Evolution of human

The speed of human's evolution is more fast for last forty thousand years according to the recent research. This research team said they studied thecangeof genetic code for last eighty thousand years on the difference of DNA's arrangement and found the change of genetic code was speeding up about forty years ago. This is because the number of people is increasing, they have to live in various areas and have to need to adapt various climate, food, illness, enviornment. But there is another view it cannot be explained simply by these natural selection.