At least that happens in the case of flies. According to research published in the journal Nature , the proximity of related flies during the sexual encounter causes the male to behave less aggressively , and therefore the female is not injured or constantly harassed to copulate. The explanation for this "humanized" behavior lies in the fact that the male sees the transmission of his genes assured and is no longer competitive, which entails a benefit for the species by extending the life of both (up to 30 days, at best). cases) and facilitate reproduction.
To obtain this conclusion, the team of scientists from the University of Oxford (United Kingdom) analyzed the behavior of three groups of virgin males that lived with a single virgin female. One of the groups consisted of three siblings, another of two siblings and one unrelated, and the third of three unrelated males. In the first, the flies were relaxed and the female enjoyed a long reproductive life. In the second, competitiveness increased and the female produced fewer offspring due to harassment, which prevented her from feeding or resting. In the third, the scientists observed a very aggressive courtship that shortened both the male and female lifespan, thereby compromising the overall health of the group .
Although these results are difficult to extrapolate to the human reproductive act, the work highlights the important role of family selection in animal evolution , which encourages us to act altruistically for the benefit of those with whom we share genes.
