A gene responsible for the development of fins in a primitive fish also helped shape the hands, feet and wings of every land animal alive today.
The finding, to be detailed in an upcoming issue of the Journal of Experimental Zoology, adds to growing evidence that digits in humans and other land creatures are the equivalent of fin bones in fish. It is yet another example of evolution tweaking what already works to generate novel traits.
Because of the similarities, we can say that fish fins have similar structures to tetrapod digits, [and that] tetrapod digits are no longer unique to the group.
And because whales and birds descended from creatures with fingers and toes—hoofed mammals and dinosaurs, respectively—their flippers and wings are also evolutionarily linked to fish fins!
Kemo D. (a.k.a. no.7) www.beyondgenes.com