An 800,000-year-old skeleton of an ancestral species to modern humans belonged to a woman and not a man, as previously believed, new research has shown.
The sex change for the skeleton, formerly known as the Gran Dolina Boy, came after researchers used modern techniques to analyze dental tissue and found it belonged to a girl between nine and 11 years old.
The skeleton is an example of Homo antecessor – believed to be the last common ancestor shared by Homo sapiens and Neanderthals before the two species split.
The remains were found at the Spanish archaeological site of Grand Dolina in the 1960s and were later found to have died after being killed and eaten by a rival tribe.
Scientists had no idea what the actual sex was until this study, with the concept that it was a boy, taken from a children’s book about the excavation site written by José Maria Bermúdez de Castro in 2002 called El Chico De La Gran Dolina.
“At the time it was not known to which genus this fossil belonged, so a male name was chosen, but it could have been a female name,” said study author Cecilla Garcia.
An 800,000-year-old skeleton of an ancestral species to modern humans belonged to a woman and not a man, as previously believed, new research has shown. Artist impression
DETERMINING SEX BY DENTISTRY
The gender of the ‘Girl of Gran Doline’ was estimated by the Dental Anthropology Group of the Centro Nacional de Investigación de la Evolución Humana (CENIEH).
It was achieved by studying the proportions of the tooth tissue in the canines of these ancient human fossils.
The dimensions of the enamel and dentin in these dental pieces are sexually dimorphic features.
In other words, they make it possible to distinguish between male and female individuals within a population.
For this reason, these parameters have previously been used to estimate gender in forensic samples, where they reach an accuracy of up to 92.3%.
The new study, by Garcia and colleagues at the Dental Anthropology Group at the Centro Nacional de Investigación de la Evolución Humana (CENIEH), is the first to estimate the sexes of two of the most complete fossils found at the excavation site.
Using modern techniques, they examined the remains of individual H1, from which the species Homo antecessor was defined, and the individual H3, previously believed to be a girl because of the children’s book at the dig site.
The results showed that the canines of the two individuals show differences similar to those between modern men and women.
‘This made it possible to determine that H1 was probably male, while the fossil H3 was probably female,’ explains Carcia.
The human remains found on Gran Dolina have been analyzed by many researchers, although it has not been possible to identify gender differences until now.
This is because the majority of individuals were immature, meaning they had not yet reached adolescence, which makes estimating their gender difficult.
Plus, there’s the difficulty posed by having only small skeletal fragments available, rather than a complete set of bones, they added.
“Until now, we only knew the sex of one tooth fragment, from which enamel proteins were obtained,” added co-author José María Bermúdez de Castro.
The skeletal sex change, formerly known as Gran Dolina’s boy, came after researchers used modern techniques to analyze dental tissue
“This study by our group now opens up a new and very reliable way to estimate sex through a non-destructive method.”
Sex estimation was achieved by studying the proportions of the tooth tissue in the canines – the enamel and dentin dimensions.
This is because the dimensions of these are sexually dimorphic traits, meaning that they differ between males and females of a species.
For this reason, this technique has been used in the past to estimate gender in forensic samples – with an accuracy of 92.3 percent and in fossil samples.
Teeth offer the added benefit of completing their formation at an early stage, and therefore they can estimate sex even in immature individuals.
The team said this was a particularly helpful point in the field of paleoanthropology.
For the first time, they were able to confirm that the remains of Gran Dolina’s individual H3 belonged to a girl between 9 and 11 years old.
The skeleton, found in Gran Dolina, in a cave (photo), is an example of Homo antecessor – believed to be the last common ancestor shared by Homo sapiens and Neanderthals
The remains were found at the Grand Dolina Spanish archaeological site in the 1960s, and were later found to have died after being killed and eaten by a rival tribe.
“This individual is represented by a partial face and a fragment of the frontal bone, although this usually appears in photographs along with a lower jaw found in 2003, which, strangely enough, is very likely considered to be female,” explains García.
Gran Dolina’s girl probably had a stature and body proportions comparable to that of a modern girl her age, although it may be that she developed earlier.
While not much is known about what her life would have been like more than 800,000 years ago, we do know a little about how her story ended.
The remains found at Gran Dolina, including that of the girl, show clear evidence of cannibalism, likely the result of a showdown between rival groups.
The findings are published in the Journal of Anthropological Sciences
WHO WERE THE GAY ANTECESSORS?
A lifelike model of a Homo antecessor female is posed and extracts the brain of the decapitated head
Homo antecessor is one of the earliest known human varieties discovered in Europe, dating as far back as a million years ago.
The Homo antecessor would have weighed about 14 stones and would have been between 5.5 and 1.8 meters long.
Their brain sizes were roughly between 1,000 and 1,150 cm³, which is smaller than the average 1,350 cm³ brain of modern humans.
The species is believed to have been right-handed, which makes it different from other monkeys, and may have used a symbolic language, according to archaeologists who found remains in Burgos, Spain, in 1994.
How Homo antecessor can be related to other Homo species in Europe is a hot topic of debate.
Many anthropologists believe there was an evolutionary link between Homo ergaster and Homo heidelbergensis.
Archaeologist Richard Klein claims that Homo antecessor was a completely separate species, evolving from Homo ergaster.
However, others argue that Homo antecessor is actually the same species as Homo heidelbergensis, which lived in Europe between 600,000 and 250,000 years ago in the Pleistocene.
In 2010, stone tools were found at the same site in Happisburgh, Norfolk, believed to have been used by Homo antecessor.
Scientists believe these early human species would regularly breed with each other.
Dr. Matthias Meyer, a paleogeneticist at the Max Planck Institute for Evolutionary Anthropology, in Leipzig, Germany, said, “The evolutionary history of archaic humans in the Middle Pleistocene was quite complex.
It may be that both the ancestors of the Sima people and the Denisovans interbred with another archaic group such as Homo antecessor or Homo erectus.
“Or it is possible that the mitochondrial DNA we know from late Neanderthals came from another group that left Africa.”