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.
- 150 years later, schools are still a battlefield for interpreting Civil War
- Where are America's memorials to pain of slavery, black resistance?
- Richmond split over Confederate history
- The World's Jewish Population Is Nearing Pre-Holocaust Levels
- Bernie Sanders’s Revolutionary Roots Were Nurtured in ’60s Vermont
- Did a historian who said he’s a victim of McCarthyism get the story wrong?
- Stephanie Coontz’s work on the history of marriage cited by the Supreme Court.
- NYT History Book Reviews: Who Got Noticed this Week?
- David Hackett Fischer wins $100,000 prize for lifetime achievement in military writing