Researchers were surprised when sauropterygians with very different lifestyles had evolved inner ears that were very similar to those of some modern animals.
“Sauropterygians are completely extinct and have no living descendants,” said Dr James Neenan, lead author of the study. “So I was amazed to see that nearshore species with limbs that resemble those of terrestrial animals had ears similar to crocodylians, and that the fully-aquatic, flippered plesiosaurs had ears similar to sea turtles.”
The similarities don’t end there. Some groups of plesiosaurs, the ‘pliosauromorphs’, evolved enormous heads and very short necks, a body shape that is shared by modern whales. Whales have the unusual feature of highly miniaturized inner ears (blue whales have a similar-sized inner ear to humans), possibly the result of having such a short neck. Neenan and colleagues have now shown that ‘pliosauromorph’ plesiosaurs also have a reduced inner ear size, supporting this idea.
These interesting results are the product of convergent evolution, the process in which completely unrelated organisms evolve similar solutions to the same evolutionary hurdles. Paper. (paywall) – James M. Neenan, Tobias Reich, Serjoscha W. Evers, Patrick S. Druckenmiller, Dennis F.A.E. Voeten, Jonah N. Choiniere, Paul M. Barrett, Stephanie E. Pierce, Roger B.J. Benson. Evolution of the Sauropterygian Labyrinth with Increasingly Pelagic Lifestyles. Current Biology, 2017; DOI: 10.1016/j.cub.2017.10.069 More.
Evolution is more interesting when we leave Darwin out of it.
See also: Convergent evolution?: After millions of years of evolution, bamboo lemurs share 48 gut microbes with giant pandas and red pandas But share only eight gut microbes with their closely related cousins, the ringtail lemurs. This is not a neat Darwinian picture. Findings like this offer a caution flag for sweeping generalizations based on ancestry. Ancestry may not be as important as we think in evolution.
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