In a recent article
, Denis Reale, posed the question of continued human evolution to a number of high school students, who in keeping with much of modern society believed that human evolution has drawn to a standstill. Culturally and socially we have been lead to believe that humanity, having reached the pinnacle of evolution, has simply ceased to evolve and that our children and great grandchildren will have exactly the same characteristics as we do.
In fact according to many studies nothing could be further from the truth. If anything humans are evolving at a much faster rate, and changes that once took several ages to manifest are now being seen within a much shorter span that can be as short as a few generations. This concept, known as rapid evolutionary change or contemporary evolution, is certainly not radical and while humans are not about to grow gills or wings any time soon, the changes are definitely apparent.
In 2002, much was made of a story by many international media outlets that the blond gene was in regression and eventually all the blonds of the world would disappear. Based on a supposed study by the World Health Organizations (WHO), and citing evidence by German researchers the story went viral. Alarmist in nature the proclamation was that within 200 years there would be no more blond humans on the earth and one outlet
went so far as to predict that the final blond woman, on earth, would be born in Finland. Needless to say WHO never conducted such a study, and the story was thoroughly debunked with the Times of India’s Chidanand Rajghatta calling it a “pigment of the imagination
”. Meanwhile, evolution in humans continues. With most changes apparent in the DNA and genetic compositions of a population. Not radical, but subtle and ongoing.
Dr. Rebecca Rogers Ackermann
, Associate Professor of The Department of Archeology at the University of Cape Town, suggests that evolution simply has not stopped and will continue for some time into the future. In her article “Human Evolution: The Evidence All around Us
”, she writes
Some of the best evidence we have for current evolution is tied to disease susceptibility and/or resistance (such as the balancing selection that is maintaining sickle-cell anemia in some African regions because it offers protection against malaria), and there is a lot of current research on identifying the selective pressures shaping modern humans
Dr. Stephen C. Stearns
, Professor of Ecology and Evolutionary Biology at Yale University, in a 2009 article in Time
Magazine discussed his work regarding natural selection and fertility among humans today. The team studied women participating in the Framingham Heart Study and found that if trends were to continue, with no changes in the culture that might influence child bearing, over the next ten years the average Framingham woman would be shorter, slightly heavier, give birth to children earlier, and enter menopause later. To sum up the findings Dr. Stearns had this to say
That rate of evolution is slow but pretty similar to what we see in other plants and animals. Humans don't seem to be any exception
Evolution has always been driven by a need to survive, hence the term natural selection. Today’s evolution is no different and we are starting to see a very distinct battle emerging in some parts of the world with regard to the human body’s determination to survive the onslaught of life taking diseases.
Dr. Sarah Tishkoff
, a Geneticist at the University of Maryland
In Africa, people are dying daily [of infectious disease], and those who have genotypes that confer some resistance are going to have more offspring. That is natural selection in action.
Through work in Africa, geneticists are finding that there are certain groups of people who have more resistance genetically to Malaria
. These groups that are found only in sub-Saharan Africa and fresh evidence shows that their genes have been under recent pressure in the selective process.
Other research has found that there are genetic mutations, changes in specific genes (CCR5),that provide very clear resistance to the HIV virus. This mutation, commonly known as delta 32, is found in 13% of European populations but is virtually absent in African and other groups. Researchers believe, that uninfluenced by advances in medical science, the AIDS epidemic will continue to make natural selection and eventually much larger swathes of the human population will have the delta 32
It is important to note that evolution is not designed for anything more than to increase the likelihood of reproduction
, increase the reproduction of certain elements and reduce the reproductive rates of “weaker” parts of the species. These happenings can, in modern society, also be triggered by cultural climate and social norms. For example, we find that there is a shift towards younger childbearing because of genetic influences, at the same time one cannot discount the enormous pressure of social acceptance should society move in one direction on this issue.
The answer to the question is quite simple. We are evolving and will continue to do so, in a steady pattern and stable manner befitting the process and in keeping with the long and storied history of natural selection.
Ackermann, D. R. (2006). Human Evolution: The Evidence All Around US. Science In Africa.
Balter, M. (2005, July 8). Are Humans Still Evolving. Science, 234-237.
British Broadcasting Company. (2002). Blondes to die out in 200 years. BBC.
Grabianowski, E. (2008). How Natural Selection Works. How Stuff Works.
Harrell, E. (2009, October 23). Darwin Lives ! Modern Humans are still Evolving. Time.
Rajghatta, C. (2002, October 3). Blondes Extinction is a Pigment of Imagination. The Times of India.
Science Daily. (2005). Biologists Discover Why 10 Percent Of Europeans Are Safe From HIV Infection. Science Daily.