A Neanderthal child with Down’s syndrome survived until at least the age of six, according to a new study whose findings hint at compassionate caregiving among the extinct, archaic human species.
Recent examination of a human fossil unearthed at the Cova Negra archaeological site in the Spanish province of Valencia found traits in the inner-ear anatomy which indicated Down syndrome, in the earliest-known evidence of the genetic condition.
The fossil, which preserves the complete inner-ear anatomy, was excavated in 1989 but its significance was not recognised until recently. It is a fragment of one of the two temporal bones – the right one – that help form the sides and base of the skull, protecting the brain and surrounding the ear canal.
While the researchers cannot be certain whether the fossil was that of a girl or a boy, they have nicknamed the Neanderthal child “Tina.“
Tina’s combination of inner-ear abnormalities is known only in people with Down’s syndrome.
“The pathology which this individual suffered resulted in highly disabling symptoms, including, at the very least, complete deafness, severe vertigo attacks and an inability to maintain balance,” said Mercedes Conde-Valverde, a palaeoanthropologist at the University of Alcalá in Spain, lead author of the study, published in the journal Science Advances.
“Given these symptoms, it is highly unlikely that the mother alone could have provided all the necessary care while also attending to her own needs. Therefore, for Tina to have survived for at least six years, the group must have continuously assisted the mother, either by relieving her in the care of the child, helping with her daily tasks, or both,” Conde-Valverde added.
Among other pathologies, there were abnormalities in the semicircular canals – three small tubes that govern balance and sense head position – and a reduction in the size of the cochlea, the part of the inner ear involved in hearing.
The fossil’s precise age has not been determined, but Conde-Valverde noted that the presence of Neanderthals at the Cova Negra site has been dated to between 273,000 and 146,000 years ago.
Homo neanderthalensis, as Neanderthals are formally called, were more robustly built than Homo sapiens and had larger brows. They lived from about 430,000 years ago to roughly 40,000 years ago. Previous research has shown that Neanderthals were intelligent, and created art, pigments, symbolic objects and perhaps a spoken language, as well as utilising complex group hunting methods.
They disappeared relatively soon after our species spread into their territory.
Previous evidence of Neanderthals caring for their sick and injured prompted a debate over whether this was motivated merely by expectations of reciprocal behaviour or by genuine compassion.
“For decades, it has been known that Neanderthals cared for and looked after their vulnerable companions,” Conde-Valverde said. “However, all known cases of care involved adult individuals, leading some scientists to believe that this behaviour was not genuine altruism but merely an exchange of assistance between equals.
“What was not known until now was a case of an individual who had received extra-maternal care from birth, even though the individual could not reciprocate. The discovery of the Cova Negra fossil supports the existence of true altruism among Neanderthals.”
Archaeological evidence at Cova Negra indicates the site was occupied for short periods at a time by small groups of Neanderthals – hunter-gatherers who roamed the landscape in search of food and other resources. Tina’s age at death, based on the maturation state of certain inner-ear structures, shows unusual longevity for a child in such circumstances with a condition known for intellectual disability and developmental delays.
“The survival of this child, beyond the period of breastfeeding, implies group caregiving, probably more extended than parental caregiving, typical of a highly collaborative social context among the members of the group. Otherwise, it is very difficult to explain the survival of this individual up to the age of six years,” said Valentín Villaverde, a co-author of the study and an emeritus professor of prehistory at the University of Valencia.
Conde-Valverde said: “The discovery of Tina represents the oldest known case of Down syndrome and demonstrates that the diversity observed in modern humans was already present in prehistoric times. This finding ensures that the story of human evolution includes us all.“