It is a rarity among animals, but monogamy exists in nature and now a scientific study identified the genes related to this trend. Researchers led by Rebecca Young (University of Texas) looked at five pairs of similar species, one monogamous and the other not.
We monogamous They chose California mice, prairie rat rodents, the Alpine bird, the Ranitomeya mimic, and the Xenotilapia fish that lives in Central Africa. We polygamous There were deer mice, Microtus pennsylvanicus rodents, the common bird accent, the frog Oophaga pumilio and an African cichlid fish.
The study published in the journal PNAS explains that there were males and females who were matched at least during the mating season and shared the tasks of feeding offs and defending them, and they continued to be considered monogamous, even if they had occasional chaffing. Among the polygamous, the males tried to spread their sperm as much as possible, but they did not care about their unfoldings.
Although they are so different animals, the analysis of males' brains revealed that the different expression of the same gene series was associated with a polygamous individual or a monogamous individual. The results seem to indicate that monogamy emerged independently many times throughout history, due to the change in expression of the genes that are present in both monogamic and promiscuous.
The authors they found 24 genes whose activity in the brain has a more intense relationship with monogamous behavior. Rebecca Young explains that "we know that some of these 24 genes are related to learning or memory, and it is possible that pairing or caring for children requires a shift in the cognitive processes behind social behavior."
The scientist adds that "an individual has to be able to recognize his partner and find it rewarding to be with him to create a bond." The prairie rat is one of the favorite species to try to understand mammals that are monogamous. Unlike other animals, which avoid the female upon completion of their desire, something happens in your brain which creates a bond that will last forever.
Researcher Larry Young (Emory University) discovered that the secret of this way of life was in the recipients of vasopressin and oxytocin which have the rats in the regions of the brain that regulate the reward. Due to mechanisms similar to those that cause addiction, the brains of these animals associate a pleasurable sensation with the presence of a particular couple.
"It's the first time I see something like this when it comes to social behavior," says Young. The scientist noted that among rats, as among humans, there are people who never mate and others who can not be alone. The researcher created a system to differentiate: single people had a longer version of the gene that produces the vasopressin receptor than the monogamy.