Final answer:
The equation for evolutionary change in the mean of a trait is the Natural Selection equation (Choice C), which is used to infer evolutionary changes when allelic frequencies deviate from the predictions of the Hardy-Weinberg equilibrium.
Step-by-step explanation:
Equation for Evolutionary Change in Mean of a Trait
The equation that most directly relates to the evolutionary change in the mean of a trait is the Natural Selection equation (Choice C). While the Hardy-Weinberg equilibrium gives scientists a baseline expectation for allele and genotype frequencies in a non-evolving population, it is not the equation for evolutionary change itself.
Evolutionary changes can be inferred when observed allelic frequencies differ from those predicted by the Hardy-Weinberg equation, indicating forces such as natural selection, mutation, genetic drift, or migration are at play. As such, deviations from the Hardy-Weinberg equilibrium can signal that evolutionary changes are occurring in a population.
The Hardy-Weinberg principle provides a mathematical baseline for a non-evolving population. If the frequencies of alleles or genotypes deviate from the value expected from the Hardy-Weinberg equation, it indicates that the population is evolving.
However, natural selection is the primary force driving evolutionary change, as it acts on the variation in traits and favors certain traits over others.
The equation for evolutionary change in the mean of a trait is C) Natural selection equation.