STATES CHRONICLE – Few particular animal families are as popular in the world of science as Darwin’s finches. Primarily thanks to the role they played in Darwin’s theory of evolution, the finches on Galapagos Island have become pretty much celebrities in their own rights. Luckily for them, they escaped the fate of extinction that befell their turtle neighbors after Darwin himself ate forty of the rare creatures on his way back from the island.
Still, they did almost go extinct last year, as a very invasive species of parasitic fly took over the island, killing the finches’ newly hatched babies by the scores. Scientists intervened, however, and are still getting rid of the very troublesome pest.
So, with all the attention surrounding them, it’s no wonder that the birds are still being investigated and looked into by scientists all over the world. And now, finally, 157 years after the man’s Theory of Evolution was initially published, scientists discover gene responsible for Darwin’s finches’ evolution.
The evolution involved in the finches’ case is quite simple: species competing for the same resources, including food, tend to differentiate themselves from one another in order to decrease the competition. As the creatures eat pretty much the same thing, seeds, they had to differentiate so that different species eat different seeds if they wanted to survive.
Around for some two million years, the birds separated over time into eighteen different species of various sizes, songs, eating habits, and beak shapes. But scientists managed to observe such a change over the course of just a few short years, as the birds were put in a hitch by the lack of food on the island.
And luckily for them, scientists were around to study the birds. A team of researchers composed of scientists from both the Princeton University and the Uppsala University identified the gene HMGA2 as the one behind the birds’ beak shape and that drives changes to the creatures’ anatomy.
As a severe drought hit the island in 2004 and 2005, the competition for food intensified to very high levels. The scientists noticed that during the drought, the medium ground finches’ beaks started getting smaller, so they could smaller seeds. This happened because they just couldn’t compete with the larger species for food.
The speed with which the changes happened in the birds biology came at a pace previously thought impossible, albeit it happened at the cost of a huge number of deaths among the larger beaked birds. This led the team to target the HMGA2 gene and focus on it, as it is one of the most quickly adapting genes of the sort that they or anyone has ever found.
Image source: Wikimedia