frameworks that can translate into rigorous theoretical models and discriminating empirical tests. This project addresses the demand through a novel, interdisciplinary, large-scale program that combines philosophers, theoreticians, and experimentalists.

Introduction, “Biologists often attribute purpose to living systems… Should they?” at Agency, Directionality & Function

Here’s the blog.

A friend says a number of interesting Third Way people are there. No ID folk, of course.

It’s a good thing theTempleton-funded project is going to a great deal of trouble to demonstrate that intelligence does not create itself by — in effect — ruling out other possibilities via their work. Let’s wish them well at that.

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Published on February 03, 2022 17:16

Lockdowns Accomplished Nothing

I blew it when I predicted in 2020 that the Covid scare would be like the many scares before it, much hyped but not nearly as deadly as the fear mongers suggested it would be. But I was spot on when I pushed back against the lockdown being pushed by the Imperial College London crowd (which recommendations were ultimately adopted by most nations). So concludes a new paper out of Johns Hopkins University, “A Literature Review and Meta-Analysis of the Effects of Lockdowns on COVID-19 Mortality,”

As summarized in National Review, the “paper starts by noting that “an often cited model simulation study by researchers at the Imperial College London (Ferguson et al. (2020)) predicted that a suppression strategy based on a lockdown would reduce COVID-19 mortality by up to 98%.” The Imperial College simulation was among the sources used by public-health authorities to justify the earliest lockdowns. It turned out to be more than 98 percent wrong. According to the authors, the most-precise studies found no statistically significant effect of lockdowns on mortality.”

Countless trillions of dollars were wasted, millions of lives were impoverished, and the education of an entire generation was undercut. All for nothing. Will we keep that in mind the next time the government screams “follow the science”? Here’s another prediction. Probably not. I fear we have become a nation of hyper risk adverse (and therefore deeply compliant) sheep-le.

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Published on February 03, 2022 11:33

Sea spiders as a remarkable example of stasis: 450 million years?

Found in all oceans, these pycnogonids are not actually spiders, though most have eight legs.

About 1,300 species of sea spiders have been identified, and more are found every year. Fossils suggest that they’ve existed on Earth for at least 450 million years. Back then, pycnogonids and other arthropods likely dominated the oceans. Few animals lived on land.

Sea spiders lack organs for breathing, instead expelling carbon dioxide and taking in oxygen directly through their outer layer, or cuticle. This gas exchange primarily occurs via the legs, as they have the most surface area by far. Even more fascinating, it seems that pycnogonids primarily transport oxygen within their bodies via peristalsis, involuntary constriction and relaxation of the gut. Peristalsis moves hemolymph, or blood, throughout the body. “Shared digestive and respiratory functions may save energy,” the researchers who uncovered this strategy said. “Legs function as the gills used by other arthropods, and the gut functions as a heart.”

Ross Pomeroy, “The Strange, Unsettling World of Sea Spiders” at RealClearScience (February 2, 2022)

Their biology doesn’t sound like it would work — yet no big changes seem to have been needed for nearly half a billion years.

Pomeroy also notes,

As far as reproduction goes, males carry fertilized eggs then care for offspring. Females produce and lay eggs, which males then externally fertilize. Subsequently, males pick them up and store them with specialized body parts called ovigers.

Ross Pomeroy, “The Strange, Unsettling World of Sea Spiders” at RealClearScience (February 2, 2022)

That’s a complex sort of behavior, isn’t it? Unfortunately, we can’t know if it is an ancestral behavior or a recently developed one. But if there is no design in nature, how would it have developed at all? There is no clear path via random mutations.

and

You may also wish to read: Stasis: Life goes on but evolution does not happen

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Published on February 03, 2022 07:09

February 2, 2022

At Mind Matters News: How do insects use their very small brains to think clearly?

How do they engage in complex behavior with only 100,000 to a million neurons?:

Another strategy, one that enables social insects to engage in complex behaviors, is an established but little understood concept: The colony can have a memory that individual insects don’t have. Stanford biology prof Deborah M. Gordon, author of Ant Encounters: Interaction Networks and Colony Behavior (2010), recounts an experiment she did, to create an obstacle for ants and see if they remembered it.

Surprisingly,

I put out toothpicks that the workers had to move away, or blocked the trails so that foragers had to work harder, or created a disturbance that the patrollers tried to repel. Each experiment affected only one group of workers directly, but the activity of other groups of workers changed, because workers of one task decide whether to be active depending on their rate of brief encounters with workers of other tasks. After just a few days repeating the experiment, the colonies continued to behave as they did while they were disturbed, even after the perturbations stopped. Ants had switched tasks and positions in the nest, and so the patterns of encounter took a while to shift back to the undisturbed state. No individual ant remembered anything but, in some sense, the colony did.

Colonies live for 20-30 years, the lifetime of the single queen who produces all the ants, but individual ants live at most a year. In response to perturbations, the behaviour of older, larger colonies is more stable than that of younger ones. It is also more homeostatic: the larger the magnitude of the disturbance, the more likely older colonies were to focus on foraging than on responding to the hassles I had created; while, the worse it got, the more the younger colonies reacted. In short, older, larger colonies grow up to act more wisely than younger smaller ones, even though the older colony does not have older, wiser ants.

DEBORAH M. GORDON, “AN ANT COLONY HAS MEMORIES THAT ITS INDIVIDUAL MEMBERS DON’T HAVE” AT AEON (DECEMBER 11, 2018)

So some of the ways insects make the most of a few neurons are: specialized neurons, neurons focused on specific critical functions, and outsourcing memory issues to the colony as a whole.

News, “How do insects use their very small brains to think clearly?” at Mind Matters News

Takehome: Researchers are finding that insects have a number of strategies for making the most of comparatively few neurons to enable complex behavior.

You may also wish to read: In what ways are spiders intelligent? The ability to perform simple cognitive functions does not appear to depend on the vertebrate brain as such.

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Published on February 02, 2022 19:21

The remarkable process of cell division

A classic in design in nature:

Chromosomes are densely packed DNA. The two “sister chromatids” of a chromosome, having been accurately duplicated during prophase and secured by centromeres, are arranged with all the other chromosomes on the spindle axis in metaphase. Soon after they are winched apart in anaphase into daughter cells. This elaborate choreography takes place every time a cell divides. The cell cycle is fascinating to anyone who has witnessed it under a light microscope, as you can see here:

Evolution News, “DNA Packing: One of the Supreme Wonders of Nature” at Evolution News and Science Today (January 31, 2022)

Remarkable movies made with super-resolution atomic force microscopy show the parts of cohesin undergoing conformational changes. These hand-over-hand motions operate in the dark without eyes, using ATP for energy. They get it right every time!

Evolution News, “DNA Packing: One of the Supreme Wonders of Nature” at Evolution News and Science Today (January 31, 2022)

The paper is open access.

You may also wish to read: Everything is coming up non-random (PAV)

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Published on February 02, 2022 19:06

At Scientific American: Salamander “junk DNA” challenges long-held view of evolution

One salamander is a very unusual life form:

View the animal up close, and another oddity becomes apparent: its cells are up to 300 times larger than those of a lizard, bird or mammal. You can see, with a simple magnifying glass, individual blood cells zipping through the capillaries in its transparent gills.

The Neuse River waterdog, Necturus lewisi, and other salamanders represent a long-standing conundrum scientists are only now starting to understand. The animal’s strange traits stem from a hidden burden: Each of its cells is bloated with 38 times more DNA than a human cell. The waterdog has the largest genome of any four-footed beast on Earth. The only comparable animals of any kind are lungfish, which also have sluggardly tendencies.

Douglas Fox, “Junk DNA Deforms Salamander Bodies” at Scientific American (February 1, 2022)

They have, we are told, 10 billion to 120 billion base pairs because, it is thought, parasitic DNA has multiplied out of control. They live a slow, dull life and can live about 100 years. They can regenerate not only limbs but brain parts.

And the challenge for evolution?

As for salamanders, one has to wonder why their burden hasn’t dragged them down to extinction. Their very perseverance suggests that our idea of evolution, particularly “survival of the fittest,” has a serious moralistic bias: Work hard, young species, hone your body and brain for high performance, and someday you will succeed. But salamanders owe their success to lying around. They have found a way to cheat the system…

The salamanders would be on death’s door if they were human. “Everything about having a large genome is costly,” Wake told me in 2020. Yet salamanders have survived for 200 million years. “So there must be some benefit,” he said. The hunt for those benefits has led to some heretical surprises, potentially turning our understanding of evolution on its head…

These bloated beasts have demonstrated, time and again, that when it comes to survival of the fittest, our notion of “fitness” is biased toward strength and agility. Genomic parasites have slowed the waterdog’s development, swelled its cells and distorted its anatomy. This odd circumstance has pushed the animal onto a bizarre evolutionary side track that redefines fitness in such a way that hearts and complex brains are reduced to an afterthought. Yet somehow the animal’s lineage persists, even as fires, floods and asteroids obliterate other species—furry, feathered and scaled—that seem more fit.

Douglas Fox, “Junk DNA Deforms Salamander Bodies” at Scientific American (February 1, 2022)

This isn’t schoolbook natural selection, that’s for sure.

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Published on February 02, 2022 18:36

February 1, 2022

Researchers: Moons make planets habitable — but not all planets can have them

It’s an instance of fine-tuning:

Earth’s moon is vitally important in making Earth the planet we know today: The moon controls the length of the day and ocean tides, which affect the biological cycles of lifeforms on our planet. The moon also contributes to Earth’s climate by stabilizing Earth’s spin axis, offering an ideal environment for life to develop and evolve.

Because the moon is so important to life on Earth, scientists conjecture that a moon may be a potentially beneficial feature in harboring life on other planets. Most planets have moons, but Earth’s moon is distinct in that it is large compared to the size of Earth; the moon’s radius is larger than a quarter of Earth’s radius, a much larger ratio than most moons to their planets. p1 Miki Nakajima, an assistant professor of earth and environmental sciences at the University of Rochester, finds that distinction significant. And in a new study that she led, published in Nature Communications, she and her colleagues at the Tokyo Institute of Technology and the University of Arizona examine moon formations and conclude that only certain types of planets can form moons that are large in respect to their host planets…

The researchers found that rocky planets larger than six times the mass of Earth (6M) and icy planets larger than one Earth mass (1M) produce fully—rather than partially—vaporized disks, and these fully-vaporized disks are not capable of forming fractionally large moons.

University of Rochester, “Moons may yield clues to what makes planets habitable” at Phys.org (February 1, 2022)

The paper is open access.

You may also wish to read: What becomes of science when the evidence does not matter?

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Published on February 01, 2022 19:27

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