ARE WE STILL EVOLVING?
Are We Still Evolving?
Kenneth Posley
ITT-Technical Institute
Are We Still Evolving?
The answer to the question at hand is some-what debatable among certain communities and also a bit perplexing to the general population. Undoubtedly we are, with the world’s population at 7 billion people we are apparently evolving because we are still reproducing and at an alarming rate. But something incredibly weird has happened to human evolution. Only 0.1% of the human genome exhibits variation, in other words we are 99.9% genetically identical. Compare any two humans, and they are vastly more similar genetically than, say, a Western and Central African Chimpanzee.
Between 8,500 and 2,500 years ago, humans started behaving differently. Many were abandoning their hunter-gatherer way of life for a more sedentary one in which they had fixed homes and farmed the land. This period is known as the Neolithic revolution. Changes in culture during the Neolithic revolution hugely altered the selection pressures which would guide the natural selection of human individuals.
Many genes increased in frequency during the Neolithic revolution, due to major changes in diet.
AMY 1, a gene that currently exist in the human genome at between 2 and 15 copies, depending on the individual. The gene AMY 1 which is code for the enzyme amylase is used for fuel respiration. So people who contain a higher copy number of AMY 1, can break down more starch as apposed to someone with a lower copy number of the gene. Interestingly enough, individuals with a higher copy number AMY1 are well associated with region where starchy food are a key staple in day to day diet. So in Japan, Europe and the USA, starch has historically been essential to the diet, AMY 1 levels are higher, whereas the Mbuti and Biaka people of Africa have comparatively lower AMY 1 copy numbers.
With the progression of today's society, diet isn't the only thing change but...