Neanderthals and Early Humans Were Likely Kissing, Scientists Propose
From Galápagos albatrosses to Arctic mammals, chimpanzees to great apes, certain species appear to kiss. Currently, researchers propose that ancient hominins did it too – and possibly locked lips with modern humans.
Shared Microbial Clues
This isn't the initial instance experts have proposed Neanderthals and early modern humans were intimately acquainted. In previous studies, scientists have discovered modern people and their Neanderthal relatives shared the same mouth microbe for millions of years after the two species split, implying they exchanged oral fluids.
"Likely they were kissing," she said, adding that the concept chimed with studies that has revealed humans of certain genetic backgrounds contain ancient genetic material in their genetic makeup, revealing genetic mixing was occurring.
Intimate Interpretation
"It certainly puts a different perspective on human-Neanderthal relations," Brindle said.
Writing in the journal Evolution and Human Behavior, the researcher and her team report how, to investigate the evolutionary origins of kissing, they first had to develop a description that was not restricted by how people kiss.
Defining Intimate Contact
"There have been some efforts to define a kiss, but it's largely human-centric, which means that basically non-human species do not engage in this. Currently we understand that they likely engage, it might just not look from what human kissing looks like," said the evolutionary biologist.
Nonetheless, she said some actions that resembled kissing were distinct activities – such as the chewing and food sharing, or "kiss-fighting", seen in fish called French grunts.
Consequently the team came up with a definition of intimate contact centered around social behaviors involving intentional mouth-to-mouth contact with a member of the identical group, with some motion of the oral area but absence of food.
Research Approach
Brindle said they concentrated on reports of kissing in primates from the African continent and Asian regions, including bonobos, apes and great apes, and used digital recordings to verify the observations.
The researchers then integrated this information with details on the evolutionary relationships between extant and ancient types of such primates.
Historical Origins
The team say the results indicate kissing evolved approximately 21.5m and 16.9 million years ago in the predecessors of the large apes.
The position of Neanderthals on this family tree suggests it is probable they, too, engaged in a intimate act, the scientists conclude. But the activity may not have been limited to their specific group.
"The fact that humans engage intimately, the reality that we currently have shown that ancient relatives probably kissed, suggests that the two [species] are also likely to have kissed," Brindle noted.
Evolutionary Importance
While the evolutionary explanation is debated, Brindle said kissing could be employed in reproductive situations to possibly enhance mating outcomes or assist in selecting between partners, while it could assist strengthen connections when practiced in a non-sexual manner.
Another expert in the behavior of great apes commented that as kissing behavior was seen in a wide range of primates it was logical its origins lie deep in our ancient history, and an analysis of various types of kissing among a broader range of animals might extend its origins back even earlier still.
"Things that we consider as characteristics of our species, like intimate contact, are not exclusive to us if we look closely at other animals," the expert noted.
Cultural Aspects
An archaeology expert said that intimate contact had a social component as it was not common to all human groups.
"Nonetheless, as people we succeed or struggle on the quality of our relationships, and ways of encouraging trust and closeness will have been significant for millions of years," she said. "It might be an image that appears a bit contradictory to our misplaced ideas of a rather ruthless and aggressive past, but really it should be expected that Neanderthals – and including Neanderthals and our own species collectively – engaged intimately."
