What are some advantages of the life cycle of an impala and salmon

Female salmons lay up to 1000 eggs and if some of them die the others left can easily reproduce more and for impalas, when pregnant they can wait up to an extra month to give birth and this can really help if the weather isn’t good or so things wrong they can wait a bit longer.

the darker peppered moth species were favored due to the fact that the industrial revolution had made all the nearby trees a darker color instead of white.