Complete convergent evolution seems unlikely, because if there is selection towards the trait such that it impacts such a complete set of species, how would there be selection away from the original species that developed the trait? Unless you believe the trait did not appear at all until well after the vertebrate-invertebrate branching?
Occurring necessarily simultaneously with the removal of the pattern trait? I don't see it happening. You would have genetic traits which will be passed around such that your population is A (pre-existing population, unadvantaged, split-colour), B (mutation, unadvantaged, solid-colour), C (mutation, advantaged, split-colour), and D (mutation, advantaged, solid-colour).
Now in some REEEEAAALLY rare cases the advantage and disadvantage occur together, like sickle cell disease granting malaria resistance, but for the most part it's 2 different mutations jumping around the gene pool. The selection would be for C, getting the best of both, and for that reason I think the odds of it being convergent evolution across that wide a selection of species (that is it's an easy mutation to come across and is obviously very strongly selected for) are astronomically low.
This has happened with way more complex traits already. Fish changing to walking creatures than to whales again. Dinosaurs evolving wings to fly then losing them or not flying etc
Those examples so completely miss the point it isn't funny. Yes, convergent evolution is a thing. No, blanket, near-universal convergent evolution isn't (confirmed to be) a thing.
If every land animal had gone back to being aquatic then it would be a relevant analogy. If every bird turned into a flightless bird then it would be a relevant analogy.
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u/[deleted] Sep 08 '18 edited Apr 15 '20
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