Are Humans Still Evolving?
Are humans still evolving? Have you thought about this question? To me, this is a fascinating subject to ponder over. We know that we have evolved into what we are now and so it would seem logical to assume that we would continue to evolve, but can we assume that? I think not. We've heard of the 'survival of the fittest' theory and though it does not exactly describe natural selection, if you go by the logic of it, then this theory is no longer relevant to humans, as it might have been in generations gone by. The reason being that courtesy the medical advances of our times, the weakest, who wouldn't have otherwise survived, continue to survive and pass on their genes to the next generation.
In today's world, almost everyone survives in the developed world (not that they shouldn't), but this basically should negate the 'survival of the fittest' theory.' Medical advances have also offered people the ability to mask their outward appearance through cosmetic surgery and hence what is advertised is not really what exists within their genes. Can this be called cheating evolution? It certainly isn’t natural for sure. There is also the fact that genetic mutations that may offer some benefit may not be passed down generations due to crossbreeding, since we don't live in isolated populations anymore, but travel widely and mix with other populations more often than in the past.
It would seem then that humans have stopped evolving and would continue to remain the way they are in the future. However, this view can't be assumed as well. There is in fact another view that states that evolution in humans is accelerating, with selection of mates being one of the primary sources driving this evolution. So, would humans get more attractive in the future? Maybe, since with medical and genetic advances, people may choose traits for their babies and propagate a particular set of genes. Although this is artificial selection, natural selection may continue to play a role accounting for these man-made changes. We can only speculate as of now.
What happens if humans seek to colonize other planets though? Would humans not continue to evolve then? Well, one would think they would evolve, and evolve differently than us. Such humans would be isolated from the rest of us, on an alien planet, with a different environment, different gravity, etc., so it is possible that they would evolve to look different than us, living on that alien planet years into the future. In such a scenario, those future humans, in that alien world, would probably end up looking quite different than us.
Back on Earth, it is quite possible that, in the future, we may become immortals by uploading our memories (essentially us) online. We may use mechanical bodies to host our scanned/uploaded minds and thus escape the evolution we now know. In this case, humans would have taken control of their own evolution in some ways, and thus would have brought about unnatural selection as opposed to natural selection. Reproduction/replication would continue in this realm as well, the only difference being it will be much faster, than the generational phases we go through now. This may seem fantastical now, but it isn't really beyond the realm of being a possibility in the future. These humans would be immortal in essence, living forever, transcending their biological limitations and would redefine evolution the way we know it.
We may evolve, may stay the same, or not evolve at all. However, it would be most interesting to know how humans would look like a few millions years from now, assuming we survive as a species till then.