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Researchers are pinpointing the genes that lie behind the varied beaks of Darwin’s finches – the iconic birds whose facial variations have become a classic example of Charles Darwin’s theory of natural selection.
Recently, researchers identified a gene that helps to determine the shape of the birds’ beaks. Now in Science, they report a different gene that controls beak size. Shifts in this gene underlay an evolutionary change that researchers watched in 2004–05, during a drought that ravaged the Galapagos Islands, where the finches live. The beak sizes of one population of finches shrank, so as to avoid competing for food sources with a different kind of finch – and their genetics changed accordingly.
“A big question was, ‘Is it possible to identify genes underlying such evolution in action, even in a natural population?’,” says Leif Andersson, a geneticist at Uppsala University in Sweden and one of the study’s authors. “We were able to nail down genes that have directly played a role in this evolutionary change.”
To examine the genetic basis for this variation, the researchers compared the genomes of 60 birds representing six species of Darwin’s finches, along with 120 specimens from other species to help them tease out phylogenetic relationships. As expected, closely related species had the most similar genomes.
Read full, original post: Evolution of Darwin’s finches tracked at genetic level