Kissing May Have Evolved 21.5 Million Years Ago in Ancestor of Nice Apes and Humans

Kissing May Have Evolved 21.5 Million Years Ago

By Stephanie Pappas edited by Jeanna Bryner

For people, kissing holds main cultural cachet, accompanying confessions of romantic love, spiritual rituals of reverence and even betrayals, à la The Godfather Part II’s “kiss of death.”

New analysis means that kissing most likely predates humanity and developed between 16.9 million and 21.5 million years in the past, after the ancestor of the nice apes break up from the lesser apes, or gibbons. There is even proof that Neandertals kissed.

“Kissing is a really interesting one because it’s something humans seem to take for granted,” says research lead writer Matilda Brindle, an evolutionary biologist on the University of Oxford. Surprisingly, romantic kissing has been documented in only 46 percent of human cultures, she says. “But for those who do kiss, it’s this everyday act that also has this huge cultural significance.”

---

On supporting science journalism

If you are having fun with this text, contemplate supporting our award-winning journalism by subscribing. By buying a subscription you’re serving to to make sure the way forward for impactful tales concerning the discoveries and concepts shaping our world immediately.

---

Brindle and her colleagues, Catherine Talbot of the Florida Institute of Technology and Stuart West of Oxford, needed to guage kissing from an evolutionary perspective. So they searched via previous research for contemporary examples of primates smooching, outlined reasonably unromantically as “non-agonistic interaction involving directed, intraspecific, oral-oral contact with some movement of the lips/mouthparts and no food transfer.” They discovered that similar to people, nice apes kiss for a wide range of causes, from conveying sexual want to indicating pleasant, affectionate emotions.

“When chimps have an argument,” she says, “they will often go and literally kiss and make up afterwards.”

The researchers additionally discovered stories of kissing in all nice apes, from people to chimpanzees to orangutans, excluding the jap gorilla. There have been no observations of kissing in gibbons. Based on this taxonomy, the researchers estimate that kissing developed after the nice apes break up from the lesser apes. This signifies that Neandertals and different human ancestors most likely kissed. Bolstering this concept, preliminary proof from DNA in historic dental plaque has proven that Neandertals and humans shared oral bacteria till 112,000 years in the past, hinting that they might have kissed one another.

The primate kissing observations have been too fragmented to disclose a lot about how or why kissing developed, nonetheless. Species that kiss are likely to have mating programs by which females mate with a number of males, the researchers report within the new research, which was printed within the journal Evolution and Human Behavior. Every species that kisses additionally engages in premastication, or chewing meals earlier than giving it over to a different particular person, which might be a precursor to kissing, Brindle says. There is an absence of information about premastication in species that don’t kiss, nonetheless, making the hyperlink tenuous.

It’s additionally unclear whether or not each platonic and sexual kissing have the identical roots, says Zanna Clay, a comparative psychologist at Durham University in England, who researches primate habits however was not concerned within the research. Kissing throughout mating is much less usually noticed within the wild than affectionate kissing, Clay says: “This study is working with a relatively limited dataset.”

Primate researchers haven’t centered a lot on primate kissing, Brindle concurs, saying the paper is a “cry” for researchers to gather extra knowledge. “It’s really exciting that we’ve traced the evolutionary history of kissing back to 21.5 million years ago,” she says, “but we could do so much more if we had additional data.”

It’s Time to Stand Up for Science

If you loved this text, I’d prefer to ask to your assist. Scientific American has served as an advocate for science and business for 180 years, and proper now stands out as the most crucial second in that two-century historical past.

I’ve been a Scientific American subscriber since I used to be 12 years outdated, and it helped form the best way I take a look at the world. SciAm all the time educates and delights me, and conjures up a way of awe for our huge, stunning universe. I hope it does that for you, too.

If you subscribe to Scientific American, you assist make sure that our protection is centered on significant analysis and discovery; that we now have the assets to report on the choices that threaten labs throughout the U.S.; and that we assist each budding and dealing scientists at a time when the worth of science itself too usually goes unrecognized.

In return, you get important information, fascinating podcasts, sensible infographics, can’t-miss newsletters, must-watch movies, difficult video games, and the science world’s finest writing and reporting. You may even present somebody a subscription.

There has by no means been a extra necessary time for us to face up and present why science issues. I hope you’ll assist us in that mission.