Re: Galapagos finches - new species
Interesting story. (Thanks, Landroid) The Galapagos Islands seem to present ideal circumstances under which speciation can occur. The similarities between different kinds of finches make it obvious that speciation does occur. But it seems fairly obvious that even species that diverged a little further back in time are also closely related (like dogs and foxes or apes and monkeys), and we need not fixate on having observed speciation "directly". We didn't see the Grand Canyon being formed either, but we have a pretty good idea how it happened.
Anyway, I'm not sure that we've never observed speciation directly before:http://www.darwinwasright.org/observati ... ation.html
I was recently reading about the Carolina Chickadee (a bird that hangs out at our bird feeder). It looks very much like a Black-capped Chickadee that lives more to the north. Both Carolina and Black-capped chickadees hybridize in the area where their ranges overlap, but they are otherwise considered two different species, believed to have diverged more than 2.5 million years ago. The zone where they do interbreed is is narrow ribbon only 20 miles wide.
Physically the two species are almost identical, but each differs in some of its habits. Even more interesting (to me) is that the songs of the two birds are different. As such this speciation of chickadees in the United States (and Canada) is quite similar to what's being observed with the finches on the Galapagos Islands. The big difference is that the birds in United States are not separated by water.http://www.audubon.org/news/identifying ... chickadees