Couch potatoes beware: Laziness led to extinction of prehistoric menAug 12 (AZINS) Laziness, paired with an inability to adapt to a changing climate, may have wiped out the Homo erectus, an extinct species of primitive humans, a study has found.

An archaeological excavation of ancient human populations in the Arabian Peninsula during the Early Stone Age, found that Homo erectus used 'least-effort strategies' for tool making and collecting resources.

"They really don't seem to have been pushing themselves," said Ceri Shipton, from the Australian National University (ANU).

"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," said Shipton.

This was evident in the way the species made their stone tools and collected resources.

"To make their stone tools they would use whatever rocks they could find lying around their camp, which were mostly of comparatively low quality to what later stone tool makers used," he said.

"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," he added.        

This is in contrast to the stone tool makers of later periods, including early Homo sapiens and Neanderthals, who were climbing mountains to find good quality stone and transporting it over long distances.