Researchers have performed an updated analysis of an ancient child that was discovered in 1998 in the Lapedo Valley of Portugal. The find was a nearly complete skeleton, which was stained with red ochre. Scientists suspected it was likely wrapped in animal skins before it was buried. The skeleton was particularly striking because it displayed features of both Neanderthals and humans.
An expert analysis suggested that some characteristics of the skeleton, such as its proportions and jawbone, resembled Neanderthals. The child might have descended from a group in which there was mixing, mingling, and mating among Neanderthals and humans. In 1998, this seemed unlikely. But more recent research has shown that in ancient times, there was lots of mixing between Neanderthals and humans, and many modern humans even carry bits of Neanderthal DNA in their genomes.
It was still challenging for investigators to determine when this child lived, however. The skeleton had been contaminated over many years by roots and other material. Therefore, traditional carbon dating methods could not be used to determined the age of the skeleton. But in an attempt to make an estimate, the researchers used stuff like charcoal and animal bones that was found near the skeleton to make a determination. The researchers concluded that the skeleton was between 27,700 and 29,700 years old.
Since then, there have been improvements in dating methods. Researchers used those approaches to make a new estimate of the skeleton's age, and that effort was reported in Science Advances.
With this new approach, called compound-specific radiocarbon analysis (CSRA), the scientists analyzed the amino acids that make up a protein that is present in human bones, called collagen. This technique is meant to eliminate the confounding results that can come from contamination by focusing on a specific part of one molecule. This work confirmed the previous estimate and narrowed the range slightly: the skeleton was found to be about 27,780 to 28,550 years old.
"Being able to successfully date the child felt like giving them back a tiny piece of their story, which is a huge privilege," first study author Bethan Linscott, now of the University of Miami, told The Associated Press.
There is genetic evidence that humans and Neanderthals started interbreeding around 49,000 years ago, and this may have gone on for 6,000 years. So these latest findings may suggest that those mixers went on for longer than we have assumed, or that traits of mingled populations may have persisted.
Sources: The Associated Press, Science Advances
