Mary M.

A keystone species is one that when removed, results in a drastic change to other species, most often seen in their population densities. Using this definition, I think that humans are most definitely a keystone species. We kill such and abundance of wildlife and destroy a large number of species through deforestation and our daily lives in general. If we were removed, populations of all other species would increase, however, I do not believe it would cause chaos. I can not think of any population that would take over, however, we can only speculate since there is no way of knowing our impact on the planet. So we are a keystone species because we would affect the balance of the planet (some species that are endangered would come back and repopulate the world). However, it is arrogant and incorrect to assume that we are the main keystone species. I think grass would come before us in the level of importance because almost every other species feeds off of it. Many species would be destroyed if their main food source (grass) was depleted.