Have humans evolved? And are we still evolving? To some extent both questions are speculative, but I'm going to assume that we have just based on human biodiversity already in evidence and based on the fact that for example children now are on average significantly larger than their parents just as they were larger than their grandparents.
It seems this trend to get bigger is the most obvious. But is it evolution in the real sense? Evolution as envisioned by Darwin was "survival of the fittest" which meant that the weakest part of the population would die and those with stronger characteristics survived.
But short people don't die more often than tall people in our society and they procreate just as often. It would rather seem that an evolution in human nutrition has led to the whole population changing rather than change being driven by survival.
And I guess to a large extent this is how humanity will have to continue evolving. In modern society people, even those with severe afflictions, usually survive past childbearing age. Intelligence, looks, physical strength, speed, none of these seem to matter at present. Being more successful in modern society does not mean you're more likely than anyone else to pass on genetic material.
However there are still places in the world where survival of the fittest seems to matter. Foremost in this respect would be Africa where unfortunately many people still die far too young. Hopefully this will at least result in those surviving being more likely to withstand disease in future. But this type of evolution seems rather harsh.
A hoped for and desirable effect of evolution would be if it prepared mankind for the future. With technology evolving and the future becoming ever more complex higher intelligence becomes a necessity.
But unfortunately higher intelligence seems to have one unpleasant by-product. More intelligent people seem not mainly focused on procreation but more on their careers. Many even make the intellectual choice not to have children.
Other groups in society however do procreate. Some do so intentionally such as those who believe there is a religious imperative to have many children. Others lack the proper eduction and environment to protect themselves from unwanted pregnancies. As a result the average IQ of the population based on genetics seems to be dropping.
Luckily it seems that besides the genetic factor there are also environmental factors that contribute to levels of IQ. These are for example better education, more exposure to technology and the increased availability of information as well as better nutrition and health-care.
In the end I hope that these environmental factors which are now raising our IQ and increasing our height will continue to outstrip the effect of "survival of the fittest" style evolution where those more willing to procreate dilute the gene-pool to the detriment of the more intelligent.
So what will the human of the future be like? Well I don't think he will be much taller, we are already coming to the limits of what our circulatory system let alone our knees can endure. Six feet might very well become the average height. We will most likely eventually all loose our body hair. The hair on our head might survive as it is both considered attractive and serves a purpose in fending of cold or the sun. And I think we will become a lot more intelligent. We will have to if our species is going to survive.
Hopefully with intelligence we will start to make better choices. It seems likely that with an increasing world population a lot of habits now common will have to go. In order to be able to grow enough crops, crops which are recreational such as tobacco will probably have to disappear and breeding livestock will probably also prove unsustainable. This means a vegetarian future which itself will probably effect the way humans look in future.
So eventually I expect future humans to be a lot thinner and lighter. Fingers might be longer and more flexible to better manipulate all the gadgets we own. We might become more frail as we increasingly find new ways to make technology work for us. If we indeed become vegetarian we might lose some of our teeth as tearing meat is then no longer necessary.
In the end there is no telling how humanity will evolve or even if we will. There is no way to know if we will become one race of coffee colored people living in harmony. There is reason to hope and reason to doubt.
I have stacked my hopes on the evolution of education, nutrition and health care.
My doubts lie with those who seek strength in numbers.
We'll see who is the fittest yet.