speciation

British physicist David Tyler discusses the recent claims for the possibility of new species of finch developing on the famous Galapagos Islands – a possibility because the authors don’t think they are there yet, and they may never be. Tyler explains,

An ecological theory of speciation but no support for Darwinism

The Galapagos Islands have long been recognised as the home of numerous endemic species, stimulating questions about how such species came into being. Those responding with answers have supported their views more by theory than observation. But Peter and Rosemary Grant are different, because they have pioneered longitudinal studies of the Galapagos finches, particularly on the small (and relatively isolated) island of Daphne Major. A newly reported study of an immigrant male ground finch (Geospiza fortis) covers the period 1981 to the present. “We have followed the survival and reproduction of this individual and all of its known descendants, here termed the immigrant lineage, for seven generations (F0 to F6) spanning 28 years.”

The bird sings differently (maybe better, if you are a hen finch). Tyler goes on to note,

Science reports of stories relevant to evolutionary theory can degenerate to the level of cheer-leading for a favoured cause. One account of the Grants’ research refers to “a real-time record of evolution in action. In the PNAS paper, they describe something Darwin could only have dreamed of watching: the birth of a new species.” For more, please refer to Jonathan Wells’ comments here.

The problem is that speciation of this type is just as likely to reverse itself when the ecology changes. Go here for the rest.

Note: For that matter, too easy speciation can lead to extinction of species. Read More ›

At Wired Science, we are informed “Birth of New Species Witnessed by Scientists” (November 16, 2009):

On one of the Galapagos islands whose finches shaped the theories of a young Charles Darwin, biologists have witnessed that elusive moment when a single species splits in two.

In many ways, the split followed predictable patterns, requiring a hybrid newcomer who’d already taken baby steps down a new evolutionary path. But playing an unexpected part was chance, and the newcomer singing his own special song.

My best guess is that if the girls stop dropping by, he will soon be either singing a different tune or a bachelor. Note the qualifications:

The future of the species is far from certain. It’s possible that they’ll be out-competed by other finches on the island. Their initial gene pool may contain flaws that will be magnified with time. A chance disaster could wipe them out. The birds might even return to the fold of their parent species, and merge with them through interbreeding.

But whatever happens, their legacy will remain: New species can emerge very quickly — and sometimes all it takes is a song.

Hmmm. Read More ›