Considering that evolution is such a long, ongoing process there really is no way to predict the course that humanity will follow. Based on approximately six thousand years of recorded history there really has been no significant change in human beings except for longevity which can be attributed to social and technological advances. It is possible to speculate about the next phase of human evolution but, undoubtedly, there will numerous theories as to how it will occur and no way to confirm any of those ideas in the short term.
Until recently evolution has been dependent on the environmental conditions that exist on the Earth but what ever form future human evolution will take will be directly linked to the social and technological advances that humanity achieves. For example, until about a hundred and fifty years ago most human beings did not understand that many diseases were caused by unseen, microscopic germs and that to keep such diseases at bay they simply needed to clean themselves better. Once people realized that the cleaner they were the healthier they were they started living longer. The development of medicines to ward off ailments also contributed to the longevity of human beings by curing once incurable diseases. These social and technological advances are examples of minor evolutionary change in human beings.
Future human evolution will also depend on social and technological advancement but the direction it will take is entirely speculative. It is probably safe to assume that the minor genetic differences in people of African, European, and Asian descent will vanish over the next several thousand years as people become more accepting of each other and disregard those genetic differences. It is probably also safe to speculate that further advances in medical science will lead to increased longevity and quality of life for human beings.
Other technological disciplines that may have an impact on future human evolution include computer science, genetic engineering, robotics, and nanotechnology. Judging how these technologies will influence human evolution is extremely speculative, bordering on science fiction, but if these disciplines are pursued they will definitely have some effect on the human condition. An example of this could be altering human DNA in a way that eliminates the possibility of deformities or congenital conditions that babies could inherit before birth. Another possibility could be people receiving medical treatment from molecule sized nanobots that may be passed onto babies at the time of conception and continue to function as the child grows to maturity. Admittedly, these are extreme possibilities for human evolution but, nonetheless, should be considered.
As stated earlier, it is nearly impossible to predict the next phase of human evolution because of the time tables involved concerning any type of evolution. It is safe to speculate that because human beings possess intelligence then technological and social advances will have as great an impact on human evolution in the future as environmental concerns did in years past.
