Just coming into its own as a science, evo-devo is the combined study of evolution and development, the process by which a nubbin of a fertilized egg transforms into a full-fledged adult. And what these scientists are finding is that development, a process that has for more than half a century been largely ignored in the study of evolution, appears to have been one of the major forces shaping the history of life on earth.There are two excellent articles on evo-devo:
For starters, evo-devo researchers are finding that the evolution of complex new forms, rather than requiring many new mutations or many new genes as had long been thought, can instead be accomplished by a much simpler process requiring no more than tweaks to already existing genes and developmental plans. Stranger still, researchers are finding that the genes that can be tweaked to create new shapes and body parts are surprisingly few. The same DNA sequences are turning out to be the spark inciting one evolutionary flowering after another
From a few genes, life's myriad shapes and Darwin still rules, but some biologists dream of a paradigm shift, where the latter talks about possible future directions of evolutionary studies, including evo-devo. If you don't have time to read these and like pretty pictures, here is a very nice 5-minute video introduction to evo-devo - especially check out the bit on icefish.