Ken Barnard - 6/13/07

Spiked Genitals Spur Beetle Evolution


The genitals of male beetles are extraordinarily spiny, helping to anchor the males inside females as they attempt to impregnate them. Unfortunately, these spikes damage the females, potentially compromising the entire reproductive mission.


Now scientists have discovered an evolutionary arms race with these beetle genitalia, with female genitals growing tougher the spinier the male genitals are. The speed at which genitals change in this battle of the sexes could help shed light on how new species evolve.


In the new research, evolutionary biologist Göran Arnqvist at Uppsala University in Sweden and his colleagues investigated seven species of beetles. A number of these species have more than 100 spikes on male genitals, while others have none.


Arnqvist and his colleagues found that as male genitals became spikier and more harmful, females evolved tougher genitals to defend themselves.


Scientists are hoping that the new findings can shed some light on how humans have evolved.


“We can now only guess as to how this research correlates to the evolution of man,” Arnqvist said, “For instance, humans may have evolved at a faster rate than beetles, because I can copulate with the spiniest of these creatures and not be harmed.”


Arnqvist was later seen putting lipstick on a beetle he referred to as Stephanie, before continuing his “research,” which consisted of dinner and drinks at a local discothèque.