Negative Frequency Dependent Selection

The fitness of a trait expressed an individual in a population is determined by a few factors. In broad sense heritablilty, the proportion is measured by genetic variation to genetic variation and environmental variation. The greater the environmental factors, the less likely that the trait is influenced by genetics and less likely that the trait can be passed down. In terms of narrow sense heritability, other genetic factors are measured to determine if internal/external environmental conditions contribute. If a trait has high fitness, relatively high survivial rate and produce a large number of offspring, then traits with high heritability will likely be passed to offspring. This will result in a selection differential between the mean of the general population and the population of breeders, creating a directional slection pattern if the traits are graphed. The reaction to selection may also be quantified by multiply the heritability of a trait with the selection differential. Fitness does not necessesarily correlate with high frequency. Sometimes traits with low frequency express a higher fitness which is known as negative frequency dependent selection.