Natural selection is the mechanism of evolution also known as “survival of the fittest”. It can be defined as the natural process in which over time the most favorable traits are passed on and the weaker traits are removed.
The Grants discovered that initially different species of finches had no preference in food, everyone ate the same small, soft seed. Years later after the major drought of 1977 the Grants discovered that many of the birds died which was most likely related to their inability to open seeds and find food. A few years later they discovered the population had began picking up again, but the average bird beak size was larger. They suspect this happened because the birds with larger beaks were able to find food therefore had a better chance of surviving the drought. During droughts large, hard, woody seeds were more readily available and larger beaks were better suited to open/consume the seeds.
Aposematism is an antipredator color mechanism used by potential prey to warn off potential predators with the use bright coloring/patterns to show that they are potentially dangerous. Eastern coral snakes are venomous snakes who also use a bright color pattern to warn off predators. Predators recognize the pattern and avoid the coral snakes. Other snakes such as the kingsnakes also mimic the bright warning pattern of the coral snake to warn off predators. The prey that can use these defense mechanisms survive longer and able to pass on these traits.
