Radiocarbon dating using a new method has provided the most accurate age assessment yet for the Lapedo Child, a prehistoric skeleton exhibiting both modern human and Neanderthal features. The remains were precisely dated to around 28,000 years ago, shedding new light on prehistoric burial practices and human evolution, according to Live Science.
Using a technique called compound-specific radiocarbon analysis (CSRA), researchers determined that the Lapedo Child lived between 27,780 and 28,850 years ago. Determining the exact age of the child had been challenging due to contamination and poor preservation of the remains. Scientists had previously attempted to estimate the Lapedo Child's age using radiocarbon dating methods, but each of the four prior attempts failed due to contamination from small roots and other sources.
"Successfully dating the child felt like giving them back a tiny piece of their story, which is a huge privilege," said Bethan Linscott, a geochemist at the University of Miami and the study's first author. Linscott further explained that the minimal amount of collagen extractable from the bones, combined with contamination, rendered previous dates unreliable.
In 1998, researchers exploring the Lapedo Valley in central Portugal discovered a rock shelter at the base of a cliff containing the nearly intact, ochre-stained skeleton of an ancient child. Alongside the remains were items such as pierced shells and animal bones, possibly used in a burial ritual. The child was estimated to be around four years old at the time of death.
The Lapedo Child has confounded scientists for nearly 30 years due to its combination of traits from both modern humans and Neanderthals, suggesting it was a hybrid individual. This finding was a radical notion at the time and was not immediately accepted as a valid interpretation. "When the child was discovered, scientists noted that some of the child's attributes, including body proportions and jawbone, looked Neanderthal, and the occipital region of the Lapedo Child was pitted, recalling Neanderthal features," Popular Science reported.
The discovery predates the sequencing of the Neanderthal genome by a decade. Since then, ancient DNA analyses have confirmed that Neanderthals and modern humans interbred multiple times over thousands of years. Researchers have suggested that the Lapedo Child was descended from populations in which modern humans and Neanderthals mated and mixed.
"While we do not have any genetic evidence from Lagar Velho, providing additional confirmation on the age of the site allows us to better understand, on the basis of morphology, how the process of replacement of Neanderthals by Homo sapiens may have played out," said Adam Van Arsdale, a paleoanthropologist at Wellesley College who was not involved in the study.
The new dating has also provided insights into the burial practices of prehistoric populations. The researchers determined that some items found with the child, such as red deer bones and charcoal, were much older, suggesting they were already present at the site when the child was buried.
However, the rabbit bones discovered on top of the child were contemporaneous with the Lapedo Child, indicating they may have been placed as an offering before the grave was filled.
"The death of the child may have triggered a declaration of the place as taboo or as unsuitable for mundane hunting activities, leading to people avoiding it until such time as the event faded from social memory," said João Zilhão, an archaeologist at the University of Barcelona. The site was then abandoned for at least two millennia, according to the researchers.
The application of CSRA not only provided a precise date for the Lapedo Child but also demonstrated the potential of this method for other poorly preserved samples that would fail routine pretreatment methods.
"Hydroxyproline dating can be used to recalibrate the timing of human presence across Europe and beyond with precision, and researchers believe it will soon help paleoarcheologists learn much more about humanity's evolutionary past," Gizmodo noted.
The results of the study published in the journal Science Advances are not likely to settle an ongoing debate in the paleoarcheological community regarding the implications of the Lapedo Child's findings.
Researchers continue to investigate the extent of overlap in time between Neanderthals and modern humans, aiming to reveal a more comprehensive timetable of early modern human occupation and migration across Europe.
The article was written with the assistance of a news analysis system.