Being 'Sexy' is Hereditary

Scientists at the University of Exeter's Cornwall Campus, United Kingdom, showed that "sexy" attractiveness is hereditary. Sexy dads indeed do have sexy sons, at least in the insect world. While it had already been known that specific attractive characteristics are inherited by the offspring, the researchers at the University of Exeter showed that attractiveness is passed on as a whole. This ensures increased probability of successful mating.

The scientists focused in their study on the fruit fly Drosophilae simlans. They noticed randomly paired male and female fruit flies took different lengths of time to mate. The time it took to reach copulation could be anywhere from only two minutes to two hours. Male fruit flies cannot force mating on a female fruitfly. The female fruit fly has to make herself accessible for this purpose. Thus, the time it takes for the female fruit fly to make herself available for copulation indicates the female fruit fly's perception of the attractiveness of the male fruit fly. The less attractive the male fruit fly is, the longer it takes for the female fruit fly to offer herself for copulation.

The male fruit flies were allowed to mate with three different female fruit flies. Then the offspring, too, were paired with single female fruit flies. In this round the scientists again measured the time it took the respective fruit flies to mate. Through this measure the scientists were able to determine that attractiveness, as a whole, is hereditary. The male offspring were as attractive as their fathers to the female fruit flies they were supposed to mate with.

The researchers noted that individual characteristics do not define attractiveness. The female fruit fly is not attracted to just one physical characteristic in a male. In order for the male offspring to be as successful in mating as the father, the father's attractiveness as a whole has to be passed on.

Furthermore, the scientists concluded that passing on the 'sexiness' to the offspring ensures a higher probability of successful mating and therefore the survival of the species. Previous research had already shown that the number of offspring is not determined by the attractiveness of the male to the female.

While the researchers noted that individual characteristics do not define attractiveness, the scientists believe their research can be applied to other species, even humans. The sexiest dads have the most attractive and desirable sons. This is bad news for sons of 'ugly' fathers.

The European Social Fund (ESF) and the Natural Environment Research Council (NERC) provided funding for the research. The study is published in the journal "Current Biology."