key term - Directional Selection

Definition

Directional selection is a type of natural selection where individuals with traits that are either higher or lower than the average value for the population have a better chance of survival and reproduction. This leads to a shift in the average value of the trait over time.

Related terms

Stabilizing Selection: Stabilizing selection is a type of natural selection where individuals with average values for a trait have a higher fitness compared to those with extreme values. This leads to a reduction in variation for that particular trait within the population.

Disruptive Selection:

Disruptive selection is a type of natural selection where individuals with extreme values for a trait have higher fitness compared to those with intermediate values. This can lead to the formation of two distinct phenotypic groups within a population.

Adaptive Radiation:

Adaptive radiation refers to the diversification of species from an ancestral species into multiple ecological niches. It typically occurs when new environmental opportunities arise, allowing different populations to adapt and evolve specialized traits.