Study Detects Recent Instance of Human Evolution
The finding is a striking example of a cultural practice — the raising of dairy cattle — feeding back into the human genome. It also seems to be one of the first instances of convergent human evolution to be documented at the genetic level. Convergent evolution refers to two or more populations acquiring the same trait independently.
Throughout most of human history, the ability to digest lactose, the principal sugar of milk, has been switched off after weaning because there is no further need for the lactase enzyme that breaks the sugar apart. But when cattle were first domesticated 9,000 years ago and people later started to consume their milk as well as their meat, natural selection would have favored anyone with a mutation that kept the lactase gene switched on.
Such a mutation is known to have arisen among an early cattle-raising people, the Funnel Beaker culture, which flourished some 5,000 to 6,000 years ago in north-central Europe. People with a persistently active lactase gene have no problem digesting milk and are said to be lactose tolerant.
comments powered by Disqus
DeWayne Edward Benson - 12/12/2006
Evelution can be cause of many things, as this old Christian has discovered.
I worked all during my lifetime, as a result calluses evolved on the palms of my hands.
I also have evolved a wart, but I blame this on my environment. Some call it a blemish, but I call it damage of DNA at the cellular level. Thankfully it was not passed along to the children.
- Archaeologists Take Wrong Turn, Find World’s Oldest Stone Tools
- Evidence of Pre-Columbus Trade Found in Alaska House
- Rwanda Pullout Driven by Clinton White House, U.N. Equivocation
- Centuries of Italian History Are Unearthed in Quest to Fix Toilet
- The U.S. Discovery of Israel's Secret Nuclear Project