Prairie voles are social rodents. They live in colonies underground, and display almost human-like behavior. For example, prairie vole couples are known to mate for life, but new research out of UT Austin is calling into question our understanding of the creature, and of evolution itself.
The rodents are often studied because of their ability to form lifelong relationships – known as pair-bonds – which is a rarity among mammals.
But, as it turns out, prairie voles are even more like humans than we thought. Some can be cheaters. While scientists have known their reputation for monogamy was overstated for a while, the difference between monogamous and non-monogomous prairie voles has fueled the work of Steve Phelps, a professor of biology at UT Austin who led the research.
Phelps’ research identifies brain differences between truly monogamous male prairie voles and the cheatin' kind. He discovered that a certain kind of gene – the vasopressin 1a receptor (V1aR) – is more prevalent in the part of the brain dealing with special memory in monogamous voles.
So, a vole that didn’t have a good special memory was more likely to stray.
“They’re more likely to go back to places where they’ve been beat up, that is territories of other males or that they're less likely to keep track of their partners,” Phelps says. “And either of those things could mean that they're more likely to roam around and bump into females from other mates in the process.”
V1aR isn’t the end-all-be-all of monogamy control, but, Phelps hypothesizes, it could be that it works in tandem with hundreds or even thousands of variants to regulate behavior.
He says his findings suggest that both social behaviors – monogamy and sexual promiscuity – are the results of evolution. So, rather than slowly leading a species towards one form of behavior, it could be that the variations are adaptive and that selection is keeping it around.
“So, that is actually the real take-home for me is that it has broader implications for what it means to have a normal brain or be a normal person,” he says.