Spread of farming. the origin of lactase persistence in Neolithic Age

The processing of milk to make cheese and yogurt contributed significantly to the development of dairy farming, as this represented a way of reducing the lactose content of fresh milk to tolerable levels, making a valuable foodstuff available to the human population.

Until 8,000 years ago, humans were only able to digest lactose, a form of sugar present in fresh milk, during childhood because as adults they lost the ability to produce endogenous lactase, the enzyme required to break down lactose. Shortly before the first farmers settled in Europe, a genetic mutation occurred in humans that resulted in the ability to produce lactase throughout their lives. Increasing numbers of adults in Central and Northern Europe have since been able to drink and digest milk.

“This two-step milk revolution may have been a prime factor in allowing bands of farmers and herders from the south to sweep through Europe and displace the hunter-gatherer cultures that had lived there for millennia,” specifies the article in Nature with reference to the LeCHE project…

Anthropologist Professor Joachim Burger of Johannes Gutenberg University Mainz (JGU) was substantially involved in the establishment of the EU project and its research activities. “To appreciate the significance of our findings, it is important to realize that a major proportion of present-day central and northern Europeans descend from just a small group of Neolithic farmers who happened to be able to digest fresh milk, even after weaning,” explained Burger. His team investigated the phenomenon of lactase persistence, i.e., the ability to break down milk sugar, using skeletons from the Neolithic. “Among the most exciting results obtained by the LeCHE group were the detection of milk fat residues in numerous Neolithic pottery remains and the ability to model the spread of positive selection of lactase persistence,” said Burger.

Just 5,000 years ago, lactase persistence was almost non-existent among populations in which its modern prevalence is greater than 60 percent. The researchers assume that extensive positive selection and recurrent waves of migration were responsible for this development, which — in evolutionary terms — took place extremely rapidly.

I’m not part of that group with lactase persistence. It only seems to affect me, though, if I get foolish enough to attempt ice cream.

Half my genes are from the northern climes where the spread of farming exploded – still, I managed to miss out. Fortunately, like many with lactose intolerance, I have no problem consuming yogurt – especially low fat varieties – and more cheese than I ever really need. :)

About eideard

Lifetime political activist. Cranky old Geek. Green. Progressive.
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4 Responses to Spread of farming. the origin of lactase persistence in Neolithic Age

  1. dropsy says:

    Lactase persistence is also seen in some parts of Africa – is that a different genetic mutation?

    • eideard says:

      My guess is – probably. Probably – in that while technically it may be the same kind of mutation, the several dialectic journeys forth and back between Africa and Euro/Asia predate neolithic farming in northern Europe.

      OTOH, the quantitative matrix from which the mutation arose may have been identical and original to earlier periods of evolution in Africa.

      Great questions for discussion – but, with someone with close knowledge of the topic. Which ain’t me.

  2. Meanwhile says:

    A mass grave in Germany underscores what some archaeologists have long suspected: The first farmers were far from peaceful tillers of the soil. In a newly discovered form of Neolithic violence, attackers 7000 years ago systematically broke the shinbones of their 26 victims, many of them children, before dumping their bodies in a pit.
    The first farmers, who spread west from Anatolia (modern-day Turkey) to arrive in central Europe 7500 years ago, lived more settled lives than the nomadic fishing and foraging peoples they displaced. They built houses, cultivated plants, and decorated pottery. But researchers have long debated whether these Neolithic farming communities also engaged in warfare and other types of systematized violence. http://news.sciencemag.org/archaeology/2015/08/archaeologists-uncover-neolithic-massacre-early-europe

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