Evolution Intelligent Design

Reptiles evolved, de-evolved, re-evolved teeth

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Like a revolving door rather than any kind of straightforward evolution pathway, according to recent research:

Researchers at the Universities of Helsinki and Lyon and the Geological Survey of Finland found that complex teeth, a hallmark of mammals, also evolved several times in reptiles, prompting the evolutionary success of plant-eating lizards. However, contrary to mammals their tooth evolution was not unidirectional.

The study, published in Nature Communications, reveals that several lizard groups evolved teeth with multiple tips (“cusps”) that allowed new plant-based diets and higher speciation rates — that is, how fast new species appear. Surprisingly, tooth evolution was more flexible in lizards and snakes than mammals, revealing a more nuanced view of tooth and dietary evolutionary adaptations in vertebrates…

The team also found that complex teeth and plant consumption provided an evolutionary advantage, as both traits favoured the appearance of new species. However, many lizard lineages also lost complex teeth to re-evolve the ancestral simple tooth morphology. “This came as a complete surprise,” says PhD candidate Fabien Lafuma from the University of Helsinki, “as complex teeth appear as a critical innovation for both squamates and mammals.”…

Contrary to mammals, tooth evolution was not unidirectional, and numerous lineages reduced complexity over time.

University of Helsinki, “Plant-eating lizards on the cusp of tooth evolution” at ScienceDaily (October 15, 2021)

In short, when researchers actually looked at reptile tooth history, it was hardly a simple evolution tale at all. It seems as if there are plans that life forms can access, perhaps within their genomes. But how do they trigger the needed changes, as opposed to just going extinct?

The paper is open access.

5 Replies to “Reptiles evolved, de-evolved, re-evolved teeth

  1. 1
    Querius says:

    This discovery marks an evolving away from the Evolutionary Tree of Life in the direction of an Evolutionary Football Play Diagram model.

    – Or maybe genes are infectious between species . . .
    – Or maybe something in junk DNA flips a switch where teeth appear and disappear . . .
    – Or maybe genes blend together as in the platypus or a possible future plague of “piranhakeets” . . .

    This is so much fun.

    -Q

  2. 2
    polistra says:

    “How do they trigger the needed changes?”
    EXCELLENT question!

    Actually the known mechanisms of epigene control have a partial answer. At least in nematodes, epigenes in the offspring are varied under direct control of the mother’s nervous system. There’s a neuronal output into the egg. So the choice is being made intelligently. But this still leaves the more basic design question, how this mechanism itself came into being.

  3. 3
    Querius says:

    Yeah, exactly.

    How do epigenetic switches evolve. There are researchers who claim there are over a dozen overlapping (19?) epigenetic codes. If true, this makes them highly vulnerable to mutations in DNA. How did the codes themselves evolve?

    This is all mind blowing.

    I’m also reminded of insect metamorphosis where an insect dissolves its body and then reforms a different body. Or how certain organisms, including mosses and sea jellies and support life cycles called “alternation of generations” (N and 2N) between their gametes and zygotes.

    Consider a type of venomous organism that can range in size from a tiny grain of sand to something longer than a blue whale . Supposedly, it hasn’t evolved over 500 million years and cells from the originals may still be alive today. It uses a distributed neural network to react to its environment, can have eyes that range from simply detecting light and dark to human-like eyes that can detect colors, sizes, and shapes to avoid collisions or move toward prey. Behold the amazing Cnidaria, the mother of all living fossils.

    Or maybe it evolved and re-evolved thousands of times. Who knows. Darwinism is so magical that it can rationalize everything, yet predict nothing.

    -Q

  4. 4
    Querius says:

    Consider a type of venomous organism that can range in size from a tiny grain of sand to something longer than a blue whale . Supposedly, it hasn’t evolved over 500 million years and cells from the originals may still be alive today. It uses a distributed neural network to react to its environment, can have eyes that range from simply detecting light and dark to human-like eyes that can detect colors, sizes, and shapes to avoid collisions or move toward prey. Behold the amazing Cnidaria, the mother of all living fossils.

    C’mon, Darwinists! I’d love to hear a story about how evolution musta bypassed Cnidaria for hundreds of millions of years, and why their cells are immortal and our cells aren’t.

    -Q

  5. 5
    Querius says:

    Still waiting . . . (crickets)

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