Charles Darwin was most famous for his research on Galapagos finches which ultimately led to the theory of evolution we all know and love today. According to a report from the Washington Post, a recent study published in the journal Science confirms that the birds across the remote island chain are still in a state of evolution.

Scientists from Princeton University reported that they had identified a gene, called HMGA2, that regulates the development of the birds’ trademark beaks. Darwin initially used the wide range of beak shapes and sizes on the finches across the Galapagos Islands to illustrate the properties of natural selection.

HMGA2 was shown to be the main factor in determining beak size. The gene sets off a number of other processes that shape a bird’s beak, and is also present in other organisms like dogs, horses and humans.

Scientists found that the DNA in samples taken from medium ground finches was an accurate predictor of whether or not they would be suited to survive in harsh conditions. Birds with a version of the HMGA2 gene that led to large beaks were much more likely to have died during a severe drought than birds who had a variation that led to a small beak.

Scientists still aren’t positive exactly how the gene influences a finch’s beak size or other growth patterns in different animals, but they believe that it is one of the key indicators of how this crucial component develops.

Finches rely on their beaks to capture food and find water. During a drought when resources are scarce, the birds with smaller and more dexterous beaks have a significant advantage in capturing grubs and small supplies of water over their large-beaked counterparts.

The study builds on previous research on the curious Galapagos finches, and all but confirms Darwin’s initial theory of natural selection. Evolution is an ongoing process, and the recent research shines new light on its underlying mechanisms.

A press release from Princeton University describing the details of the study can be found here.