AP BIOLOGY

Detailed explanation-1: -There are four principles at work in evolution-variation, inheritance, selection and time. These are considered the components of the evolutionary mechanism of natural selection.

Detailed explanation-2: -The essence of Darwin’s theory is that natural selection will occur if three conditions are met. These conditions, highlighted in bold above, are a struggle for existence, variation and inheritance.

Detailed explanation-3: -Natural selection causes populations to become adapted, or increasingly well-suited, to their environments over time. Natural selection depends on the environment and requires existing heritable variation in a group.

Detailed explanation-4: -The motor of natural selection is differential reproduction. Organisms are selected to behave in ways that are reproductively successful. Reproductive success can be direct or indirect. An organism can have offspring, or it can help other related organisms (that share a proportion of their genes) to reproduce.