The oldest known fossil of a human child with a skull deformity has been discovered, suggesting that early humans did not kill or abandon their abnormal offspring, as has been commonly assumed. A research team reconstructed the 530,000-year-old skull, the first pieces of which were unearthed in Spain in 2001, and determined that the child likely suffered from craniosynostosis, a debilitating genetic disorder in which some pieces of the skull fuse too quickly, causing pressure to build in the brain [Wired] and interfering with brain development. The severity of the deformity is not clear, but researchers say the child probably had learning difficulties and other mental health issues, and certainly would have required extra care.
The child belonged to the species Homo heidelbergensis, who lived in Europe 800,000 years ago and may have been the direct ancestors of Neanderthals. Humans are thought to be unique in the way they care for sick individuals. Researchers call it conspecific care, but most laypeople would probably call it compassion. Other primates don’t display similar behavior, so we know humans evolved the ability at some point, even if scientists can’t quite pinpoint when. The work could mean that humans as far back as half a million years ago had differentiated from our primate ancestors [Wired].
Ana Gracia, lead researcher of the study published in the Proceedings of the National Academy of Sciences, notes that deliberately killing unwanted offspring “is not an uncommon practice among mammals, including great apes,” our closest genetic relatives [National Geographic News]. But anthropologist David DeGusta argues that the “survival of an infant with significant pathology has been observed in a range of primate species.” … Several studies have shown that young, deformed primates were cared for by their mothers anyway, he said. For example, a 1973 paper reported that blind macaque infants were cared for by their mothers for up to a year [Wired].
Some scientists also argue that craniosynostosis does not necessarily cause severe learning difficulties, an uncertainty that Gracia confirmed. She said it’s impossible to know whether the child suffered from any cognitive problems, but he or she would undoubtedly have looked different from family and friends [New Scientist]. And she feels confident in the conclusion that this child would likely have required “special need care” to have lived as long as it did [National Geographic News]. The child was between five and 12 years old when he or she died.
Image: National Academy of Sciences, PNAS