This video says about itself:
Associated Press reports:
Finches Named for Charles Darwin on Galapagos Islands Evolve Smaller Beak, Confirming His Theory
By RANDOLPH E. SCHMID,- AP Science Writer
WASHINGTON Jul 13, 2006. Finches on the Galapagos Islands that inspired Charles Darwin to develop the concept of evolution are now helping confirm it by evolving.
A medium sized species of Darwin’s finch has evolved a smaller beak to take advantage of different seeds just two decades after the arrival of a larger rival for its original food source.
The altered beak size shows that species competing for food can undergo evolutionary change, said Peter Grant of Princeton University, lead author of the report appearing in Friday’s issue of the journal Science.
Grant has been studying Darwin’s finches for decades and previously recorded changes responding to a drought that altered what foods were available.
It’s rare for scientists to be able to document changes in the appearance of an animal in response to competition.
More often it is seen when something moves into a new habitat or the climate changes and it has to find new food or resources, explained Robert C. Fleischer, a geneticist at the Smithsonian’s National Museum of Natural History and National Zoo.
This was certainly a documented case of microevolution, added Fleischer, who was not part of Grant’s research.
G. magnirostris was able to break open and eat these seeds three times faster than G. fortis, depleting the supply of these seeds.
In 2003 and 2004 little rain fell, further reducing the food supply.
The result was high mortality among G. fortis with larger beaks, leaving a breeding population of small-beaked G. fortis that could eat the seeds from smaller plants and didn’t have to compete with the larger G. magnirostris for large seeds.
See also here.
Plant species around Darwin’s house in England, then and now: here.
- Galapagos Warbler Finch (animalbytescambridge.wordpress.com)
- Southeast Asian Commonalities (openthedorr.wordpress.com)
- Video Of The Day: Galápagos Islands Captured On A Cellphone (gadling.com)
- Darwin letters reveal emotional side (bbc.co.uk)
- Darwin (bioventures.wordpress.com)