Mammoths are thus not particularly 'alien' organisms from a modern ecological standpoint. They lived and evolved alongside much of the modern flora and fauna, including humans - who are, incidentally, likely responsible for their extinction. It is therefore highly unlikely that the introduction of a mammoth population would severely perturb natural ecosystems. In any case, the extent to which there really is a "benevolent balance of nature" has been vigorously contested in biology. Food webs are often maintained despite significant fluctuations in extinction, invasion, migration, diversity, and energy pathways.