July 22, 2024

A Neanderthal child with Down syndrome survived to at least age six, according to a new study whose findings point to compassionate care among the extinct, archaic human species.

Recent examination of a human fossil excavated at the Cova Negra archaeological site in the Spanish province of Valencia has found features in the inner ear anatomy suggestive of Down syndrome, in the earliest known evidence of the genetic condition.

The fossil, which preserves the complete inner ear anatomy, was unearthed in 1989, but its significance was not recognized 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 can’t be sure if the fossil was that of a girl or a boy, they named the Neanderthal child “Tina.”

Tina’s combination of inner ear abnormalities is only known in people with Down syndrome.

“The pathology that this individual suffered led to extremely disabling symptoms, including, at least, complete deafness, severe vertigo attacks and an inability to maintain balance,” said Mercedes Conde-Valverde, a paleoanthropologist at the University of Alcalá in Spain, said. main 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 survive for at least six years, the group must have continuously assisted the mother, either by relieving her in the care of the child, helping her with her daily tasks, or both,” said Conde- Valverde added.

Among other pathologies, there were abnormalities in the semicircular canals – three small tubes that control balance and sense head position – and a reduction in the size of the cochlea, the part of the inner ear involved in hearing.

The exact age of the fossil has not been determined, but Conde-Valverde noted that the presence of Neanderthals at the Cova Negra site have been dated to between 273,000 and 146,000 years ago.

Gay neanderthalensisas Neanderthals is formally called, is more robustly built than Homo sapiens and had bigger eyebrows. They lived from about 430,000 years ago to about 40,000 years ago. Previous research has shown that Neanderthals were intelligent, creating art, pigments, symbolic objects and perhaps a spoken language, as well as using complex group hunting methods.

They disappeared relatively soon after our species spread into their area.

Previous evidence of Neanderthals caring for their sick and injured provoked a debate about whether it was motivated simply by expectations of reciprocal behavior or by genuine compassion.

“For decades, Neanderthals have been known to care for and care for their vulnerable companions,” Conde-Valverde said. “However, all known cases of care involved mature individuals, leading some scientists to believe that this behavior was not genuine altruism, but simply an exchange of help between equals.

“Until now, what was not known was a case of an individual who received extramaternal 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 suggests that 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 state of maturation 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 care, probably more extensive than parental care, typical of a highly cooperative social context among the members of the group. Otherwise, it is very difficult to explain the survival of this individual 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.”

Source link

Leave a Reply

Your email address will not be published. Required fields are marked *