AP BIOLOGY

Detailed explanation-1: -Natural selection occurs only if there is both (1) variation in the genetic information between organisms in a population and (2) variation in the expression of that genetic information-that is, trait variation-that leads to differences in performance among individuals.

Detailed explanation-2: -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-3: -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-4: -Overproduction of offspring’s leads to competition among individuals in which the fittest and adapted individual survives. Overproduction is also known as a driving force in natural selection as it can lead to adaptation and variation in a species.