“Experts have long debated the date that humans arrived in Australia,” said LiveScience. Now a study using DNA from both ancient and modern Aboriginal people across Oceania may have finally “settled the debate”.
The study, published last week in Science Advances, looked at an “unprecedentedly large” dataset of nearly 2,500 genomes to determine that humans began to settle northern Australia about 60,000 years ago.
But “even more interestingly”, the study also added to growing evidence that along the way these “early human pioneers likely interbred with archaic humans”, including the species known as “the hobbit”, Homo floresiensis.
Human hobbits
Homo floresiensis “might have been slight in stature”, at just over a metre tall, but its origins have “attracted lengthy debate”, said the Natural History Museum.
At the start of the millennium, most paleoanthropologists believed Homo sapiens was the only human species that had managed to reach Sahul, an ancient landmass that includes modern-day Australia. “It seemed very unlikely that archaic humans had watercraft capable of crossing the ocean.”
But the discovery of Homo floresiensis in 2003 “changed things dramatically”. A team uncovered more than 100 fossils in a cave on “a remote Indonesian island” called Flores, including the partial skeleton of a female: still the most complete Homo floresiensis fossil to date. The adult female was just 1.05 metres tall, earning the species its nickname: the hobbit.
Before the discovery, anthropologists had “assumed that the evolution of the human lineage was defined by bigger and bigger brains”, said anthropology professors Tesla Monson and Andrew Weitz on The Conversation. This, they believed, enabled early modern humans to perform “more complex tasks such as using fire, forging and wielding tools”. The discovery of the hobbits, with their “chimp-sized brain”, forced scientists to throw these theories “out the window”.
So how did they get to Flores?
Stone tools found on the Indonesian island of Sulawesi were recently dated between 1.04 million and 1.48 million years old. That makes them “the earliest evidence ever discovered of ancient humans making a sea crossing”, said New Scientist. These could “provide clues” as to how the tiny hobbits made it to nearby Flores.
At least one of the artefacts was a flake that was struck off a larger flake and then trimmed. “This is a very early kind of human intelligence from a species that no longer exists,” said team member Adam Brumm, from Griffith University in Brisbane. “We don’t know what species it was, but this is a human intelligence behind these stone artefacts at the site of Calio.”
Both Flores and Sulawesi were separated from the mainland by “large expanses of sea”, and it is “almost certain that these early hominins weren’t capable of building ocean-going vessels”. The original population might have been washed out to sea by “some sort of freak geological event” such as a tsunami.
But the late archaeologist Mike Morwood, who led the team that originally identified Homo floresiensis, suggested that Sulawesi was “an important place to search for potential ancestors of the hobbits”.
New research suggests that ‘early human pioneers’ in Australia interbred with archaic species of hobbits at least 60,000 years ago
