Dawn of the Picasso Fish

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.