Laziness made human ancestors go extinct, suggest scientists

10 August 2018, 14:15

A team of archaeologists have published new research suggesting that one of humanity's potential ancestors, Homo erectus, went extinct because of its laziness.

The team, from the Australian National University (ANU), led an excavation of ancient human populations in the Arabian Peninsula during the Early Stone Age.

Instead of striving for dominance, the team found that Homo erectus had employed a number of "least-effort strategies" to develop tools and collect resources.

Dr Ceri Shipton, who led the research, said that this "laziness" alongside the species' inability to adapt to their changing environment played a role in the species going extinct.

"They really don't seem to have been pushing themselves. I don't get the sense they were explorers looking over the horizon. They didn't have that same sense of wonder that we have," Dr Shipton said.

He added this was evident in the way the species had made stone tools, where they just used "whatever rocks they could find lying around their camp, which were mostly of comparatively low quality to what later stone tool makers used.

"At the site we looked at there was a big rocky outcrop of quality stone just a short distance away up a small hill. But rather than walk up the hill they would just use whatever bits had rolled down and were lying at the bottom.

"When we looked at the rocky outcrop there were no signs of any activity, no artefacts and no quarrying of the stone. They knew it was there, but because they had enough adequate resources they seem to have thought, 'Why bother?'"

This is in stark contrast to later hominids, including early Homo sapiens and Neanderthals, who climbed mountains to find quality tool-stone and transported it over large distances.

There is ongoing debate about how direct an ancestor Homo erectus is to modern Homo sapiens. It was one of the most long-lived species of Homo, potentially living for the two million period covering the last ice age.

Scientific consensus is that Homo sapiens only emerged roughly 300,000 years ago, and due to the rapid evolution of the modern brain quickly became the dominant Homo species.

According to Dr Shipton, this failure for Homo erectus to progress technologically as their environment dried out with climate change contributed to their extinction.

"Not only were they lazy, but they were also very conservative. The sediment samples showed the environment around them was changing, but they were doing the exact same things with their tools," Dr Shipton said.

"There was no progression at all, and their tools are never very far from these now dry river beds. I think in the end the environment just got too dry for them."

The excavation and the survey work that Dr Shipton conducted happened in 2014 in central Saudi Arabia.

The team's research has been published in the scientific journal PLoS One.