Of the six or more different species of early humans, all belonging to the genus Homo, only we Homo sapiens have survived. Now, a study reported in the journal One Earth today (October 1
“Our findings show that despite technological innovations, including the use of fire and refined stone tools, the formation of complex social networks and – in the case of Neanderthals – even the production of glued spearheads, fitted clothing and a good amount of cultural and genetic exchange with Homo sapiens, past species of Homo could not survive intense climate change, “said Pasquale Raya of the University of Napoli Federico II in Napoli, Italy. “They tried a lot; they made the warmest places within reach as the climate cooled, but at the end of the day it wasn’t enough. “
To shed light on past extinctions of Homo species, including H. habilis, H. ergaster, H. erectus, H. heidelbergensis, H. neanderthalensis and H. sapiens, researchers relied on a high-resolution climate emulator that provides temperature, precipitation and other data over the last 5 million years. They also looked at an extensive fossil database of more than 2,750 archaeological records to model the evolution of the climatic niche of Homo species over time. The aim was to understand the climatic preferences of these early people and how they reacted to climate change.
Their research offers solid evidence that three species of homo – H. erectus, H. heidelbergensis and H. neanderthalensis – lost a significant part of their climatic niche just before they disappeared. They report that this decline coincided with abrupt, adverse changes in the global climate. In the case of the Neanderthals, things probably got worse from competition with H. sapiens.
“We were surprised by the regularity of the effects of climate change,” said Raya. “It was crystal clear to the extinct species and only to them that the climatic conditions were too extreme just before the extinction and only at that particular moment.”
Raya notes that there is uncertainty in paleoclimatic reconstruction, the identification of fossil remains at the species level, and the aging of fossil sites. But, he says, the basic insights are “true to all assumptions.” The findings could serve as a kind of warning to people today, as we face unprecedented climate change, Raya said.
“It is alarming to find that our ancestors, who were no less impressive in terms of mental strength than other species on Earth, could not withstand climate change,” he said. “And we found that just when our own species was cutting the branch we were sitting on, causing climate change. I personally take this as a thunderous warning message. Climate change has made Homo vulnerable and unhappy in the past, and it could just happen again. “
Reference: “Past disappearances of Homo Species Matching with Increased Vulnerability to Climate Change “by Pasquale Raia, Alessandro Mondanaro, Marina Melchionna, Mirko Di Febbraro, Josè AF Diniz-Filho, Thiago F. Rangel, Philip B. Holden, Francesco Carotenuto, Neil R. Edwards, Matheus S Lima-Ribeiro, Antonio Profico, Luigi Marjorano, Sylvia Castiglione, Carmela Serio and Lorenzo Ruc, 15 October 2020, One Earth.
DOI: 10.1016 / j.oneear.2020.09.007
This work was supported by MCTIC / CNPq / FAPEG.