"Beak shape" refers to the physical form or structure of a bird's beak or bill. It describes the size, length, width, and curvature of a bird's beak. Full definition
Adaptationism certainly appears to hold true in microevolution — small - scale evolutionary change within species, such as changes in beak shape in Galapagos finches in response to available food sources. (newscientist.com)
There were also strong similarities with genes identified with beak shape in Darwin's study of finches — one of the best - known examples of how physical traits have adapted to different environments in the wild. (sciencedaily.com)
Two species of finch in the Galápagos Islands diverged in beak shape as they adapted to different food sources. (sciencedaily.com)