Humans may have learned kissing 50,000 years ago; new evidence revealed

New Delhi (The Uttam Hindu) – How did kissing, considered a common way of expressing affection, originate in humans? This question has long puzzled scientists. Now, a new study has revealed a surprising insight: humans first learned to kiss from their close relatives, the Neanderthals, about 50,000 years ago.

Kissing was not a natural behavior in the first humans.

According to researchers, the early Homo sapiens present on Earth 50,000 years ago did not know anything like kissing. Neanderthal humans, who lived in Europe and Western Asia at that time, are considered to be the closest ancestors of humans. The study found that kissing was a common social behavior in Neanderthal society, which was later adopted by humans as well.

Researchers from the University of Oxford and the Florida Institute of Technology have found evidence that ancient humans learned to kiss about 50,000 years ago. Neanderthals (Homo neanderthaliensis) were close ancestors of humans who lived in Europe and western Asia from about 400,000 to 40,000 years ago.

Neanderthal DNA is still present in humans today.

Earlier studies have shown that our species, Homo sapiens, had intercourse with Neanderthals. Because Neanderthal DNA is still alive in people today. However, it has not been clear until now whether kissing was a part of their sexual relationships or not. Catherine Talbot, a professor at the Florida Institute of Technology and author of this study, said that kissing may seem like a common or universal behavior, but it is found in only 46 percent of human cultures.

Types of kissing vary widely across societies in terms of social norms, raising the question of whether kissing is an evolved behavior or a cultural invention.

Kissing is an evolutionary puzzle

For modern humans, kissing is generally considered an important part of forming a romantic relationship, but researchers call kissing an evolutionary puzzle because it appears to carry a high risk of disease transmission, while providing no clear reproductive benefits. It's also difficult to trace the evolutionary history of kissing because it's not a clear-cut behavior that can be determined from archaeological remains. For the study, researchers collected data from the scientific literature on modern primate species that have been observed kissing, including chimpanzees, bonobos, and orangutans.

Experts described kissing as non-aggressive, mouth-to-mouth contact that does not involve the exchange of food. They used a statistical approach (called Bayesian modeling) to simulate various evolutionary scenarios along branches of the primate family tree.

The model was run 10 million times to make robust statistical predictions about how our various ancestors engaged in kissing. The results suggest that kissing evolved between 21.5 million and 16.9 million years ago in the ancestors of great apes. There are four living genera of great apes, or Hominidae: orangutans, gorillas, Pan (which includes chimpanzees and bonobos), and Homo, of which only modern humans survive.

The results also showed that Neanderthals engaged in kissing during their relatively recent existence (about 400,000 to 40,000 years ago). This means that Neanderthals, a close relative of modern humans, knew how to kiss several million years ago. This discovery extends previous studies that found that humans and Neanderthals shared microorganisms orally through saliva. This evidence suggests that humans and Neanderthals kissed during intercourse.

Since then, the instinct to kiss has persisted in great ape species, including humans. This also suggests that humans inherited the instinct to kiss from Neanderthals. This instinct still exists in most great apes.

Lice Removal Transformed into Kissing

Last year, evolutionary psychologist Professor Adriano Lameira of the University of Warwick published research outlining the evolutionary origins of human kissing. He said that the act of puckering the lips and lightly sucking was once a technique to remove lice from each other's hair, but later became a natural practice during sexual intercourse.