Page URL:

Study suggests 'genetic formula' for monogamy

14 January 2019
Appeared in BioNews 982

Twenty-four genes strongly associated with monogamy in males have been discovered from analysing the genomes of ten animal species. 

The scientists studied the DNA of five pairs of closely related species – four mammals, two birds, two frogs and two fish — comparing monogamous and non-monogamous species. These five pairs represented the five times in vertebrate history that monogamy independently evolved.

'Our study spans 450 million years of evolution, which is how long ago all these species shared a common ancestor,' said Dr Rebecca Young, an author of the study and research associate in University of Texas at Austin's Department of Integrative Biology.

The scientists in this study defined social monogamy as a pair bond for at least one mating season, the sharing of some parental care duties and the joint defense of offspring against predators. This behaviour is not always favoured by evolution.

'Offspring are parasites. They eat you, they take your resources, they make your life more dangerous because it is easier for a predator to find you,' lead author Professor Hans Hofmann at the University of Texas at Austin told the Guardian.

With some difficulty, the international team scoured sites from African lakes to Romanian forests to obtain tissue samples from the brains of three male individuals in all ten species. The researchers performed RNA sequencing, and found that the same 24 changes in gene expression occurred in each monogamous species. The results were unexpected.

'Most people wouldn't expect that across 450 million years, transitions to such complex behaviors would happen the same way every time,' Dr Young said.

There was an exception. One poison dart frog species, Ranitomeya imitator, bucked the genetic trend. This may be linked to the fact that in this species monogamy evolved after males started caring for offspring.

'What evolution came up with is brilliant,' Professor Hofmann told the Guardian. 'When we enter into a pair bond, or have offspring we must take care of, we find it rewarding. The reward system gets hijacked. It says, "Hey, I love this shit."'

The researchers speculate that the same gene pattern may occur in humans. However, the team has not uncovered a causal link or biological mechanism between these genes and monogamy. Future studies could potentially use genome editing in animals to see if it could increase or reduce monogamous behaviours. 

The study was published in the Proceedings of the National Academy of Sciences.

Base paired up: study suggests genetic formula to monogamy
The Guardian |  7 January 2019
Conserved transcriptomic profiles underpin monogamy across vertebrates
PNAS |  7 January 2019
Evolution Used Same Genetic Formula to Turn Animals Monogamous
University of Texas at Austin |  7 January 2019
Monogamy may have a telltale signature of gene activity
Science |  7 January 2019
20 August 2018 - by Dr Loredana Guglielmi 
For their large body size, elephants should get cancer a lot more often than they do – now a new study has found out why...
4 June 2018 - by Ewa Zotow 
Scientists have found a set of genes that may explain the unusually large size of the human brain in comparison with other apes...
29 September 2014 - by Dr Victoria Burchell 
The rise of the single mother may seem a rather modern phenomenon. But even before the first humans walked out of Africa 70,000 years ago, mothers have consistently outnumbered fathers, DNA analysis suggests...
12 June 2005 - by BioNews 
Research on voles could help explain some human behaviour and disorders such as autism, US scientists say. The researchers, based at Emory University in Atlanta, have shown that differences in the length of a piece of 'junk' DNA found in a vole gene affect the animals' behaviour. The study, published...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.