Like father, like son—sexy fathers can give rise to sexy sons in the insect world.
Researchers suggest these findings might also apply to humans.
Males often give showy displays to attract females in the animal kingdom—from cricket songs to peacock plumes. Scientists had long assumed that attractive males can father attractive sons, but hard evidence supporting this idea is actually scant.
To see if attractiveness can be hereditary, researchers in England focused on the fruit fly Drosophila simulans. Males of the species cannot force sex, meaning any mating that happens is because of male charisma.
First, the scientists paired male and female flies at random. They found the length of time it took for them to have sex ranged from two minutes to two hours. The speed at which mating occurred suggests how attractive the males were.
After each male mated with roughly three females, their sons were paired with single females, and the amount of time it took them to score was noted. The investigators found that attractive males indeed sired attractive sons.
"Attractiveness probably can't be defined by individual characteristics, so there is no single physical attribute that female fruit flies are looking for in a mate," said researcher David Hosken, an evolutionary biologist at the University of Exeter in England. "However, there is clearly a benefit to females in having sexy sons that are more likely to attract a mate and produce offspring."
It is possible that attractiveness is hereditable across the animal kingdom, Hosken said.
"It could even be the case in humans that the sexiest dads also have the most desirable sons, which would probably be bad news for my boy," he quipped.
Still, attractiveness may not always prove hereditary in insects and other animals.
"In the closely related standard lab fly, Drosophila melanogaster, there is no sons effect," Hosken told LiveScience. "Extrapolating from one species to another closely related species should be done with caution. Knowing lots about one species may tell you little about another."
Hosken with Michelle Taylor and Nina Wedell detailed their work in the Nov. 20 issue of the journal Current Biology.