But around 8,000 years ago in what's now Turkey — just when humans were starting to milk newly domesticated cows, goats and sheep — mutations near the gene that produces the lactase enzyme started becoming more frequent. And around the same time, adult lactose tolerance developed.Dec 28, 2012
What type of evolution is lactose tolerance?
Evolutionary history. According to the gene-culture coevolution hypothesis, the ability to digest lactose into adulthood (lactase persistence) became advantageous to humans after the invention of animal husbandry and the domestication of animal species that could provide a consistent source of milk.
Did lactose tolerance evolve more than once?
Culture had dramatic effect on our ability to digest lactose Now, a new study indicates that the ability to digest milk arose more than once in humans descended from cattle herders–a finding that sheds light on how culture can have a rapid and dramatic effect on our genome.
How many times did lactose tolerance evolve?
Still today, most of the world's population can only tolerate milk for the first few years of life. But, through at least four parallel evolutions starting several thousand years ago, lactase persistence spread throughout human populations. One of these, the earliest, is known to have originated in Europe.
How is the development of lactose tolerance an example of coevolution?
Transition to Dairy Foods. A classic example of gene-culture coevolution is lactase persistence (LP) in human adults. Milk contains a sugar named lactose, which must be digested by the enzyme lactase before it can be absorbed in the intestine.
Why is lactose tolerance called lactase persistence?
Some humans do not turn off lactase expression during childhood, and continue to produce considerably quanities of the enzyme into adulthood. This trait is called lactase persistence and allows those individuals to tolerate consumption of lactose sources, including milk.
What is lactase persistence quizlet?
– breaks down lactose, which is found in milk. define lactase persistence. – the ability to produce lactase and digest lactose.
What race is least lactose intolerant?
How many people are lactose intolerant? Estimates for lactose intolerance vary by ethnicity. African American and Asian ethnicities see a 75% – 95% lactose intolerance rate, while northern Europeans have a lower rate at 18% – 26% lactose intolerance.
What race is the most lactose intolerant?
Lactose intolerance in adulthood is most prevalent in people of East Asian descent, with 70 to 100 percent of people affected in these communities. Lactose intolerance is also very common in people of West African, Arab, Jewish, Greek, and Italian descent.
Why lactase tolerance is an excellent example of the co evolution of genes and culture?
Conversely, the genetic makeup of human populations may influence the cultural ideas and practices they adopt. In other words, genes and cultures coevolve. Lactase persistence, the ability to digest lactose and therefore to drink fresh milk after the nursing period, exemplifies the process of gene-culture coevolution.