Answer
The major evolutionary lesson illustrated by Darwin's finches on the Galapagos Islands is Natural Selection. The finches, although of the same species, lived on different Galapagos Islands. As such, each had developed unique characteristics to survive in their habitat. For example, one island's finches ate bugs, so had a long, needle like beak. Another island's finches ate seeds, so had short, hard, and thick beaks.
Work Step by Step
Finches on different islands had different characteristics.