Climate change likely drove early human species to extinction, modeling
study suggests

Date:
October 15, 2020
Source:
Cell Press
Summary:
Of the six or more different species of early humans, all
belonging to the genus Homo, only we Homo sapiens have managed
to survive. Now, a study combining climate modeling and the
fossil record in search of clues to what led to all those earlier
extinctions suggests that climate change -- the inability to adapt
to either warming or cooling temperatures - - likely played a
major role in sealing their fate.



FULL STORY ==========================================================================
Of the six or more different species of early humans, all belonging
to the genus Homo, only we Homo sapiens have managed to survive. Now,
a study reported in the journal One Earth on October 15 combining climate modeling and the fossil record in search of clues to what led to all those earlier extinctions of our ancient ancestors suggests that climate change
-- the inability to adapt to either warming or cooling temperatures --
likely played a major role in sealing their fate.


==========================================================================
"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 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," says Pasquale Raia of Universita` di
Napoli Federico II in Napoli, Italy. "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." To shed light on past extinctions of Homo species including H. habilis, H.

ergaster, H. erectus, H. heidelbergensis, H. neanderthalensis, and
H. sapiens, the researchers relied on a high-resolution past climate
emulator, which provides temperature, rainfall, and other data over the
last 5 million years.

They also looked to an extensive fossil database spanning more than 2,750 archaeological records to model the evolution of Homo species' climatic
niche over time. The goal was to understand the climate preferences of
those early humans and how they reacted to changes in climate.

Their studies offer robust evidence that three Homo species --
H. erectus, H.

heidelbergensis, and H. neanderthalensis -- lost a significant portion
of their climatic niche just before going extinct. They report that
this reduction coincided with sharp, unfavorable changes in the global
climate. In the case of Neanderthals, things were likely made even worse
by competition with H.

sapiens.

"We were surprised by the regularity of the effect of climate change,"
Raia says. "It was crystal clear, for the extinct species and for
them only, that climatic conditions were just too extreme just before extinction and only in that particular moment." Raia notes that there is uncertainty in paleoclimatic reconstruction, the identification of fossil remains at the level of species, and the aging of fossil sites. But, he
says, the main insights "hold true under all assumptions." The findings
may serve as a kind of warning to humans today as we face unprecedented
changes in the climate, Raia says.

"It is worrisome to discover that our ancestors, which were no less
impressive in terms of mental power as compared to any other species on
Earth, could not resist climate change," he said. "And we found that
just when our own species is sawing the branch we're sitting on by
causing climate change. I personally take this as a thunderous warning
message. Climate change made Homo vulnerable and hapless in the past,
and this may just be happening again."

========================================================================== Story Source: Materials provided by Cell_Press. Note: Content may be
edited for style and length.


========================================================================== Journal Reference:
1. Pasquale Raia, Alessandro Mondanaro, Marina Melchionna, Mirko Di
Febbraro, Jose` A.F. Diniz-Filho, Thiago F. Rangel, Philip
B. Holden, Francesco Carotenuto, Neil R. Edwards, Matheus
S. Lima-Ribeiro, Antonio Profico, Luigi Maiorano, Silvia
Castiglione, Carmela Serio, Lorenzo Rook.

Past Extinctions of Homo Species Coincided with Increased
Vulnerability to Climatic Change. One Earth, 2020; DOI:
10.1016/j.oneear.2020.09.007 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201015111729.htm

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