Which of the following is a condition that must be met for a population or an allele to be in Hardy-Weinberg equilibrium?

A The population in question must be small

B Organisms must be free to migrate into or out of the population

C New mutations must be introduced to the gene pool at a consistent and unfluctuating rate

D Organisms in the population must express no mating preferences

The answer is D) Organisms in the population must express no mating preferences.

Some of the conditions that must be met for a population or an allele to be in Hardy-Weinberg equilibrium are:

1. The population must be very large - so A) could not be the right answer.

2. There must be no migration and population must be isolated - so B) could not be the right answer.

3. There must be no mutations - so C) could not be the right answer.

4. There must be random mating, which means there are no mating preferences - so, D) is the right answer.