🔗 Share this article

Humans engage in it, monkeys practice it, even polar bears participate in it. And now, researchers have traced the evolutionary origins of kissing.

This research indicates that the mouth-on-mouth kiss developed over 21 million years ago, and was a behavior that the shared predecessor of people and additional great apes likely engaged in.

This research concluded that ancient humans may have kissed as well – and that modern humans and our ancient relatives might have exchanged kisses each other.

By finding proof of other creatures practicing kissing, scientists could construct an "evolutionary lineage" to determine at what time it was probably to have evolved.

To make certain that they were comparing the same behavior across various animal types, the researchers had to give a highly specific – rather unromantic – description to a "kiss".

In this study, released in a academic publication, they defined kissing as non-hostile, directed oral-oral interaction "involving movement of mouthparts or mouthparts and without nourishment exchange".

"Humans, chimpanzees, and bonobos all kiss," stated principal investigator the study's lead author. From that, she determined, "it's probable that their closest common ancestor kissed."

"We think mouth contact likely developed around twenty-one point five thousand-thousand years in the past in the great primates."

During this research, scientists found behavior that fit their research description of kissing in canines, prairie dogs, arctic bears (very sloppy – much tongue), and even seabirds.

The researchers focused on monkeys – and large primates in specific – in an effort to construct an developmental understanding of the beginning of the people's smooch.

The same study also found that Neanderthals – our nearest ancient hominid relatives that became extinct approximately forty thousand years ago – too engaged in kissing.

Earlier piece of research on ancient human DNA also revealed that modern humans and ancient relatives had in common an oral microbe – a type of microorganism found in our mouth fluid.

"That means that they likely been exchanging mouth fluid for hundreds of thousands of years after the two species split," explained Dr Brindle.

While this study identified the time mouth contact developed it was not able to answer the question of why.

Currently exist numerous a number of hypotheses – that it arose from grooming behavior in our ape ancestors or that it might provide an close way to evaluate the health and even the suitability of a partner.

The lead researcher hopes that this will open a door to solving that mystery.

"It's crucial for us to recognize that kissing is something humans possess with our animal relatives," she commented.

"Researchers ought to be investigating this behavior, rather than dismissing it as silly because it has romantic connotations in people."