Newly evolved finch appears on the Galapagos Islands
Posted by Jimalakirti in Evolution
at 9:16 am on Thursday, 17 December 2009
at 9:16 am on Thursday, 17 December 2009
Evolution caught in the act? An isolated population of finches have odd-shaped beaks, sing differently, and don’t breed with others.
Just a few years ago, the husband and wife team of Peter and B. Rosemary Grant made the breakthrough discovery that the beak sizes of some of the finches on the Galapagos Islands had already changed since Darwin’s visit in 1835. Now they believe they may have witnessed the evolution of a brand new species.
(Mother Nature Network, November 16, 2009)
This is a very exciting article. The Grants first noticed that a larger finch from another island had arrived, and its children had a different beak and a different song from the mother bird’s family. They observed this line through seven generations. During this time a drought reduced the population of these “mutant” birds to two, a brother and a sister. Since that time they have refused to breed with the original species.
The scientists do not claim to have seen speciation yet. How many generations of separation are required before we call the family a new species?
This is a good piece of popular scientific writing. The authors anticipate and answer some of the most likely objections that might arise. (Some valuable information that strengthens this article is in the links to outside information. It is a good idea to follow up links if the author offers them to you. Often the author will take what was in a link for granted, thinking he said it himself. (Or at least old men like myself do that.)
An excellent observation by the team of Rosemary & Peter Grant. This couple has been studing natural selection among finches on the small island of Daphne Major for at least 30 years. The Pulitzer Prize winning book,THE BEAK OF THE FINCH published in 1993 and written by Jonathan Weiner is a gem and a must read for anyone interested in evolution and in particular anyone interested in natural selection that can be demonstrated in as short a time period as a year.