Gigantopitecus blacki was a large hominid of more than three meters in height and 500 kilograms in weight that inhabited Southeast Asia until 300,000 years ago. It became extinct during the Pleistocene. Now, a team of scientists from the Institute for Evolutionary Biology (IBE) and the Globe Institute at the University of Copenhagen have managed to recover the oldest molecular evidence on hominin evolution. Did Gigantopithecus belong to the human lineage?
Examination of the oldest biological material extracted from a fossil indicates that Gigantopithecus is directly associated with today’s orangutan, although their association is very distant, the researchers say, based on genetic material extracted from a 1.9-million-year-old fossil tooth. found in southern China in 1935.
Thanks to the new technique used, the researchers have been able to compare the reconstructed fossil proteome -that is, the totality of expressed proteins-, with a database of known hominin proteins, thus being able to identify the position of Gigantopithecus in evolutionary history. and clarifying the mystery of whether or not he belonged to the human lineage. It is clear that this new technique surpasses that of the analysis of old DNA.
The largest primate on the planet
The fossil tooth showed that the world’s largest known ape was a distant, oversized relative of orangutans, a critically endangered species found today only on two islands in Sumatra and Borneo. The new finding will allow researchers, who have succeeded in reconstructing the evolutionary relationship between a two-million-year-old giant primate and the living orangutan, and also accurately rebuild animal evolutionary processes, including humans.
The Gigantopithecus appeared just at the beginning of the line that gave rise to the orangutans.
The mysterious Gigantopithecus blacki , whose fossil remains are so rare, just a collection of teeth and remains of several lower jaws, is the largest primate of the group of mammals that includes lemurs, monkeys, apes and humans.
“Our data, for the first time, provide independent molecular evidence that the closest living relative of Gigantopithecus is the modern orangutan,” explained molecular anthropologist Frido Welker, and leader of the work published in the journal Nature. “Not only do proteins survive, but they survive in sufficient numbers to allow the evolutionary relationships between Giganto and existing great apes to be resolved ,” Welker emphasized.
Paleoanthropologist and study co-author Wei Wang, of Shandong University in China, stated that the evolutionary lineages of the orangutans and Gigantopithecus separated about 12 million years ago, and that the origin and evolution of the creature had puzzled paleoanthropologists for more than half a century.
He added that it was the first time that such ancient genetic material had been recovered from a fossil found in a hot and humid environment, conditions usually inhospitable for such preservation, so experts hope that this same technique could be used on other fossils, perhaps including species in the human evolutionary lineage.
Judging from the decay of fossil teeth, experts conclude that Gigantopithecus, which became extinct about 300,000 years ago for reasons that are not fully understood, was likely herbivorous , based on microscopic plant fossils found in some teeth.
The human species Homo sapiens first appeared about 300,000 years ago in Africa; it later reached Southeast Asia, and the two species were unlikely to meet, the authors say. There was no evidence that other now extinct human species played a key role in the demise of Gigantopithecus and they blame climate and environmental changes for the extinction of the largest primate on the face of the Earth.
According to Welker, the supposed ancestors of Homo sapiens are also mainly found in subtropical areas, which means that we can potentially retrieve similar information about the evolutionary line leading to humans.
Referencia: Frido Welker,Tomas Marques-Bonet, Enrico Cappellini et. al. “Enamel proteome shows that Gigantopithecus was an early diverging pongine”. Nature (13 de noviembre de 2019). DOI: https://doi.org/10.1038/s41586-019-1728-8
