Darwin's Finches
The finches of the Galapagos Islands have played an important role in helping to understand evolution. While on his 5-year voyage around the world, Charles Darwin saw many different types of finches, based on the size and shape of their beaks. The name "Darwin's Finches" was coined in 1936 by an ornithologist named Percy Lowe, but did not become popular until 1947 when another ornithologist named David Lack published an evolutionary study of the finches. To this day, these finches are still revealing much about the evolutionary process.
Geospiza scandens, or the "cactus finch"
Darwin's Finches share many similarities, such as their size, habitats, and colors. Their differences, however, are found in their beaks. It is believed that at one point in time, there was only one species of finch on the Galapagos Islands. But due to a high number of the same finch and a smaller supply of food, these finches were forced to evolve over time to adapt to different types of food. For instance, the cactus finch has a longer, more pointed beak, so that it can exploit the food sources that are less accessible to other finches. Its beak length allows it to reach between the spines of cacti and eat the seeds that it provides.
Another common example of evolution in these finches is the large ground finch. Due to the limited food supply of the Islands, it was forced to find its food in nuts. It had to evolve so that it could break open these nuts, and therefore gained a large, short beak. This is a completely opposite trait in comparison to the warbler finch, whose beak is thin and sharp so that it can spear insects for its food.
This diversity of finches shows an excellent example of speciation, as they had to evolve into many different species in order to survive on the food their environment had to offer. The variation among finches living on the Galapagos Islands is one of the greatest examples of evolution, and helps the world better understand how and why animals evolve the way they do.
This diversity of finches shows an excellent example of speciation, as they had to evolve into many different species in order to survive on the food their environment had to offer. The variation among finches living on the Galapagos Islands is one of the greatest examples of evolution, and helps the world better understand how and why animals evolve the way they do.