Final answer:
The Selection Differential is the difference between the mean trait value of the entire population and that of the individuals who successfully breed, reflecting the strength of natural selection on a specific trait.
Step-by-step explanation:
The difference between the mean value of a trait in the entire population and the mean value of the individuals that breed successfully is known as the Selection Differential. This term describes a measure of the strength of natural selection in a specific trait. The Selection Differential is calculated by subtracting the mean trait value of the breeding individuals from the mean trait value of the entire population. The outcomes of this differential represent a directional change in traits within a population owing to selection pressures.
It's important to note that the Selection Differential is only one component of evolutionary change. To fully understand how a population evolves over time, scientists consider factors such as genetic drift, gene flow, and of course, the genetic variance within the population which drives the response to selection.