The human ancestor Homo erectus emerged about two million years ago, and was thought to have all but disappeared by about 300,000 years ago. But now, an international team of scientists has uncovered what may have been the species’ “last stand” in Indonesia. Here, Homo erectus could have survived until as recently as 108,000 years ago.
Homo erectus was one of humanity’s first success stories. This tall, slender hominin emerged in Africa roughly two million years ago, and was one of the first early human species to leave the continent, venturing into Asia and Europe. It’s thought to have mostly disappeared about 300,000 years ago, but not necessarily from dying off – instead, it gradually evolved into other species, giving rise to Neanderthals, Denisovans and modern humans, among others.
But now, a new study has identified the last-known surviving colony of Home erectus, on the island of Java in Indonesia. The site of Ngandong is home to a rich bonebed of fossils, including 12 skull caps and two tibia from Homo erectus. The research team has finally managed to date the bones, and found them to be younger than expected.
The researchers used a series of different dating techniques – including uranium-series dating, luminescence, and electron-spin resonance – on the Homo erectus bones and those of other animal remains in the site, as well as geological features in the area. This gave them 52 individual age estimates, creating a remarkably consistent window of between 108,000 and 117,000 years ago.
“This site is the last known appearance of Homo erectus found anywhere in the world,” says Russell Ciochon, co-corresponding author on the study. “We can’t say we dated the extinction, but we dated the last occurrence of it. We have no evidence Homo erectus lived later than that anywhere else.”
This age range means Homo erectus lived in Indonesia around the same time as Homo floresiensis (the so-called “Hobbits”), and Homo luzonensis in the Phillipines to the north. Interestingly, they may have overlapped more directly with Denisovans in the area, even breeding with them.
“The new age estimates from Ngandong indicate that Homo erectus and the Denisovans probably overlap in the region, or at least met at some time before 100,000 years ago,” says Michael Westaway, an author of the study. “This may mean some of the unique traits that have been recognised in the skulls of very late Homo erectus fossils at places like Ngandong may in fact be a result of a mixture of two archaic populations – Homo erectus and the Denisovans.”
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The research was published in the journal Nature.
Sources: Griffith University, University of Iowa, University of Queensland