The Large Ground Finch lives in the arid lowlands on most of the Galápagos Islands. It uses powerful jaw muscles for its extremely deep and broad bill to crack the very hardest nuts and seeds, giving the bird a survival advantage in the drought season. Charles Darwin was able to correlate the shape of the beaks of Galápagos finches with various diets (seeds, insects, flowers and even blood). Modifications to genes that govern beak development change the size and curvature of beaks and explain diversity among the thirteen different finch species of the Galápagos.
Arkhat Abzhanov, PhD, Dept. of Life Sciences, Imperial College London, UK.