The Continuing Evolution of Man
Although the mystery of human evolution is still being studied today, people have begun to question whether man is still evolving currently and, if so, whether he/she will continue evolving indefinitely. Some have thought that human evolution has slowed down and may even come to a stop at some point in the future. Most scientists, however, believe that humans are still evolving and, indeed, are actually evolving faster now than before. Granted none of us could see evolution taking place, but we have been able to surmise with a degree of certainty that man, over the past several hundred-thousand years, has indeed been evolving from more primitive ancestors.
There are several key indicators showing man’s continuing evolution: man’s average life span has continued to increase; man has become much healthier than his ancestors; man’s physical attributes keeps changing and improving; and man’s intellectual abilities has continued to increase, at a more rapid pace over the past two thousand years. Through scientific studies and analyses of human remains obtained from thousands of years ago, we could now see some of the evolutionary changes in man. For example, from the study of human fossil, we learn that the physical characteristics of people who were here about 10,000 years ago resemble more with their remote ancestor, the Neanderthals, than they do present day humans . This finding shows that humans appear to have evolved faster during the past ten thousand years, than say, our ancestors fifty thousand years ago.
Other scientific findings of human evolution support the theory that man continues to evolve, and that he appears to be evolving faster than before. For example, technological advances made by man during the past several thousand years (such as those when man started farming, staying in one place, and raising domesticated animals), appear to have been instrumental in determining the natural selection of and the evolution of humans. A very good example of this is the ability of humans to increase their tolerance of lactose. Prior to the age of dairy herding, humans were unable to digest lactose, a sugar found in milk. In order for humans to be able to begin drinking milk and eating dairy products, a particular gene in man, surprisingly, developed the ability to digest lactose [2, 6]. Thus, contrary to the belief by some that technological advances would somehow slow down human evolution, this example shows how a particular change in man’s life-style, including advances in technology, do in fact spur human evolution. Because technological advances today are being made at such a rapid pace, we could only surmise that man will hereafter evolve at a much faster rate. Thus, when man develops the technology to explore and settle on distant planets (though this possibility seems more science-fiction than real), if it does happen, man will clearly have to adapt himself if he is to survive and live on those planets.
Current scientific discoveries have also provided proof of continuing human evolution. For example, through genetic screening--looking at and comparing the human genome of past and current populations, we could actually see the changes that have taken place in man’s biological and physiological characteristics. By examining more than three million variants of DNA in 269 people, researchers have identified about 1,800 genes that have been widely adopted in recent times because they offer some evolutionary benefit .
Researchers have also found that at least seven percent (7%) of human genes have undergone recent evolutionary changes over the past, several thousand years. These changes include lighter skin and blue eyes in northern Europeans and partial resistance to diseases such as malaria among African populations [3, 4, 5]. With the advances being made in scientific technology, we are also able to see evolution that has taken place at the molecular level. We now know from data collected that the DNA of human populations have actually been changing and will most likely continue to change due to mutations.
Modern scientific studies and findings clearly support the theory of human evolution. The findings of the pre-eminent naturalist, Charles Darwin, provide some of the initial scientific theory for the evolution of the different types of species. Although Darwin does not explicitly say that humans fit into his theory of evolution, the ideas he presents in his treatise On the Origin of Species is in line with the theory that man, as a species, is also still evolving. First, his theory of natural selection strengthens the evidence of lactose tolerance, skin color changes, and disease resistance. Over time, these changes were naturally incorporated into the human specie for man’s benefit.
Second, Darwin says that variation among a species is needed in order for evolution to occur. It is quite clear that there has been a lot of variation among humans today. No two people (with the exception of identical twins) have the same genetic material. Therefore, evolution will almost certainly continue to take place.
Finally, Darwin argues that reproductive success is required in order for evolution to take place. With the development of in vitro fertilization, we now have an alternative source for reproduction, assuming one is infertile. Today, almost any female could conceive a child. Thus, it appears that evolution will continue, through the normal reproductive process or through the help of in vitro technology.
As modern scientists look at the evidence of human evolution, they have also begun to believe that we might actually be evolving at a faster rate than previous ancestral evolution. One study suggests that human evolution has accelerated 100-fold in the past 5,000-10,000 years. This was figured out by comparing chunks of DNA among people around the world. Because human populations today are acquiring mutations at a faster rate, the chances for natural selection have become greater and the chances for evolution to occur is faster [1, 2].
Another reason for the theory that evolution is taking place now at a faster pace is the fact that human lifestyle is changing at a faster pace. As a result, the human genome has apparently been scrambling to adapt to these changes . What is interesting about this view of faster human evolution is that Darwin himself would be surprised that human adaptability to his environment has occurred much faster since his time because he argued that evolution is a gradual process, one that would stay fairly constant.
Scientific analysis of the current state of human evolution has brought up the question of whether humans will evolve for the better or for worse. Darwin would argue that humans will continue to evolve for the betterment of man. His theory of natural selection suggests that particular traits are selected for advantageous reasons, i.e. to adapt oneself more perfectly to his environment and surroundings.
Present day science also believes that evolution will continue to take place to man’s benefit. Because scientific technology now allows for DNA testing and pre-implantation genetic diagnosis, parents may soon be able to choose the genetic makeup of their children. This would allow for the rejection of undesirable or flawed embryos [1, 2]. Therefore, “better” or “more normal” humans would persist.
Aside from the foregoing, I believe that as the different groups of people on earth start to truly become one global community there will be more interracial breeding and this would encourage a “global gene pool.” This may either be beneficial in that it could increase diversity so that there are more traits to select from or detrimental in that mankind would eventually turn into a uniform race of coffee-colored people. This would take place hundreds of years from today, but the chances of man becoming truly one mankind may be real possibility.
Though the study of how man has continued to develop over the past hundreds of thousands of years, we have begun to understand the current state of human evolution. It is still uncertain though what the future of human evolution itself will be. This remains to be seen. If human evolution somehow ceases, it will be because man has destroyed himself in the process.
- Shute, Nancy. “Where is Human Evolution Heading?”. U.S. News. 24 July 2008. <http://www.usnews.com/articles/science/2008/07/24/where-is-human-evolution-heading.html?PageNr=2>
- Douglas, Kate. “Are we still evolving?”. New Scientist. 11 March 2006. <http://www.newscientist.com/article/mg18925421.300-are-we-still-evolving.html>
- Wade, Nicholas. “Still Evolving, Human Genes Tell New Story”. The New York Times. 7 March 2006. <http://www.nytimes.com/2006/03/07/science/07evolve.html>
- Kaplan, Karen. “Study finds humans still evolving and quickly.” Los Angeles Times. 11 December 2007. <http://www.latimes.com/news/nationworld/nation/la-sci-evolution11dec11,1,2206745.story?coll=la-headlines-nation>
- Sample, Ian. “Humans still evolving—and its happening faster than ever.” The Guardian (United Kingdom). 11 December 2007. <http://www.guardian.co.uk/science/2007/dec/11/evolution>
- Keim, Brandon. “Humans Evolving More Rapidly Than Ever, Say Scientists”. Wired Science. 10 December 2007. <http://blog.wired.com/wiredscience/2007/12/humans-evolving.html>