Scientists have found evidence suggesting that kissing dates back 21 million years, and that great apes, and probably Neanderthals, already engaged in this lip contact, according to research from the University of Oxford published this Wednesday.
The research, led by scientists from the University of Oxford, was published in the journal Evolution and Human Behaviour, the RFI news agency reported.
“This is the first time anyone has adopted a broad evolutionary perspective to examine kissing,” said co-author Matilda Brindle, an evolutionary biologist at the University of Oxford. “Our results add to a growing body of studies that highlight the remarkable diversity of sexual behaviours exhibited by our primate cousins,” Brindle added, according to the Argentine News Agency.
Kissing has long been an evolutionary puzzle for scientists, as it seems to carry high risks, such as disease transmission, without presenting clear reproductive or survival advantages.
Scientists have discovered that Neanderthals, who populated Eurasia coexisting with homo sapiens before disappearing, “probably also had the habit of kissing”. For the purposes of the study, the researchers defined kissing as a “non-aggressive mouth-to-mouth contact that did not involve food transfer”.
The conclusion of the Oxford University scientists is that kissing is “an ancient behavioural trait in great apes”, which appeared in their common ancestor between 16.9 and 21.5 million years ago.
“Kissing has persisted throughout evolution and remains present in most great apes,” the text adds. “By integrating evolutionary biology with data on behaviour, we are in a position to draw informed conclusions about behavioural traits that do not fossilize, such as kissing,” explained Stuart West, co-author and professor of evolutionary biology at Oxford.
The researchers first collected data on modern primates that have been observed kissing, including chimpanzees, bonobos, and orangutans. Treating kissing as a “trait”, the scientists placed it on the primate family tree.
“This discovery, linked to previous studies showing that humans and Neanderthals shared oral microbes (through saliva exchange) and genetic material, strongly suggests that they kissed,” the university emphasises.
