Research into male genitalia is plentiful, with work over the last ten years looking closely at ostrich, chicken, sea slug and a variety of insects having graced the pages of various scientific literatures.
This hot topic is expanding at an exciting rate however one thing is amiss in all of this research and that is how male bias has seemingly excluded research into the female genitalia.
In an attempt to quantify this bias, research into PLoS Biology has taken a look back at the past 25 years of genitalia research, finding a strong bias towards male animals and that this disparity has increased over time. This bias, according to the research team who carried out the research, is due to an ingrained bias in the scientific community that see female genitalia as less important in the course of evolution. This bias the researchers say, is hampering our understanding of evolution and the role genitalia play.
Malin Ah-King, an evolutionary biologist and gender researcher at Humbolt University and colleagues analysed 364 scientific papers published between 1989 and 2013. The team was able to categorise the literature by research question and species studied. The largest group in this sample, 49%, looked at male genitals alone whereas only 8% of papers looked at female genitals alone. Looking at both genitals happened in 44% of the papers studied.
Trying to understand this disparity, the researchers found that it wasn’t limited to research conducted predominantly by male researchers as papers by women also had this gender bias. The cause due to old attitudes towards women and gender was also excluded since this phenomenon seemed to increase post 2000, even after a similar study in 2004 raised these issues.
The authors of the paper are also keen to point out that the notion of female genitalia being less interesting than those of females is false, citing articles in which female genitals were important. These included the genital shields of water strides and the elaborate, corkscrew vagina of the long-tailed duck. “There are a number of studies showing large variation in female genitals, both within and between species. But there’s a lack of knowledge and of studies,” says Ah-King.
What the authors seem to think is the key issue contributing to the bias is the longstanding assumptions about the roles of the sexes in evolution; scientists assumed that the female’s role in sex is passive and relatively unimportant. This dates back to the time of the late, great Charles Darwin, whose theory of sexual selection described females as “coy”, with Darwin’s contemporaries even going to the length of assuming females lacked the mental abilities to choose males.
Thankfully, many of these assumptions have been overturned however there is still an emphasis in evolutionary biology towards the male side of the equation, having the effect of causing a lack of knowledge on the female’s role in reproduction and evolution. Indeed, with just studying the one side, researchers risk examining “just one side of a very complex equation”. An example of this is research on the long, hairy “virga” of he male Euborellia plebeja earwig. An assumption off this structure is that it is good at removing competing males’ sperm but research into the female sex organ show it is longer than the male’s virga, suggesting females have more control over what sperm she keeps.
Elizabeth Pollitzer is director or Portia, a UK based non-profit that seeks to address gender issues in science. She says that male –orientated language such as “wounding the female”, “competitor sperm”, “forced copulation” and “coercive mating” are common in genital research. This further exacerbates this gender bias in science and also helps reinforce societal gender attitudes and stereotypes.