Question

The genetic basis for variation within a species was not understood at the time Darwin proposed his theory of evolution by natural selection. Based on what you have learned about Mendel’s laws of inheritance and population genetics, explain which factors are key for natural selection to have driven the difference in beak shape of the finches in the Galápagos Islands.

Answer 1

Following could have been the factors for natural selection to driven the difference in beak shape of the finches in the Galápagos Islands:

• Difference in local ecological conditions, like drought.
• Difference in type of food available: from hard nuts to soft ones.
• Song sung by the birds .

All these factors play role in modification of beak shape and size. In drought conditions longer, harder beaks would be favored to obtain nutrition from hard nuts/fruits in dry conditions.

Songs sung in different ways by different species, affects beak shape over a period of time.