You have spent time working with a population of beetles. Males range in size from 2 to 6 cm in body length. You realize that th
e females only mate with males that measure less than 3 cm long. If you measured allele frequencies at a single locus that contributes to overall body length, would you expect this population to be in Hardy-Weinberg equilibrium for the body length gene from one generation to the next? Select one:
a. Yes
b. No
For a population to be in Hardy-Weinberg equilibrium, it is necessary that the crossings be made completely at random, in the most random way possible. This is not what is happening in the population shown in the question above. This is because if, females only mate with males that are 3 cm long, it means that the crossings are not random, this is occurring preferentially in a specific group of males.
First, let's watch what it looks like when a population is not evolving. If a population is in a state called Hardy-Weinberg equilibrium, the frequencies of alleles, or gene versions, and genotypes, or sets of alleles, in that population will stay the same over generations (and will also satisfy the Hardy-Weinberg equation). Formally, evolution is a change in allele frequencies in a population over a very long period of time, so a population in Hardy-Weinberg equilibrium is not evolving.
