Same-Sex Sexual Habits in Primates Might Be an Historic Survival Technique : ScienceAlert

Homosexual behaviour in primates has a deep evolutionary foundation and is extra more likely to happen in species that stay in harsh environments, are hunted by predators, or stay in additional complicated societies, scientists said Monday.

Males or females of the identical intercourse mounting or in any other case stimulating one another have been documented throughout the animal kingdom.

More than 1,500 totally different species have been noticed partaking in same-sex sexual behaviour, with among the earliest studies courting again to the traditional Greek thinker Aristotle.

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But this comparatively widespread behaviour was lengthy dismissed by the scientific neighborhood as a “Darwinian paradox”. This held that gay behaviour in animals goes in opposition to Charles Darwin’s concept of evolution as a result of it doesn’t go down genes by way of replica.

More not too long ago, scientists have proven that this behaviour can partially be inherited from an animal’s mother and father – and might present an evolutionary benefit.

“Diversity of sexual behaviour is very common in nature, among species and in animal societies – it is as important as caring for offspring, fighting off predators or foraging for food,” Imperial College London biologist Vincent Savolainen advised AFP.

Savolainen has been finding out rhesus macaques in Puerto Rico for eight years. His group discovered that male macaques who mount one another kind alliances that would give them entry to extra females – and subsequently finally extra offspring.

In 2023, the group additionally decided that the macaques inherited same-sex behaviour from their mother and father greater than six % of the time – however whether or not this trait was handed down relied on a spread of things.

‘Deep evolutionary root’

For his new research, published in the journal Nature Ecology & Evolution, Savolainen and colleagues collected knowledge on 491 non-human primate species.

They recognized same-sex sexual behaviour in 59 species, together with lemurs, nice apes, and monkeys throughout the Americas, Africa, and Asia.

That the behaviour was so widespread signifies it has a “deep evolutionary root,” the research mentioned.

The researchers then investigated how atmosphere, social organisation, and “life history” traits affected whether or not primates engaged in gay acts.

They discovered that the behaviour was extra widespread in species that lived in harsh environments with restricted entry to meals, resembling barbary macaques.

It was additionally extra widespread in species extra more likely to be hunted by predators – vervet monkeys, for instance, must keep away from all types of huge cats and snakes in Africa.

Stress reliever?

This all means that gay behaviour may assist handle rigidity amongst primate teams during times of stress, the researchers mentioned.

The behaviour was additionally extra widespread amongst species through which men and women are dramatically totally different sizes, resembling mountain gorillas.

These dimension variations typically happen in animals that stay in bigger social teams with intense competitors and stricter social hierarchies. Animals which have men and women of the same dimension are inclined to stay in pairs or smaller household models.

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Same-sex sexual behaviour subsequently “may function as a flexible social strategy, used to reinforce social bonds, manage conflict or build alliances, depending on the ecological and social pressures faced by different species,” the study said.

The researchers theorised that comparable components may have performed a task in human ancestors.

“Our ancestors certainly had to face the same environmental and social complexities,” Savolainen mentioned.

“But there are things that are completely unique to modern humans, who have a complexity of sexual orientation and preference that we do not address at all,” he mentioned.

The research additionally warned in opposition to “misinterpretation or misuse of our findings,” resembling “a misguided notion that social equality might eliminate” same-sex sexual behaviour in fashionable people.

Isabelle Winder, an anthropologist at Bangor University within the UK not concerned within the research, praised the analysis.

“It is their study’s demonstration that modern comparative methods can, for perhaps the first time, realistically illuminate some of the complexities of the evolution of ‘humanlike’ behaviours that I find most exciting,” she commented in Nature.

© Agence France-Presse