humans still evolving
via
kultureflash
Where do we go from here?
- The Guardian,
- Saturday December 15 2007
(...) The question of whether modern humans are evolving has not gone away, though. This week, scientists added to a growing pile of papers that indicate human evolution is not only continuing, but may be accelerating at an unprecedented pace. Where this will take us has become one of the most contentious questions in evolutionary biology.
(...)
In an essay entitled The Spice of Life published in 2000, the late evolutionary biologist Stephen Jay Gould reinforced the idea that thanks to improvements in medicine, shelter and, for many, plentiful food, humans had all but stepped off the evolutionary ladder. "Natural selection has almost become irrelevant," he wrote. "There's been no biological change in humans in 40,000 years or 50,000 years. Everything we call culture and civilisation we've built with the same body and brain."
This week, Harpending's group published details of a study that asked how much humans have evolved in the past 80,000 years, a period that includes the exodus of humanity from Africa. The answer, they concluded, was an awful lot. They identified a rapid increase in evolution, as our ancestors adapted first to harsh latitudes with miserable climates, then to farming, which revolutionised the human diet. Harpending's group studied the DNA of four distinct groups around the planet: Japanese, Han Chinese, Europeans and Yoruba in Africa. They found that nearly 2,000 genes, or 7% of the genome, have been subjected to recent natural selection.
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