Peeter Hõrak is Professor in Physiological Ecology of Animals at the University of Tartu.
On average, Estonian women outlive men by 11 years – but why? Sociologists and demographers point to self-destructive behaviours in men, as well as their greater risk of contracting heart disease, but they overlook the underlying causes of these woes.
Since the human lifespan is a result of evolution, providing an explanation for its variability belongs to the domain of natural sciences, more specifically to evolutionary psychology and behavioural ecology. I will try to explain this phenomenon in the discussion which follows.
The theory of sexual selection maintains that the sex that invests more in offspring (almost always the female) cannot reproduce as fast and thus becomes a limited resource to the other sex. This results in a situation in which fertile females are outnumbered by males interested in mating, and therefore, females have an opportunity to be choosy in selecting mates.
Emperor Penguins, Antarctica
At the same time, this situation creates a basis for mating competition amongst males – when there is a shortage of females, each male can increase his reproductive success only at the expense of other males.
Mating competition between males comes in two forms: On the one hand, they have to compete amongst themselves for access to potential mating partners; on the other hand, they need to prove their quality as breeding partners to the opposite sex. Continue reading
