The impact of climate change contributed to the extinction of Neanderthals, the modern human's close relatives, tens of thousands of years ago.
According to a new study, the cold periods in history coincided with the disappearance of Neanderthal populations in different parts of Europe.
Climate Change Drove Neanderthals To Extinction
The extinction of Neanderthals 40,000 years ago remains a big mystery. Some experts hypothesize that they were not reproducing fast enough to keep up with the number of modern humans coming out of Africa. Some think that modern humans slaughtered Neanderthals as they started to move to Europe. Other possible causes include plague that spread and killed entire populations or a volcanic eruption that completely wiped out life in Europe.
However, scientists have proposed a new hypothesis: climate change.
According to the study published in Proceedings of the National Academy of Sciences, about 44,000 years ago, the temperature in Europe started to steadily drop causing cold and dry conditions across the continent. Scientists were able to confirm the changes in the climate by looking at stalagmites, which grow a thin layer every year and alter their chemical composition based on the temperature.
They compared the palaeoclimate data to archaeological records of Neanderthal and found that artifacts nearly disappeared around the time Europe experienced extreme cold temperatures some tens of thousands of years ago.
This implies that climate played a major part in the disappearance of Neanderthals. As soon as the temperature dropped, the population started to die off while modern humans continued to thrive.
"The Neanderthals were the human species closest to ours and lived in Eurasia for some 350,000 years," explained study coauthor Vasile Ersek. "However, around 40,000 years ago — during the last Ice Age and shortly after the arrival of anatomically modern humans in Europe— they became extinct."
The reason why the modern humans were able to survive the cold was because they have a more varied diet. They have started to incorporate fishes and plants into their meals, but the Neanderthals continued to only eat the meat from the animals they hunted. Naturally, animals also become scarce when the weather is cold.
Other Unknown Factors Wiped Out Neanderthals
However, Israel Hershkovitz, a physical anthropologist from Tel Aviv University, thinks that something else killed off Neanderthals.He explained that the modern human's cousins have survived many cold snaps throughout their existence and it does not make sense that the temperature drop 40,000 years ago annihilated the population.
Hershkovitz also questioned whether the stalagmites in the Romanian caves accurately represent the climate across all of Europe.
The researchers argued that modern humans were also affected by the climate change. While Neanderthals went extinct because of the cold, cultures of modern humans also disappeared. However, when the world started to become warmer again, new cultures emerged.