Are females not superior to males? My feminism influenced mother tried to teach me.
The study is flawed in so far as it compares males to hermaphrodites and not females. Nevertheless, the study suggests that females learn faster than males when it comes to dangers.
"In human society, men tend to be seen as risk-takers, while women are seen as being more cautious. According to evolutionary psychologists, this difference developed in the wake of threats to each sex, and their respective needs. ... clearcut differences between females and males are often evident in other animals, even in simple organisms such as worms. In a new study published ... researchers showed that male worms are worse at learning from experience and find it hard to avoid taking risks – even at the cost of their own lives – and that allowing them to mate with members of the opposite sex improves these capabilities. The scientists also discovered a protein, evolutionarily conserved in creatures from worms all the way to humans, that appears to be responsible for the different learning abilities of the two sexes. ...
C. elegans, a tiny roundworm, is a perfect model for investigating the fundamental genetic differences between the sexes, since the sex of the worm is determined by genes alone, without any hormonal or other factors. These worms are divided into two sexes: males, and females that are actually hermaphrodites that also produce male sex cells and can either fertilize themselves or mate with males. ...
Roundworms get their nourishment from bacteria and, unfortunately for them, are particularly attracted to the odor of one disease-causing bacterium that, if they consume it, harms them. ... “training,” growing worms of both sexes separately and feeding them a diet of the harmful bacterium. After this training, the worms were moved to a “test” dish, where they were free to choose between the toxic bacterium and another one that, while less tempting, would not harm them in any way.
The female worms quickly learned to draw a link between the odor of the harmful bacteria and the disease that it causes, and therefore chose to eat from the other bacterium.
Most males, however, failed to learn and continued consuming the harmful bacterium, even though they got just as sick ... When the researchers waited for a longer period, a few of the males eventually learned to avoid the harmful bacterium, but only after they were severely infected, became ill and many of them died. ..."
From the abstract:
"The evolutionary paths taken by each sex within a given species sometimes diverge, resulting in behavioral differences. Given their distinct needs, the mechanism by which each sex learns from a shared experience is still an open question.
Here, we reveal sexual dimorphism in learning: C. elegans males do not learn to avoid the pathogenic bacteria PA14 as efficiently and rapidly as hermaphrodites. Notably, neuronal activity following pathogen exposure was dimorphic: hermaphrodites generate robust representations, while males, in line with their behavior, exhibit contrasting representations.
Transcriptomic and behavioral analysis revealed that the neuropeptide receptor npr-5, an ortholog of the mammalian NPY/NPF-like receptor, regulates male learning by modulating neuronal activity. Furthermore, we show the dependency of the males’ decision-making on their sexual status and demonstrate the role of npr-5 as a modulator of incoming sensory cues. Taken together, these findings illustrate how neuromodulators drive sex-specific behavioral plasticity in response to a shared experience."
Modulation by NPY/NPF-like receptor underlies experience-dependent, sexually dimorphic learning (open access)
Fig. 1: Distinct tissues govern sexually dimorphic short-term learning of PA14 avoidance.
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