Featuring six mammals that have body parts we would be more likely to associate with distant life forms:
Mammals have a pretty basic blueprint. Among other things, we give birth to live young, we’re warm-blooded, and, perhaps most obviously, we all have hair. (Yes, even dolphins.) But in the churn of natural selection, some mammals ended up with appendages that look like they should be found on a reptile, bird, or insect. That’s convergent evolution for you: Why should reptiles be the only ones to enjoy the protection of scales, or birds the benefits of webbed feet? This list is comprised of mammals who have clearly been taking pages from other playbooks.
Isaac Schultz, “6 Mammal Body Parts That Look Like They Were Stolen From Other Animals” at Gizmodo
But wait. “Natural selection,” as usually understood, assumes ancestor-descendant relationships. That’s the point of it. If mammals “have clearly been taking pages from other play books,” how exactly, were they able to do so?
Here’s an item from 2015 on the prevalence of convergent evolution: Evolution appears to converge on goals—but in Darwinian terms, is that possible?
And, as I’ve noted before, the welter of data coming back from paleontology, genome mapping, and other studies are changing paleontology from a discipline dependent on grand theories to one more like human history, dependent on identified facts.
A century or so ago, British anatomist St. George Mivart noted that Darwin’s theory of evolution “does not harmonize with closely similar structures of diverse origin” (convergent evolution). There is more evidence for Mivart’s doubts now than ever.
According to current Darwinian evolutionary theory, each gain in information is the result of a great many tiny, modest gains in fitness over millions or billions of years, due to natural selection acting on random mutations. The resulting solutions should then follow inheritance laws, in the sense that the more similar life forms are according to biological classifications, the more similar their genome map should be.
That just did not work out. Different species can have surprisingly similar genes. For example, kangaroos are marsupial mammals, not placentals. Yet their genes are close to humans. Researchers: “We thought they’d be completely scrambled, but they’re not.”
Kangaroos? Shark and human proteins, meanwhile, are also “stunningly similar.” Indeed, sharks are genetically closer to humans than they are to aquarium zebrafish. Researchers: “We were very surprised… “
Sharks? But does all this not raise a serious question? The popular science literature claims that a near identity between the human and chimpanzee genome is irrefutable evidence of common descent. Why then do we hear so little about any of these findings, which muddy the waters? Why are science writers not even curious?
There is also the question of how easily a life form can “evolve” a complex solution to a difficult problem. Birds are said to have evolved ultraviolet vision at least eight times.
Similarly, whether large bird and mammal brains arise from common descent or convergent evolution is actually uncertain. Two distantly related groups of reptiles are thought to have given rise to mammals and birds, both featuring a much higher brain to body weight ratio than in their ancestors. Paleontologist R. Glenn Northcutt writes that the matter is “contentious and unresolved,” because brains rarely fossilize.
It’s not just mammals and birds. Two different species of deadly sea snake, with “separate evolutions,” were found to be identical. Dolphins and insects, we are told, share components of a hearing system.
The smartest invertebrates, the molluscs (including squid, octopuses, and cuttlefish), seem to have evolved brains four times. From one study we learn, “The new findings expand a growing body of evidence that in very different groups of animals — and mammals, for instance — central nervous systems evolved not once, but several times, in parallel.”
Cambridge paleontologist Simon Conway Morris’s Map of Life website provides many other examples of convergence, listing, for example, the convergent evolution of foul smelling plants (“Love me, I stink”), convergence in sex (love-darts), eyes (camera-style eyes in jellyfish), agriculture (in ants) or gliding (in lizards and mammals).
Convergent evolution is evidence that evolution can happen. But the Darwinian model does not seem to be the right one. The life forms appear to be converging on a common goal.
It’s a good thing some science writers are at last becoming curious.
Here’s the starnosed mole, featured in the slideshow and probably the one that reminds one, sort of, of an insect:
See also: Reformed New Scientist: Covering all the ways evolution can happen and treating Darwinism with… a certain caution.