A Galapagos finch that helped reveal the origins of species to Charles Darwin has now undergone a spurt of rapid climate-driven evolution, biologists report.
The medium ground finch (Geospiza fortis), of Daphne Island was nudged, and then shoved, to evolve a smaller beak.
This happened by the combination of competition from another finch that arrived on the island more than 20 years ago and more recent drought conditions.
“It happened very fast,” says biologist Professor Peter Grant of Princeton University.
He and Dr Rosemary Grant publish their discovery in the latest issue of the journal Science.
In fact, it happened in a single bird generation, Grant explains.