The researchers put this acceleration down to two things. First, the human population has expanded rapidly during that period, which increases the size of the gene pool in which mutations can occur. Second, the environment in which people find themselves has also changed rapidly, creating new contexts in which those mutations might have beneficial effects.
That environmental change itself has two causes. The past 80,000 years is the period in which humanity has spread out of Africa to the rest of the world, and each new place brings its own challenges. It has also been a period of enormous cultural change, and that, too, creates evolutionary pressures. In acknowledgment of these diverse circumstances, the researchers looked in detail at the DNA of four groups of people from around the planet: Yoruba from Africa, Han Chinese and Japanese from Asia, and Europeans.
Various themes emerged. An important one was protection from disease, suspected to be a consequence of the increased risk of infection that living in settlements brings. In this context, for example, various mutations of a gene called G6PD that are thought to offer protection from malaria sprang up independently in different places.
A second theme is response to changes in diet caused by the domestication of plants and animals. One example of this is variation in LCT, a gene involved in the metabolism of lactose, a sugar found in milk. All human babies can metabolise lactose, but only some adults can manage the trick. That fact, and the gene involved, have been known for some time. But Dr Moyzis's team have worked out the details of the evolution of LCT. They suspect that it was responsible for the sudden spread of the Indo-European group of humanity about 4,000 years ago, and also for the more recent spread of the Tutsis in Africa, whose ancestors independently evolved a tolerant version of the gene.
The pressures behind other changes are less obvious. In the past 2,000-3,000 years, for example, Europeans have undergone changes in the gene for a protein that moves potassium ions in and out of nerve cells and taste buds. There have also been European changes in genes linked to cancer and Alzheimer's disease. Chinese, Japanese and Europeans, meanwhile, have all seen changes in a serotonin transporte
Source: The Economist
Evolution, as a science, is something that can make predictions, be tested, and be studied in an objective, scientific manner. Research like this is the fruit of making testable predictions — and further demonstrates just how little creationists tend to know about the subject. Creationism, even in the modern guise of Intelligent Design, fails to make any testable predictions and so of course fails to produce any new knowledge about our world. Intelligent Design and creationism are religious ideologies, not scientific theories, no matter what religious apologists try to say. That creationists are unable or unwilling to accept this simple reality is a real problem for the future of science in America.