PUBLISHED: 10:19, Fri, Oct 16, 2020 | UPDATED: 10:20, Fri, Oct 16, 2020
At least six species of early human walked the Earth nearly three million years ago, of which Homo sapiens is the only one to have survived. Multiple theories have been put forward to explain their gradual extinction with a new study published in the journal One Earth suggesting climate change played a major role in shaping the evolutionary history of life on Earth. The study proposes the inability to adapt to a warming or cooling climate sealed the deal on their fate.
Study co-author Pasquale Raia of the University of Naples Federico II in Naples, Italy, said: "Our findings show that despite technological innovations including the use of fire and refined stone tools, the complex social networks, and - in the case of Neanderthals - even the production of glued spear points, fitted clothes, and a good amount of cultural and genetic exchange with Homo sapiens, past Homo species could not survive intense climate change.
"They tried hard; they made for the warmest places in reach as the climate got cold, but at the end of the day, that wasn't enough."
The study combined climate models with the data from the fossil record to analyse what happened to past members of the Homo genus.
These include Homo habilis (handy man), Homo ergaster (working man), Homo erectus (upright man), Homo neanderthalensis (the Neanderthals), Homo Heidelbergensis (Heidelberg man) and Homo sapiens (wise man).
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Climate change may have led to the extinction of prehistoric human species (Image: GETTY)
Climate change: The skulls of four Homo species, including us, Homo sapiens (Image: GETTY)
The researchers' climate models simulated rainfall and temperature data spanning the last five million years.
The study found at least three Homo species - Homo erectus, Homo Heidelbergensis and Homo neanderthalsis - lost a portion of their "climatic niche space" just before they went extinct.
And the researchers believe this coincides with sharp changes in the global climate and an increased vulnerability to these changes.
Professor Raia said: "We were surprised by