As any avid biologists know, Darwin's theory of natural selection is entirely based on two hypotheses: 1. Members of species have individual and diverse traits which have the capability to be passed onto their offspring. Basically, these means that all individuals have the ability to pass their unique, and occasionally beneficial, mutations unto their children. 2. Fight for survival. Basically, this means that in the harsh world of nature, every member of a species has to fight to survive with the set of inheritable traits they are given. Individuals with beneficial mutations most often survive longer and produce larger amounts of offspring, and thus these sub-species eventually become a dominant force in an ecosystem. But here we are in the 21st century, and humans have reached a level of evolution previously unknown on planet Earth. We have no natural predators, and thus no one need fight for survival. Also, the diversification of the human race ultimately means that those who mutate in accordance with their environment will more than likely never encounter others with similar mutations. Thus, we will be stuck as homo sapien sapiens until we eventually destroy ourselves some way or another.