Scientists solve mystery of why fathers of some species tend to the offspring rather than the mother
We’re not the only ones who love talking about gender roles and gender norms. Reader Dr. Laine Gurley pointed us to an article from yesterday’s Science Daily, which reports on a 20-year study by researchers at the University of Sheffield. “Sex-role reversal has been a formidable puzzle for evolutionary biologists ever since Darwin,” Dr. Andras Liker was quoted.
Aha! So it’s not just a puzzle for 21st Century westernized homo sapiens. Insights, please, into the causes of traditional gender roles, and it can’t be Mad Men. We want causation!
The researchers studied birds where the sex roles were reversed and found there was a higher ratio of males to females in the population, compared with the usual situation where females care for offspring.
Professor Tamás Székely, Professor of Biodiversity at the University of Bath, explained: “Mathematical models suggest that these animals’ behaviour is strongly influenced by their social environment, and our findings support these predictions.
“When there are lots of males in a population, it’s harder to find females, so it benefits males to stay with their mate and look after the young.
“However, the females often take advantage of this and leave the male holding the baby, whilst they go and find another mate.”
Aha! Wait, that’s it? So the biological urge to propagate the species is mere excuse for gigolos or gigolas, in this case, to go out and do their thing? But what does it tell us about ourselves? What can we inference from birds, other than they make for a really clever basis for social media?
Females in the sex role reversed species also take on the traditional male role of being bigger and compete with each other for males.
The role reversal isn’t usually seen in mammals: since males can’t produce milk it’s not as easy for them to take over the parenting completely. However changes in sex role behaviour have been observed in humans when the sex ratio is imbalanced.
This is the nearest thing we’ve seen on avian gender equality. It reflects a lot of what we’ve been witnessing as a culture. Given the chance, either gender can succeed at roles traditionally ascribed to opposite gender. It should be no coincidence that the rise of women in the workplace is on a parallel track with men’s increased domestic roles. It’s a numbers game. Here’s a few more examples of what we’ve been noticing in our own scientificish observations—in the last month.
—photo by Alaskan Dude/Flickr