Not to be a party pooper, but this whole debate is irrelevant. Assuming our civilization goes on for another few hundred years, natural selection wont be a factor any more in human evolution. We're going to control our own evolution. Regardless of what the religious fundamentalists and other conservatives say, we're shortly going to begin tinkering with our gentic code to make ourselves 'better'. Also as humanity starts leaving Earth and living in space and on Mars, the Moon, and elsewhere, our bodies will inevitably begin to change. When humans begin living permantly in space (zero g environments), we'll mimic what happened to other mammals who returned to the oceans. Bone structure will change drastically, our circulatory and digestive systems, our brains, everything. These changes would happen anyway, but theres no doubt we'll help the changes along with genetic engineering. Who needs big powerful tree trunk legs in a zero g environment? Our legs will become shorter and thinner, but probably long, thin arms would be desirable. Two thousand years from now, we'll have several distinct human subspecies, just like existed in our distant past. Space based humans will be one group, and humans who settle other worlds and moons will adapt themselves to their environments. Meanwhile on Earth, there'll be 'designer' humans. Like clothing designers today who set new fashions, genetic designers will recreate humanity in a myriad of forms. If you got into a time machine and went ahead two thousand years, you would be greeted with the same fascination a time traveling Homo Erectus would be greeted today.
Either that, or Ive been reading too much science fiction.
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They're getting your genetic code, no? So what are you worried about? 
