A 6-year-old Neanderthal child had Down syndromsuggests a new analysis of an oddly shaped ear bone found in a cave in Spain.
The finding is the first known case of Down syndrome in Neanderthalsour closest human relatives who lived in Eurasia between 400,000 and 40,000 years ago. The fact that the child, nicknamed Tina, lived into early childhood suggests that her Neanderthal group took care of her, which is evidence that Neanderthals exhibited altruistic behavior.
“This child would have required at least six years of care, which would likely have required assistance from other group members in child care,” the researchers wrote in a new study published Wednesday (June 26) in the journal Scientific advances.
The ear bone was first excavated in 1989 in Cova Negra (Spanish for “Black Cave”) in Xàtiva, a city in the province of Valencia. Other Neanderthal remains in the cave date from between 273,000 and 146,000 years ago. However, the bone – a fragment of a temporal bone – was mixed with animal remains and was only recently identified, the researchers said.
Related: “More Neanderthal than human”: How your health could depend on the DNA of our long-lost ancestors
The team used a micro-CT (computed tomography) to scan the bone, allowing them to create a digital 3D model of it.
Tina’s ossicle had an irregular shape consistent with Down syndrome, the team found. It also had other unusual aspects, including a smaller cochlea and abnormalities in the lateral semicircular canal (LSC), the shortest of the three ear canals, which together can lead to hearing loss and severe dizziness, according to a opinion.
However, since people with Down syndrome have an extra copy of chromosome 21, a genetic test would have to be carried out to determine with certainty whether Tina actually suffers from this disease.
If this was the case, Tina’s condition likely required care from multiple people in her group, the team said.
It was already known that Neanderthals took care of sick members in their social groups. However, all known individuals who were cared for were adults, so it was unclear whether Neanderthals only cared for those who could help them in return or whether they did so out of altruism.
Since a six-year-old with a difficult genetic disease would not have been able to help much in return, it is likely that the Neanderthals’ help was given for altruistic reasons, the team said.
“What was previously unknown was a case in which an individual received help even if he could not return the favor, which would prove the existence of true altruism in Neanderthals,” said the lead author of the study. Mercedes CondeProfessor at the University of Alcalá in Spain, said in a opinion“That’s exactly what the discovery of ‘Tina’ means.”
The findings are also relevant for modern humans.
“The presence of this complex social adaptation in both Neanderthals and our own species suggests a very ancient origin within the genus. homo“, the researchers wrote in the study.
