Finch evolution
Princeton researchers Peter and Mary Grant have been studying the evolution of Darwin’s finches for over 40 years, with a concentration on the island of Daphne Major. The 13 finch species found in the Galapagos are spread across the islands, and have all adapted to fill various ecological niches created by differences in island size, height, and topography. DNA analysis of the finches has shown that they are more closely related to each other than they are to any mainland species, which means that they must have all diversified from one single ancestral species that colonized the Galapagos.
Although not always seen, the finches continue to evolve. On Daphne Major, changes in food supply (due to lack or overabundance of rainfall) have led to the evolution of the ground finch population. When smaller seeds are more readily available, the birds with smaller beaks have a higher chance of survival, and the next generation’s beaks are smaller. When larger seeds are dominant, the finches with larger beaks have a higher chance of survival, and the next generation will have larger beaks. As the first finches in the Galapagos began to colonize different islands, the varying conditions they encountered led to changes more extreme than those observed on Daphne Major. Eventually, these changes led to the inability of the finches to breed with other populations, and they became a new species.
It’s really incredible that evolution can be observed in such a short time period on Daphne Major. The Galapagos’ unique environment makes it a perfect location for studies like the Grants’; this is one of the many reasons why it’s critical to protect the islands.
Although not always seen, the finches continue to evolve. On Daphne Major, changes in food supply (due to lack or overabundance of rainfall) have led to the evolution of the ground finch population. When smaller seeds are more readily available, the birds with smaller beaks have a higher chance of survival, and the next generation’s beaks are smaller. When larger seeds are dominant, the finches with larger beaks have a higher chance of survival, and the next generation will have larger beaks. As the first finches in the Galapagos began to colonize different islands, the varying conditions they encountered led to changes more extreme than those observed on Daphne Major. Eventually, these changes led to the inability of the finches to breed with other populations, and they became a new species.
It’s really incredible that evolution can be observed in such a short time period on Daphne Major. The Galapagos’ unique environment makes it a perfect location for studies like the Grants’; this is one of the many reasons why it’s critical to protect the islands.