Why Did Neanderthals Mysteriously Disappear From Earth 40,000 Years Ago? Researchers Find Clues

Neanderthals, which are extinct species of archaic humans, lived in Europe and Asia (Eurasia), for more than 3,50,000 years. Anatomically modern humans emerged from Africa around the same time.

Did you know that Neanderthals mysteriously vanished from Earth about 40,000 years ago? For years, researchers have tried to find out the reasons behind their disappearance. Neanderthals, which are extinct species of archaic humans, lived in Europe and Asia, together called Eurasia, for more than 3,50,000 years. Anatomically modern humans (Homo sapiens) emerged from Africa around the same time as the disappearance of Neanderthals, one of the greatest mysteries of human evolution.

Researchers involved in the Horizon-funded SUCCESS project have found some clues to the mysterious disappearance of Neanderthals from Europe, and list them in an article published in Horizon: The EU Research & Innovation Magazine. Horizon Europe is the European Union's key funding programme for research and innovation. The SUCCESS project, which stands for Sustainable Urban Consolidation CentrES for conStruction, aims to improve the efficiency and reduce negative impacts of construction supply chain, and is funded by Horizon Europe.

Possible Reasons Behind Disappearance Of Neanderthals

Climate change, the aggression of Homo sapiens, possible competition for resources, and interbreeding between Neanderthals and Homo sapiens are some of the theories behind the disappearance of Neanderthals. Some human populations alive in Europe and Asia contain about three per cent Neanderthal DNA, the article said. 

What Are Neanderthals?

Neanderthals, the closest extinct human relatives, had some defining features such as a distinctive sloped forehead, large pelvis, large middle part of the face, angled cheek bones, and a huge nose for warming cold, dry air. 

The closest extinct human relatives had bodies that were shorter and stockier than humans, another adaptation to living in cold environments. 

They made and used a diverse set of sophisticated tools, controlled fire, lived in shelters, were skilled hunters of large animals, made and wore clothing, and occasionally made ornamental objects.

Neanderthals are believed to have deliberately buried their death and occasionally marked their graves with offerings such as flowers. 

Neanderthals lived during the middle to late Pleistocene Epoch, about 4,00,000 to 40,000 years ago, mostly in Eurasia. Some fossils of Neanderthals have also been discovered in present-day Belgium and the Mediterranean and southwest Asia. 

However, Neanderthals were not the only hominid or human-like species in existence on Earth during the middle to late Pleistocene Epoch. There were several other archaic human groups such as Homo floresiensis and Denisovans, who walked the planet.

Did Climate Change Kill Neanderthals?

According to the article, Professor Stefano Benazzi from the University of Bologna, Italy, said there were several human species at the time of Neanderthals. Suddenly 40,000 years ago, all but one disappeared, Benazzi said. 

A physical anthropologist leading the SUCCESS project to research the earliest migration of Homo sapiens in Italy, Benazzi said it is important to understand what happened. 

Due to thousands of excavated artefacts and fossils, and several near-complete skeletons, scientists have more knowledge about Neanderthals than any other extinct humans. 

Benazzi, who investigated what happened to Neanderthals in Italy around the time that Homo sapiens arrived out of Africa said Italy has a lot of archaeological sites, and there is a good review of the different cultures falling in the time period of interest. 

According to some scholars, climate change may have been responsible for the extinction of Neanderthals. This may have been true in other places, but was not the case in Italy, Benazzi said. 

The SUCCESS project used minerals collected from ancient stalactites (tapering structures hanging like icicles from the roof of a cave, formed of calcium salts deposited by dripping water) to analyse the pollen from palaeolake (ancient lake) cores. The calcium icicles hanging inside caves are effectively time machines, and researchers can decode what the climate was like when they formed, the article said.

The SUCCESS project used this approach to reconstruct the palaeoclimate (prehistoric climate) between 40,000 to 60,000 years ago. Since there was no data indicating catastrophic climate change in Italy, it is unlikely that climate change killed off the Neanderthals. 

Tool-Making Differences Between Neanderthals And Homo Sapiens

The researchers excavated seven sites once inhabited by Neanderthals, closely examining a period of around 3,000 years when populations of Neanderthals and humans may have coexisted. The team investigated the cultural and tool-making differences between the last Neanderthals and the first Homo sapiens in Italy. 

According to the article, Homo sapiens in Italy used artefacts such as shell ornaments and projectiles like arrowheads. The SUCCESS project unearthed the earliest evidence for mechanically delivered projectile weapons in Europe. 

Was There Weapons Mismatch Between Neanderthals And Homo Sapiens?

Researchers believe that Neanderthals were at a severe disadvantage to their Homo sapiens relatives in terms of weapons technology. However, Homo sapiens and Neanderthals may have never met in Italy.

According to the article, recently discovered remains in southern Europe show that at least one Neanderthal had been alive 44,000 years ago. Meanwhile, the oldest Homo sapiens remains have been dated to 43,000 years ago. Benazzi said it is possible that Neanderthals and Homo sapiens overlapped, but none of the current evidence shows that.

Benazzi said the result the team got in Italy does not mean that the results will be the same elsewhere. 

Fire Sediments May Give Insights Into Why Neanderthals Disappeared

The researchers studied microscopic and molecular charred matter from ancient fire sediments to see what organic material they left behind. Carolina Mallol, a researcher who studied Neanderthal sites such as El Salt and Abric del Pastor in Spain, said the PALEOCHAR project, which she is a part of, was designed to explore how far archaeologists can take the analytical techniques to squeeze molecular information from the organic black layers in the fire. The PALEOCHAR project examines how Neanderthal diet, fire technology, settlement patterns and surrounding vegetation were affected by changing climatic conditions.

When organic matter such as meat or plants is thrown in a fire, the heat dehydrates it, as a result of which the DNA and proteins are destroyed. However, fatty molecules called lipids can survive if the fire does not get hotter than about 350 degrees Celsius, Mallol and her colleagues have shown in their investigations. 

Palaeolipidomics, which is the study of ancient fats, has been used to study lipids in Roman amphorae (tall and ancient Greek or Roman jar or jug with two handles and a narrow neck), Egyptian mummies and prehistoric leaves, the article said. 

According to Mallol, the questions about Neanderthals, such as why they went extinct, are very ambitious. She said those questions require that one first determine who Neanderthals were and obtain a lot of information about how they lived. However, researchers do not have that information yet.

Archeologists and scientists are using each new piece of information to fathom deeper into the mystery of why humans' closest relatives suddenly disappeared while Homo sapiens managed to survive.