Reproduction is linked to the stability of populations of species. Populations of organisms fill well-defined places, or niches, in the ecosystem, using their ability to reproduce.

The consistency of DNA copying during reproduction is important for the maintenance of body design features that allow the organism to use that particular niche. The DNA copying mechanism cannot be absolutely accurate, and the resultant errors are a source of variations in populations.

However, niches can change because of reasons beyond the control of the organisms, such as temperature changes, varying water levels, or meteorite hits. If a population were suited to a particular niche and the niche were drastically altered, the population could be wiped out.

Variation is thus useful for the survival of species over time. If some variations were present in a few individuals, there would be some chance for them to survive. For example, if water temperature increased by global warming, most bacteria would die, but the few variants resistant to heat would survive and grow further.

Thus, reproduction provides stability by maintaining body design features through DNA copying, while also generating variations that allow populations to survive even when environmental conditions change.