Sad, but somehow beautiful

Imagine 4600 years ago near Eulau, Germany. A tribe or a settlement was viciously attacked and many were killed. Men, women, children. The survivors returned to bury the dead, these were the people they had lived alongside and maybe grown up among. Thirteen individuals have been found buried so far, interred with social knowledge and respect. One woman has a flint arrow head embedded in her back. Another has two huge blows to the top of her head, either one would have been fatal. Many have arm wounds, an indication they were trying to defend themselves but were unarmed or surprised. We will never know what happened, but the researchers* themselves describe it as "a strong indicator of lethal aggression".


Photo credit: PNAS

The remains have been analysed for DNA and for levels of the element Strontium. Specifically reported are mitochondrial DNA (mtDNA) and Y-chromosome DNA.

mtDNA is passed on from mother to child, both boys and girls, but only the girls can be mothers to pass it on again. The Y-chromosome is passed only from father to son.

In one grave are three children and one female adult. This was the lady who had her head smashed twice, but by mtDNA she is not the mother of two of the youngsters, the lineage of the third is currently unknown. What happened here and why bury them together? A paternal aunt maybe? A childminder with her charges?

The family unit is below the belt. It reminds me of this discovery.

Credit: Proceedings of the National Academy of Sciences/PNAS

At the top is an impression of how the bodies were laid out. The square symbols denote males, the circle is a female. The colours show blue for the male (Y-DNA) and pink or orange for the female (mtDNA) lineages. So the father and mother were definitely unrelated. His mtDNA (orange) comes from his mother's line, hers (pink) from her different maternal history.

The two male children are without question this couple's offspring, they carry their mother's mtDNA (pink) and their father's Y-DNA (blue), but the deliberate placing of the bodies says much. Daddy's favorite son, mom's little soldier, who knows? The people who buried them I suppose, but there would have been a reason.

Ah strontium and you thought I had forgotten. I always associate strontium with red fireworks and, in its radioactive form together with caesium, a nutritional hazard post Chernobyl but that's the point. From Wikipedia:

Since Strontium is so similar to calcium, it is incorporated in the bone. All four isotopes are incorporated, in roughly similar proportions as they are found in nature... However the actual distribution of the isotopes tends to vary greatly from one geographical location to another. Thus analyzing the bone of an individual can help determine the region it came from. This approach helps to identify the ancient migration patterns as well as the origin of commingled human remains in battlefield burial sites. Strontium thus helps forensic scientists too.

By measuring strontium isotope ratios, in this case from teeth which are laid down in childhood, the research shows that the men and women were raised in different places. This implies inter-tribal contact for the purpose of choosing a spouse, and further implies an understanding of the problems associated with inbreeding.

A fascinating study.

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*Reference:
PNAS doi: 10.1073/pnas.0807592105
"Ancient DNA, Strontium isotopes, and osteological analyses shed light on social and kinship organization of the Later Stone Age", Haaka et al, PNAS, Nov 2008.

Supporting information.