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Bronze Age skull in situ in the Tollense valley Source: ©: Stefan Sauer / Tollense Valley Project

Ancient Warriors Show Europeans Were Late Adopters of Dairy Produce

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Research undertaken on Bronze Age warriors who died in a battle in Germany has revealed something remarkable about the evolution of human digestion. It established that it is only in the past few thousand years that people have been able to tolerate lactose, and in other words, consume dairy products. These findings show that something that we take for granted, is a relatively new phenomenon.

Palaeogeneticists from the Johannes Gutenberg University , Mainz in Germany studied the bones of warriors slain in perhaps the earliest known battle in European history and certainly the oldest one north of the Alps. Sometime around 1200 BC, several thousand men, some on horseback, battled each other, along the Tollense River. Since the battlefield was first discovered in the 1990s, more than 100 human remains with signs of violent trauma have been found. Mainz University reports that ‘Many still contain arrowheads , while some skulls look to have been crushed by blunt objects’.

So far, bones from more than 100 individuals have been discovered on the battlefield. (©: Stefan Sauer / Tollense Valley Project)

So far, bones from more than 100 individuals have been discovered on the battlefield. (©: Stefan Sauer / Tollense Valley Project)

Bronze Age warrior’s genetics

The victims of the prehistoric combat offered the geneticists a unique opportunity. They were looking for the gene that enables Lactase persistence (LP) that allows humans to tolerate and digest lactose which is present in milk (and so all dairy produce ). When we are infants the gene is present that allows us to digest breast milk, but this is often lost in adulthood. Having a high LP means that an individual can continue to digest milk and its by-products.

The palaeogeneticists examined the DNA of the slain Tollense warriors for the gene that allows adults to consume milk and its by-products. DNA analysis showed ‘Genetic data indicate that these individuals represent a single unstructured Central/Northern European population’ the researcher wrote in Current Biology . Some 27 samples were used in the study to search for the genetic mutation that helps humans as adults to consume dairy products.

Based on the data from the Tollense battle dead, it was found that only ‘only one in eight had a gene that breaks down lactose - a type of sugar in milk’ reported the researchers. This was astonishing in that some 90% of the people living in this part of Germany, today, are lactose tolerant. Yet, apart from a few genetic variations, those who died in the Bronze Age had much the same genetics as the modern inhabitants of the valley.

Archaeologists have been systematically searching a section along the Tollense river for more than 10 years. (©: Stefan Sauer / Tollense Valley Project)

Archaeologists have been systematically searching a section along the Tollense river for more than 10 years. (©: Stefan Sauer / Tollense Valley Project)

Survival of the fittest

Professor Joachim Burger, lead author of the study, said that ‘this was a huge difference when there can't have been more than 120 generations of humans between then and today’ according to the press release. It appears that people evolved the ability to tolerate lactose in a relatively short period, from a genetic perspective. This was an eye-opener for the experts. They checked their findings with Bronze Age bones found in Eastern Europe and these results corroborated their findings.

The reason for this is probably natural selection. Professor Daniel Wegmann, of the University of Fribourg, stated that, ‘We conclude that over the past 3,000 years, lactase-persistent individuals had more children or, alternatively, those children had better chances of survival than those without this trait’ according to the Mainz University website press release.

It is estimated that those who had the gene that could break down lactose, and therefore consume milk, had a better chance of living to adulthood and having children. They had a better chance of surviving food shortages, which were common, and by drinking milk they did not consume contaminated water. This could account for the fact that more people today are lactose tolerant when their ancestors were lactose intolerant.

Discovery of a mandible in the Tollense river. (©: Ronald Borgwardt / Tollense Valley Project)

Discovery of a mandible in the Tollense river. (©: Ronald Borgwardt / Tollense Valley Project)

Immigrants and genetic changes

In 2007, members of the team established that none of the first farmers in Europe was able to tolerate milk. Burger is quoted by the Mainz University website as saying that ‘It is astonishing that at the time of the battle at the Tollense, more than 4,000 years after the introduction of agriculture in Europe, lactase persistence in adults was still so rare’.  The researchers wrote in Current Biology that ‘during the Bronze and Iron Ages long after humans started consuming milk from domesticated animals’ most people in this area were still lactose intolerant.

One theory proposed was that immigrants led to an increased number of Europeans who could digest milk until they became predominant in the population. In Current Biology ‘This rapid rise has been attributed to an influx of people from the Pontic-Caspian steppe that began around 5,000 years ago’. This resulted in more people having lactase persistence in adulthood over time.

But it is worth noting that in an earlier report this year , Ancient Origins covered the finding that dairy farming ‘didn’t really take off’ around Europe, whereas 80% of Neolithic pottery samples from Britain and Ireland contained dairy products.

Top image: Bronze Age skull in situ in the Tollense valley Source: ©: Stefan Sauer / Tollense Valley Project

By Ed Whelan

References

J. Burger et al., Low prevalence of lactase persistence in Bronze Age Europe indicates ongoing strong selection over the last 3,000 years,  Current Biology , 3 September 2020,
DOI:10.1016/j.cub.2020.08.033

Comments

Bruce Nowakowski's picture

Was the DNA lineage comparissons Matriarichal or Patriarchial?   It is possible that the invading force from the Steppe intermarried with the females in the region passing on the lactose tolerant gene in subsequent generations which would account for the rapid increase. 

Bruce Nowakowski's picture

So rather than comment on the article you would rather spread propaganda? 

In my little world nobody is dairy produce tolerant. If it is lactose we are talking about then ditto for lactose.

We are the only animal on this world that willingly drink milk destined for an entirely different species.and when we are adults (post weaned) to boot. Only baby cows drink cows milk or can tolerate cows milk.

Ever smelt the boot of a car on a hot day when the milk carton burst a few hours ago, this is how you smell after drinking milk but the smell emanates from your skin for days after. You cannot smell this if you are a milk drinker yourself.

Is this just another article that attempts to convince me of evolution.

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