Researchers from the University of Texas and Cornell University have discovered that cheating can be passed down genetically in male prairie voles. Their study found that a certain genetic trait linked to poorer spatial memory caused them to be more adventurous than faithful males due to their inability to remember rough encounters with other males, suggesting that the cheating behavior of these prairie voles is due to heritable gene expression.
The team examined the expression of the avpr1a gene in particular, which is known to play a role in spatial memory and can predict sexual fidelity in males. They ran numerous experiments and identified four single nucleotide polymorphisms (SNPs) that influence the expression of avpr1a and found that there were differences in their levels of methylation, which enhances gene expression and thus are heritable.
The study concludes that in areas of high population density, genetic variants that result in poorer spatial memory are favored in order to increase the chances of a male's mating, as opposed to low population densities that favor the opposite, according to the press release.
"We know this brain region that predicts fidelity is critical to memory, but we don't know exactly how those two are related," Steve Phelps, co-author of the study, told Live Science. "My intuition is that there will be a lot of genes related to social behavior that are variable, and that this variation has been maintained by natural selection. It kind of challenges what it means for behavior - or for the brain - to be normal."
The findings were published in the Dec. 11 issue of the journal Science.
