Ancient Hominins and Early Humans May Have Engaging in Intimate Contact, Researchers Suggest
From seabirds to Arctic mammals, primates to orangutans, various animals engage in mouth-to-mouth contact. Now, scientists suggest that ancient hominins also engaged in this behavior – and possibly locked lips with early Homo sapiens.
Shared Oral Evidence
It is not the first time experts have proposed ancient relatives and early modern humans were intimately acquainted. Among earlier research, researchers have discovered humans and their Neanderthal relatives possessed the same mouth microbe for millions of years after the two species split, implying they swapped saliva.
"Likely they were kissing," the researcher noted, adding that the concept chimed with research that has found people of non-African ancestry contain Neanderthal DNA in their genetic makeup, revealing interbreeding was at play.
Intimate Spin
"It certainly puts a different spin on human-Neanderthal relations," the lead researcher said.
Publishing in the publication a scientific periodical, the researcher and colleagues detail how, to explore the evolutionary origins of intimate contact, they first had to come up with a description that was not restricted by how humans smooch.
Describing Kissing
"There have been some efforts to describe a kiss, but it's largely focused on humans, which means that essentially non-human species don't kiss. Currently we understand that they probably do, it may appear different from what our intimate contact looks like," said the evolutionary biologist.
However, she said some behaviors that looked like intimate contact were something rather different – such as the chewing and food sharing, or "kiss-fighting", seen in fish known as certain marine animals.
Consequently the team developed a definition of kissing centered around social behaviors involving intentional oral interaction with a member of the identical group, with some movement of the oral area but no transfer of nutrition.
Study Methods
The lead researcher said they concentrated on reports of intimate behavior in non-human species from Africa and Asian regions, including bonobos, apes and orangutans, and employed digital recordings to verify the reports.
The researchers then combined this data with details on the evolutionary relationships between extant and extinct types of such primates.
Evolutionary Origins
The team propose the findings suggest intimate contact developed somewhere between 21.5 million and 16.9m years ago in the predecessors of the great primates.
Placement of ancient hominins on this evolutionary lineage means it is likely they, too, indulged in a kiss, the scientists conclude. But the behavior might not have been confined to their own species.
"Reality that humans kiss, the fact that we now have shown that ancient relatives probably kissed, indicates that the both groups are probably did engage," the researcher noted.
Evolutionary Importance
Although the evolutionary explanation is debated, Brindle explained kissing could be employed in reproductive situations to potentially enhance mating outcomes or assist in selecting between partners, while it might help strengthen connections when practiced in a non-sexual manner.
Another expert in the activities of primates said that as kissing behavior was seen in a wide range of apes it made sense its roots lie deep in our ancient history, and an examination of different forms of intimate behavior among a broader range of species might push its origins back further still.
"Behaviors that we think of as characteristics of human life, like kissing, are not exclusive to us if we examine carefully at different species," the expert noted.
Cultural Elements
An archaeology expert said that kissing had a cultural element as it was not common to all human groups.
"Nonetheless, as humans we thrive or fail on the quality of our relationships, and methods of encouraging confidence and intimacy will have been important for eons," the professor stated. "This could represent an concept that seems a bit contradictory to our incorrect assumptions of a supposedly aggressive and ancient history, but really it should be no surprise that ancient hominins – and even Neanderthals and our human ancestors collectively – engaged intimately."