Climate change likely played a major role in the extinction of early human species, according to a modeling study published Friday that researchers say serves a “thunderous warning” to humans today.
Of the six or more different species of early humans, all of which belong to the genus Homo, only Homo sapiens managed to survive.
The study, published in the journal One Earth, combined climate modeling and fossil record to look for clues to all those previous extinctions of our ancient ancestors.
“Our findings show that … earlier Homo species could not survive intense climate change,” said Pasquale Raia of the Universita di Napoli Federico II in Italy.
This is despite technological innovations including the use of fire and sophisticated stone tools, the formation of complex social networks and – in the case of Neanderthals – the production of glued spearheads, appropriate clothing and a good amount of cultural and genetic exchange with Homo sapiens, explained Raia explains.
“They did their best; they looked for the hottest places within reach when the climate turned cold, but at the end of the day that wasn’t enough, ”he said.
The finding may serve as a kind of warning to humans today as we face unprecedented changes in the climate, the researchers said.
To shed light on the extinction of Homo species in the past, including H. habilis, H. ergaster, H. erectus, H. heidelbergensis, H. neanderthalensis, and H. sapiens, they relied on a past climate emulator with high resolution, which provides temperature, rainfall and other data for the past 5 million years.
The team also analyzed an extensive fossil record that included more than 2,750 archaeological records to model the evolution of the climatic niche of Homo species over time.
Their findings provide robust evidence that three Homo species – H. erectus, H. heidelbergensis and H. neanderthalensis – lost a significant portion of their climatic niche just before their extinction.
This reduction coincided with sharp, unfavorable changes in the global climate, the researchers said.
In the case of Neanderthals, things were likely made worse by competition with H. sapiens, they said.
“We were surprised by the regularity of the effect of climate change,” said Raia.
“It was crystal clear, to the extinct species and only to them, that the climatic conditions were just too extreme just before extinction and only at that particular time,” he added.
The researchers noted that it is worrying to find that our ancestors, no less impressive in terms of mental strength compared to other species on Earth, could not withstand climate change.
“And we found that just when our own species is cutting the branch, we are causing climate change. I personally consider this a thunderous warning message.
According to the study, the early human species are threatened with extinction due to climate change
Previous Homo species could not survive intense climate change