Carl Zimmer gives a typically fascinating account of the evolution of our understanding of how the flatfish came to have two eyes on one side of its head, an evolutionary conundrum that engaged both Charles Darwin and his critics. Darwin argued that the trait evolved over many generations of flatfish; however there was no evidence for this morphological development in the fossil record.The most recent contribution to the story is evolutionary biologist Matt Friedman’s discovery of three examples of transitional forms of flatfish among the dusty fossil collections of Europe. What is most interesting to me is that these fossils were long ago collected and curated, but so clearly satisfy the requirement of a Darwinian intermediate. Matt Friedman explains:
I suppose there is a general perception that museum collections are dusty, static archives, and that everything in them has been carefully studied and precisely identified. But the truth is that they are much more than just long-term storage, because as our interpretive framework matures, we can begin to make sense of specimens that evaded or baffled earlier generations of researchers, or draw new conclusions about materials we mistakenly thought we had figured out ages ago.
