But what does natural selection mean for the human race, a race without any natural enemies (except itself, arguably)?
It means what it has meant for eons, as you say. The natural course of human nature will have each woman give birth to a far greater number of children than is necessary for strict replacement of the population. The result is an exhausting of resources.
For example, in many parts of the world there are still large numbers of deer, but man has driven away or killed most of their natural enemies, like wolves. As a result, the deer population explodes, and when winter comes in, there is not enough food to feed all of the deer throughout the winter, and very few survive. So hunting licences are granted in the fall to cull off the excess population (maybe 5-15%) so that the remaining ones have enough food for the winter.
In the case of deer, it is man that spoiled the natural flow, by killing off the predators. In the case of mankind, it is again man itself which has upset the balance of nature. Medical advances now make sure that not only do people live a lit longer, but children that would have been naturally culled out of the population by diseases such as polio, malaria, or smallpox, or plague now survive to reproduce (the weaker links, perhaps, genetically speaking). As a result, the diseases that used to keep the population growth to reasonable rates no longer serve that function. Result, population explosion - particlularly among the poorest classes, which have always had a lot of children in order to have them help out on the farm etc, and who traditionally had access to no health care at all.
In addition, the world no longer has wars like it used to. There used to be a big war every few years that would wipe out large percentages of the population, thus also keeping the population in check. Now that nuclear weapons exist, nations are afraid to allow a war to happen, so for the past 50 years, we have had a few minor conflicts, but no massive ones that take out 20% of a continent.
So it is the ultimate irony that mankind's advances in medicine and the institutionalization of regular diplomatic channels to be used instead of war will eventually result in mankind exceeding the capacity of the plannet to provide for it. Unless something is doe, in the next 100 years or so we will ses mass famins of a sort undrempt up of today. We are talking about billions of deaths from hunger.
Now...who's genes would you rather return to the gene pool? Kelly and Jack's or Einstein's? And what process would you like to use to control evolution? Natural selection or economics?
Did Eistein's parents depend on welfare? No? Then there is hardly a reason to bring him up. Clearly his parents were capable of handling the job.
As far as Kelly and Jack, they are bad examples. They are freaks, which is why they are on TV
and the rest of us are not.
The only thing you should feel when shooting a terrorist: Recoil.