A new study has found a universal genetic code for monogamy in the animal kingdom.
The team of international researchers compared the transcriptomes between monogamous and nonmonogamous species of mice, voles, songbirds, and frogs.
Transcriptomes are the collection of DNA codes that have been transferred into ribonucleic acid (RNA) in a cell. RNA is the molecule responsible for coding and expression of genes from DNA sequences.
The study, published in the journal Proceedings of the National Academy of Sciences, found a difference in 24 genes in monogamous males that were involved in neural development, cognitive function, learning, and memory that appeared to be responsible for their pairing behaviour.
The genetic codes that the monogamous species shared could not be accounted for through evolutionary histories or shared habitats.
Oxytocin, the hormone typically associated with affection, did not appear to be involved in determining monogamy.
However, the study's definition of monogamy didn't extend to sexual exclusivity but was instead assessed as "social monogamy", which is when partners stay together to care for offspring and defend them against danger over their lifespans.
Monogamy is rare in the animal kingdom, occurring in only 5% of animals, and there is very little understanding of why it occurs.
Some of the reasons monogamy may have evolved in certain species include to protect female mates, shared energy expenditure between couples, and increased protection of offspring.
Prairie voles, gray wolves, several penguin species, lar gibbons, black vultures, pot-bellied seahorses, bald eagles, and barn owls are all monogamous.
The research did not extend to human pairing.
