Which is not a requirement for natural selection to occur?

The Hardy – Weinberg principle has seven conditions that should occur in the evolution of the population. One is when mutation does not happen. Two, is when natural selection is not occurring. Three, if the population is infinitely large. Four, if all the members of the population produce offspring.  Five, sexual intercourse is random. Six, the population will produce the same number of offspring. And lastly, the population does not migrate from one place into the other. The thing that would disrupt the genetic equilibrium is the mutation.

i think the answer is

mass