The Genes for Monogamy
Faithfulness may be written in our genetic code
Some species couple up while others play the field. Wolves, prairie voles, and bald eagles are just a few species in the animal kingdom observed to stay faithful to one partner. Bird species, however, are notorious for having flings. How is it that one species collectively falls into monogamy while others live polygamous lives? Scientists suggest the answer lies in genes.
Curious about how monogamy is evolutionarily selected for, researchers at the University of Texas at Austin conducted a study that investigated what makes monogamous species monogamous. They looked at a range of vertebrates who, over 450 million years, evolved lineages from their common ancestor. To narrow their search, the researchers examined the gene activity of five pairs of species, attempting to identify a pattern shared amongst monogamous animals.
Through their analysis of brain tissue, the researchers identified 24 genes that are closely linked to monogamy in vertebrates. Interestingly, they found the genes involved in neural development, cell-cell signalling, synaptic activity, learning, memory, and cognitive function were more active in monogamous male vertebrates in comparison to polygamous ones. On the other hand, they found the genes involved in gene expression and the regulation of the AMPA receptor (responsible for cell-signalling in the central nervous system) to be less active.
The reproductive behaviour of different species is driven by evolutionary forces that are hard to pinpoint, but this research is a promising start. The researchers have also suggested historical and ecological factors can influence gene expression, which ultimately affects one’s behaviour. It is known amongst the scientific community that one’s genotype (their genetic makeup) and one’s environment are both determinants of their behaviour. So, it is suggested that changing a species’ ecology could cause them to adopt the opposite genetic pattern, making them monogamous or non-monogamous depending on the pattern they possessed before.
Although this study has further developed the field of genetics, it is important to remember the findings of studies conducted on animals rarely translate to humans. Scientists have found treatments for Alzheimer’s Disease and therapies for cancer in mice, but are still in the process of finding cures for these diseases in humans. That being said, animal trial results are pivotal in driving scientific research forward for us. Insulin therapy for human diabetes was developed in the 1800s, when scientists injected pancreas extracts of a variety of species into dogs. Cancer immunotherapy drugs were generated after scientists tested their effectiveness on genetically modified mice. Every medical therapy that has been developed to better human life owes their success to animal experiments (which have gone through vigorous ethical screening beforehand).
If the research does check out for humans however, it would prove itself quite useful for those into polygamy. Next time you’re questioned on why you struggle to commit, you can hold your genetic makeup responsible. Just kidding.