We Homo Sapiens they are just one of six different human species that have populated the world through history. And while evidence abounds as to what caused the demise of our closest relative, the Neanderthals, what caused the other four species to fall remains largely a mystery.
New data suggests these ancient humans may have met a very modern end: climate change.
In a new study published Thursday in the journal One Land, scientists present a new analysis of the fossil record using climate models. They propose a new theory to explain the extinction of these hominids: that the disintegration of the climate niche of ancient humans was a huge driver in their subsequent elimination from Earth.
“They tried hard; they reached the hottest places within reach when the weather got cold, but eventually it wasn̵7;t enough. “
Previous studies of ancient human extinction have largely focused on Neanderthal competition with the former Homo sapiens, but there is relatively little research on what might have spurred the downfall of other older hominids, including H. erectus is H. heidelbergensis.
“[T]The fate of our ancestors is made even more important by the current, ever-increasing pressure that rapid and extreme climate change will continue to place on our species, “the scientists write in the study.
Climate change is a modern problem, but in the ancient Pliocene and Pleistocene – the periods in which these human species roamed – the Earth’s climate also suffered severe changes in temperature. In particular, the last ice age falls precisely between these two eras.
By comparing both the fossil record of these ancient human species with the climate models of the time, the researchers found strong evidence that extreme climate change was linked to the disappearance of these ancient humans, Pasquale Raia, the study’s first author and associate professor at the University of Naples, he said in a statement.
“[D]despite technological innovations including the use of fire and refined stone tools, the formation of complex social networks … the past Homo the species could not survive intense climate change, “Raia said.” They tried; they headed to the warmer places within reach when the weather turned cold, but at the end of the day, it wasn’t enough. “
See also: A fresh look at the disappearance of an ancient human species
The fossil record – To understand what the world might look like for these ancient humans, Raia and her colleagues used a high-resolution climate emulator that can calculate rainfall, temperature and other data for the past five million years. They combined this huge dataset with 2,750 archaeological records. By combining these two different data streams, the researchers were able to reconstruct what a “typical” environment would look like for these ancient humans, as well as the dramatic climate changes that would have been cause for alarm.
Homo erectus, for example, he was at home in the tropical areas of Southeast Asia, so the group was well adapted to warmer climates. The extinction of this species occurred during the last glacial period, which would have created a much climate colder than they evolved to thrive.
“Climate change done Homo vulnerable and unfortunate in the past, and this may just happen again. “
By tracing the overlap between when a specific species went extinct and dramatic climatic events, the researchers saw a clear pattern: extreme changes in climate were closely linked to subsequent extinction.
“We were surprised at the regularity of the effects of climate change,” Raia said. “It was very clear, to the extinct species and to them alone, that the climatic conditions were just too extreme just before extinction and only at that particular time.”
Researchers have also found this out Neanderthals weren’t immune to these effects on the climate. Rather, they suggest that extreme climate, as well as competition with Homo sapiens, could also have led to their extinction.
An ancient warning – While the environments of our ancient relatives were different from our environment now, researchers note that this climatic history serves as a stark warning for our future.
“It is troubling to find that our ancestors, who were no less impressive in mental power than any other species on Earth, could not resist climate change,” Raia said. “Personally I take it as a file thunderous warning message. Climate change done Homo vulnerable and unfortunate in the past, and this may just happen again. “
Abstract: At least six different species of Homo populated the world from the late Pliocene to the Pleistocene. The extinction of all but one is currently shrouded in mystery and no coherent explanation has yet been advanced, despite the enormous importance of the matter. Here, we use a recently implemented past climate emulator and an extensive fossil database comprising 2,754 archaeological records to model the evolution of the climate niche in Homo. We find statistically robust evidence that the three Homo species representing independent terminating lineages, H. erectus, H. heidelbergensis, and H. neanderthalensis, lost a significant portion of their climatic niche space just prior to extinction, without a corresponding reduction in physical scope. This reduction coincides with greater vulnerability to climate change. In the case of Neanderthals, the increased risk of extinction was likely exacerbated by competition with H. sapiens. This study suggests that climate change was the main factor in the extinction of Homo species.