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Several close relatives of our species, homo sapiens, have traveled this Earth since the genre Homo evolved over 2 million years ago. These hominids lived in a variety of harsh habitats and environments. Some even crossed paths and crossed paths.
Although several of them have reached important technological and cognitive milestones, such as fire control, the development of stone tools or the creation of clothes, today only us, H. sapiens, to survive.
There has been a lot of debate among academics about our current exclusivity. Some have proposed that H. sapiens“Better technological capabilities may have given us an advantage over others. Others suggested that we ate a more varied diet or were more efficient runners than other hominins.
Meanwhile, other researchers claim that, given the high levels of interbreeding, some hominins may not have become extinct as much as they have fully merged with our gene pool.
The researchers also hypothesized that climate change may have played a role in the extinction of Homo species. In a new study, published in the journal A land, a multidisciplinary team of scientists from Italy, the United Kingdom and Brazil argues that this factor was the main driver of the extinction of other hominids.
The authors believe the findings could serve as a warning as humanity now faces man-made climate change.
“Even the brain powerhouse of the animal kingdom, [the Homo genus], cannot survive climate change when it becomes too extreme, “says paleontologist Pasquale Raia, University of Naples Federico II, one of the study’s authors.” People should care, given the current chaos we are causing. “
For this study, the team focused on just six of the Homo species: H. habilis, H. ergaster, H. erectus, H. heidelbergensis, H. neanderthalensis, and H. sapiens. They omitted others because the fossil record available was too limited for their analysis.
Using a fossil database spanning 2,754 archaeological records, researchers mapped where these species lived over time – linking both fossil evidence and the tools associated with each species at various locations and time periods. time.
They also applied a statistical modeling technique called a past climate emulator that uses available records to reconstruct climatic conditions, including temperature and precipitation, over the past 5 million years.
“This gives a picture of the considerable effects that climatic adversities have had,” says anthropologist Giorgio Manzi.
For three of the five extinct species – H. erectus, H. heidelbergensis, and H. neanderthalensis – a sudden and strong change in climate occurred on the planet just before the disappearance of these species. The climates have become colder for all three, drier for H. heildelbergensis and Neanderthals, and wetter for H. erectus. According to Raia, the temperature change was around 4 to 5 degrees Celsius, on an annual average.
The researchers further assessed how vulnerable these species were to extinction by trying to determine their tolerance to climate change over time, using their presence in various locations as a clue to their preferred niche.
The team determined that before they disappeared, H. erectus and H. heidelbergensis has lost more than half of its niche to climate change. Neanderthals lost about a quarter. Food sources likely declined as habitats changed, and the cold may have threatened the survival of species adapted to warmer climates.
This climatic explanation does not necessarily mean that other extinction factors were not important either – the authors note that competition with H. sapiens, for example, could have made matters worse for Neanderthals – but Raia and colleagues believe their analysis reveals “the main factor” of the past Homo extinctions.
The extinction of the Neanderthals has been studied – and debated – a bit, but the loss of other hominid species has not received attention, says archaeologist Tyler Faith of the University of Utah, who did not participate in the study. This new study represents the first attempt to understand how multiple Homo species have become extinct over vast swathes of space and time, he says.
“But I think it’s a bit early to rule out other potential extinction mechanisms,” Faith adds. He notes that the limited fossil record for some species makes it difficult to get a full picture of environmental or climatic conditions than others. Homo cash could handle.
Likewise, anthropologist Giorgio Manzi, of the Sapienza University in Rome, who did not contribute to the study, notes that many elements must be taken into account to explain the disappearance of the past. Homo species.
The relationship between climate change and extinction is complex, he says, and one does not always lead to the other: “Various abrupt climate failures and environmental crises are known at least over the past million years. . These circumstances did not always lead to extinctions. “
Still, Manzi believes the new work reasonably shows that climate change can have a big impact.
“This offers a picture of the enormous effects that climatic adversities have had on human populations of different species,” says Manzi.
With the planet set to warm to 5 degrees Celsius above pre-industrial levels by 2100, other climate challenges lie ahead.
This work first appeared on SAPIENS under a CC BY-ND 4.0 license. Read the original here.
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