Complete sequencing of the genomes of the famous "Darwinian" finches made it possible to isolate several new species and find a gene that is associated with the shape of the beak. In humans, this gene may be responsible for many of the facial features.
During his famous voyage around the world on the Beagle, Darwin visited the Galapagos Islands, where he was especially interested in the variety of local finches: almost every island has its own highly specialized species of these birds. Subsequently, 15 species were identified, united in the subgenus Geospizinae, which became one of the classic illustrations of the inexorable evolution.
Indeed, the diverse species of finches in the Galapagos Islands and Costa Rica are remarkably adapted to the local conditions that exist locally on each particular island. They are believed to have inspired many of the concepts of Darwinian theory, such as adaptive radiation and artificial selection.
Geneticists recently performed the first complete sequencing of the genomes of these birds; DNA from a total of 120 finches was used in the work. This made it possible to distinguish three previously unidentified species. What's even more interesting is that scientists drew attention to the ALX1 gene, the state of which correlates with the shape of the beak: one variant is associated with a long and thin beak, another with a short, and the third with a blunt beak.
This gene is also present in humans. Doctors know that mutations that disrupt its work lead to the appearance of such a developmental anomaly as frontonasal dysplasia. This is a very unpleasant violation of the shape of the face, which can have a variety of specific manifestations, from the absence of a tip to the appearance of a "proboscis", deformities of the skull and even the brain. It is possible that different functional variants of ALX1 are generally associated with different shapes of the face and nose.