A ferocious battle took place in what is now northern Germany about 3,000 years ago, and, as Science reports, researchers analyzed the DNA of individuals who died during the battle to gain insight into its cause.
But as an international team of researchers reports in Current Biology, the analysis indicated that the Tollense fighters were mostly male and all were from Central or Northern Europe, a finding that gave little hint as to why the Bronze Age battle occurred. "We were hoping to find two different groups of people with different ethnic backgrounds, but no," co-author Joachim Burger from the Johannes Gutenberg University of Mainz tells Science. "It's disappointingly boring."
He and his colleagues did find, however, that these 3,000-year-old fighters could not digest milk. This finding, Science notes, contradicts previous hypotheses and instead suggests lactase persistence was under very strong selection. The researchers found the lactase persistence gene spread very quickly in Europe to become established within 100 generations, but why there was such strong selection is as yet unclear.