In assessing the future of human evolution, we have already accepted that evolution exists and is an on going process. Evolution plays a central role in the development of all living things. From the primordial soup, life on earth has evolved in a systematic and unstoppable pattern.
In, The Origin of Species, Darwin states that variation in a species is a random occurrence, and an organism's ability to survive is determined by how well it can adapt to its' environment.
Scientists now believe that humanoids evolved at different times and at different places on earth. Some of the first homo sapiens made it to a certain stage of development and then vanished as a result of not being able to adapt to their environment. This may have been happening at the same time in different places on earth. Some of these early humanoids may have succumbed to changes in climate. Predators, be they animals or more evolved humanoids, may also have contributed to the extinction of some of these early humans. By unearthing fossils, we can only speculate on how they fit into the evolutionary puzzle. Today's technology has forced us, in some cases, to back track and reassess our findings.
In assessing the future of human evolution, we can begin with our own bodies. We need look no further than at our appendix and our tailbone. These two vestiges, to some degree, help us to understand how evolution happens. The appendix, a fingerlike protrusion in our intestine, was probably used in the digestion of plants. This organ suggests that man was an herbivore at some point in his development. As we changed our diet and became omnivores, eating more and more meat, the appendix began to atrophy. The tailbone, at the tip of our spine, hair and all, is a throwback to a prehensile tail. At some point in time, our need to swing from limb to limb became less important, hence the loss of our tail.
There are even minute changes in our physiology that we can point to from the near past. Visit a whaling ship and you can easily see that the average height of humans has changed in just a few hundred years. It may very well be that evolution is actually speeding up.
If adaptation caused the aforementioned changes to occur, we might speculate the same thing will happen in the future.
If our brain evolves to the point of being able to communicate without the use of sounds we may very well not need ears, or our vocal cords may atrophy. If the makeup of our air were to change, due to pollution, slowly and over extremely long time, we may very well develop lungs that would process this new mixture.
When the earth is covered by water, as some point to, in the future, we may very well develop gills that allow us to breathe as fish. After all, whales have vestiges of legs.
The ultimate change might come when we travel to other planets that are marginally inhabitable. The first inhabitants may need to use equipment to survive, but as time passes, we may evolve into a species that doesn't resemble us at all. Man may evolve into something other than what we consider human. As long as the universe exists, evolution will continue to bring about changes in all living things. Some will adapt and survive; others will go the way of the dinosaur. Intelligent life is at the top of the evolutionary ladder at the moment. This could be said about the amoeba at some point in the past.
It's hard to predict how man will evolve in the future. The only thing that is certain is: he will adapt and evolve, or he will become extinct.