“There are ‘obvious benefits’ of straight-up sex”

Well that should give my daily traffic a bump. The quote is actually referring to the benefits of “straight-up sex” (as opposed to asexual reproduction) for a type of insect — the cottony cushion scale. Via National Geographic, this is fascinating and weird (as is the picture):

An Icerya purchasi beetle and its children.

Are males necessary?

Maybe not for long, at least in an insect species whose females have begun to develop sperm-producing clones of their fathers—inside their bodies.

In the cottony cushion scale—a common agricultural pest that grows to about a fifth of an inch (half a centimeter) long—a new phenomenon has arisen: When some females develop in fertilized eggs, excess sperm grows into tissue within the daughters.

This parasitic tissue, genetically identical to the female’s father, lives inside the female and fertilizes her eggs internally—rendering the female a hermaphrodite and making her father both the grandfather and father of her offspring, genetically speaking.

Though this new form of reproduction hasn’t replaced cottony cushion scale sex, “this parasitic male has taken off like an epidemic in population,” said study leader Andy Gardner, an evolutionary theorist at the University of Oxford.

“Once [this trend] gets started, it’s going to sweep through the population so all the females carry it. So there’s no point for regular males to exist,” Gardner added.

“If you mate with yourself, that doesn’t generate the sort of adaptive variation that regular sex does.”

There are “obvious benefits” of straight-up sex, he said—the offspring get new combinations of genes that can make species overall more robust, he said.