23 November 2008
World's most ancient nuclear family discovered in Germany
The oldest genetically identifiable nuclear family met a violent death, according to analysis of remains from 4,600-year-old burials in Germany. Researchers say the broken bones of these stone age people show they were killed in a struggle. Comparisons of DNA from one grave confirm it contained a mother, father, and their two children. The son and daughter were buried in the arms of their parents.
Dr Wolfgang Haak, from The Australian Centre for Ancient DNA, in Adelaide, conducted the DNA analysis. He says the scientific evidence supports the idea that they were indeed a family: "We have been inferring the past from the present, but it wasn't necessarily true. Now, we have tested the hypothesis and found that at least one Stone Age nuclear family existed." Haak points out that it is still unknown when nuclear families became common. Prehistorically, people would have died young in childbirth or from disease, potentially making nuclear families unsustainable.
In total, the four graves contain 13 bodies, eight children aged six months to nine years and five adults aged 25 to 60. In two graves, DNA was well preserved, which allowed comparisons between the occupants. One of these contained the nuclear family, while the other grave contained three related children and an unrelated woman. The researchers suggest she may have been an aunt or stepmother.
These stone age people are thought to belong to a group known as the Corded Ware Culture, signified by their pots decorated with impressions from twisted cords. The new findings also suggest an explanation for anomalies in how later Stone Age people in central Europe were buried. Typically, males of all ages rest on their right side, facing south, and women on their left side facing south, but sometimes there are exceptions to this rule. This was the case with the nuclear family, where each child faced north, towards one of the adults with whom their hands entwined. Haak speculates the arrangement may symbolise blood ties.
The care with which the bodies were laid out shows that whoever buried them must have known who they were says Dr Haak. As well as looking at the DNA of each individual the researchers examined deposits of the element strontium in their teeth. Found in rocks and soils, strontium is taken in from food as teeth grow in childhood. It can act as an indicator of where people came from. The children and adult males had the same type of strontium - which was also found locally, but the nearest match to the women's teeth was at least 50km away, suggesting they had moved to the area. Dr Alistair Pike from Bristol University, who carried out the strontium analysis, says this indicates a culture of exogamy or marrying out. "It's a bit like kings and queens in Europe in the past, creating an alliance by marrying out sons and daughters. This creates a bond between communities - useful if your harvest fails or if you need help fighting a war."
The most grisly aspect of the find is the manner of their death. Dr Pike says it was violent. "They were definitely murdered , there are big holes in their heads, fingers and wrists are broken." At least five of the individuals show the effects of a violent attack, one even had the tip of a stone weapon embedded in a vertebra. Examination of the skeletons found that the adults were aged between 25 to 60 years old - old for that period - and the children younger than 13 years old. Several of the adults had partially healed injuries. "These were the old and the injured, children and women. Whatever violence happened that day, they were not capable of fighting," says Haak. He added that it is probable that most of the adults were elsewhere at the time of the attack, perhaps out fighting or working in their fields. Researchers say such violence fits with what we know about life in central Europe at the time - the area had fertile soils, a stable climate and natural access routes. This made it a desirable place to live, but also created competition amongst its inhabitants, leading to violent confrontations when one community tried to displace another.
Source: NewScientist (17 November 2008), BBC News, Mail Online (18 November 2008)