Charles Darwin's Finches Evolved Their Beaks with the Help of This Gene

Scientists have gotten a closer look at the gene that helped spark the theory of evolution. They've identified a gene in Galapagos finches that was studied by Charles Darwin that influences beak shape, and reveals a bit more about the genetic foundation of evolution.

"We now know more about the genetic basis for our evolutionary studies, and this is a highly satisfactory, very exciting discovery after all these years," said Peter Grant, one of the researchers, in a news release.

In order to better understand these finches, the researchers looked at DNA samples collected from the birds. They were able to identify the gene that influences beak shape by comparing the genomes of 120 birds that were all members of the 15 species known as "Darwin's finches." In the end, they spotted a stretch of DNA that looked different in species with blunt beaks, such as the large ground finch, versus species with pointed beaks, such as the large cactus finch.

Within this stretch of DNA, the scientists found a gene known as ALX1, which had been previously identified in humans and mice as being associated with the formation of facial features; in other words, they found the gene responsible. More interesting, though, was that the gene varied among individuals of the same species. For example, the medium ground finch species includes some birds with blunt beaks and some with pointed ones.

"This is an interesting example where mild mutations in a gene that is critical for normal developments leads to phenotypic [observable] evolution," said Leif Andersson, the lead researcher of the study.

The findings reveal how evolution can happen within these species. Some individuals have a trait that aids their survival, such as a blunt beak. Over time, this trait is passed on to their offspring while birds with pointed beaks that are less able to survive end up dying out.

The findings are published in the journal Nature.

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).