Natural selection.
Darwin formed his hypothesis
of natural selection by drawing two inferences based on his observations.
- Observation #1
: Individuals of a population
exhibit variation in their traits.
- Observation #2
: Many traits
are heritable.
- Observation #3
: Many species overproduce offspring.
- Observation #4
: Resources are limited;
many of these offspring do not survive due to competition for those resources.
- Inference #1
(natural selection): Individuals whose traits give them a high probability of
surviving and reproducing
are likely to leave more offspring than others.
- Inference #2
(adaptation): A population will accumulate favorable traits
over generations and become adapted to its environment.
