There are several reasons why the yellow-bellied marmot has developed the social system that it has. For starters, the burrows they inhabit is a direct result of their environment. The burrows keep them warm during hibernaculum in the winter, as well as provide protection from predators. Clearly, the mating/nesting territory provided by the burrow is worth defending because it is such a necessary resource. The marmot has a home range that extends from the burrow because it is necessary for feeding purposes. The rocky outcrops in which they make their burrows does not supply enough food resources for the colony.

The polygynous harem evolved because it is the most fitting mating system there is. It allows for the greatest reproductive success for both males and females. The males benefit by being able to mate with more than one female, and females benefit by having the younger females aid in raising the litter, thus increasing their reproductive success.