How finch beak shape can show us real-time natural selection. Darwin’s finches are said to be one of the animals that helped Darwin to form his Theory of Evolution, and they continue to be an important study species for those interested in evolution and natural selection.
What makes Darwin’s finches distinct, and easy to study, is the different beak shapes that they have, which help define what kind of food they eat. In ecology, finches follow a principle called “niche partitioning” – where different animals eat different kinds of foods so that they do not have to compete with one another as much. For example, finches with thin beaks eat small seeds, whereas larger beaked finches are designed to crack open tougher seeds and nut-like fruits. If there were many large beaked finches on an island and a lot of competition, there would be natural selection for more birds with thin beaks, as the thin beaked birds could successfully have babies and then more and more thin beaked birds would show up over time, until it balanced out.
Additionally, more studies have shown that when a disaster strikes the population of birds with certain beak sizes will change. For example, a dry and hot climate event that wiped out many plants with large seeds on one island resulted in the bird population shifting to mainly thinned beaked individuals, in only a few short years. This event was a prime example of natural selection and evolution that could be observed in a very short time period.
The Galapagos Islands are often referred to as a “living laboratory” for this very reason, and many interesting natural and scientific facts and discoveries await you on your next journey with us!