Smithsonian seems to be blaming the (ahem) efficiency of “least-effort strategies” on the fall of Homo erectus, modern humans’ recent ancestor:
In a statement, lead author Ceri Shipton, an archaeologist at [Australian National University], notes that the primitive peoples “really don’t seem to have been pushing themselves.”
He adds, “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.”
The ANU team discovered that the early humans who had inhabited the Saffaqah site made stone tools out of whichever rocks happened to be lying nearby, ignoring quality in favor of convenience. A nearby outcrop would have provided better quality stones, but because access required extraneous climbing, H. erectus settled for pieces of rock that rolled down and landed at the bottom of the hill.
When the archaeologists ventured to the top of the outcrop, they found no evidence of H. erectus’ presence.
“They knew it was there, but because they had enough adequate resources they seem to have thought, ‘why bother?’,” Shipton says.
As the region’s rivers dried up, creating the dry Saudi Arabian desert seen today, Shipton theorizes that H. erectus was unable to locate increasingly scarce water. Ultimately, the environment simply became too dry to sustain its population.
Laziness and conservative tendencies — as represented by the consistent use of least-effort tool-making strategies despite a changing environment — likely exacerbated the species’ downfall.
“They were very short term in their view,” Shipton tells Healy. “They would be just planning just a few hours, perhaps a day ahead at most, whereas Homo sapiens and Neanderthals [did] things like target seasonal migration, so they’re planning perhaps for the year ahead.”