Sex with Men Isn't a Waste of Time, New Study Confirms | Broadly

New research gets to the bottom of why more female animals don't just reproduce on their own.

As many biologists see it, having sex is a waste of our time and energy. While most of us don't view the act as a burden, per se, researchers interested in evolution refer to reproductive sex "as the one of the great paradoxes of biology" because it would be a lot easier if we could just generate offspring asexually.

Indeed, animals put a lot of effort into the way they look and behave to attract a mate. It not only takes energy, but it can also have some bad side effects. "Peacock produce their showy and energetically expensive tails [but] they are also at risk of increased predation," explains Dr. Stuart Auld, a fellow at the University of Stirling, citing a well-known example of this fact. With asexual reproduction, conversely, there's no need for men to tire themselves out. In fact, there's no need for men at all.

Read more:'Sex in the Sea': Dives Into the Wet World of Ocean Orgies and Fish Fetishes

Hypothetically, there would be exponential reproductive boons for women-only populations. "Asexual reproduction should dominate and sex should be rare because sex is enormously wasteful, primarily because males don't produce offspring, (at least not directly)," Auld says. "The amount of new individuals that can be created in a population only depends on the number of females." A new study he conducted this year looks to figure out why biology would favor sex over asexual reproduction, given the former's many pitfalls.

Some species, like female Komodo dragons and a few dozen others, make offspring on their own, but it's not common. Researchers have theorized that the reason why most organisms don't just self-clone is because sex has large-scale advantages, like genetic variation, but up until now, this theory has been difficult to test outside of plant species.

However, Auld and his colleagues devised a way to directly measure the biological benefits of sex using wild-caught waterfleas, an organism that is both sexual and asexual. When he compared how the offspring of a waterflea reacted to exposure to an unfamiliar parasite, he found that sexually produced offspring were twice as resistant to infection.

Through his research, Auld was able to see how genetic variation helps species adapt to new or changing environments, like an evolving parasite population; the waterflea offspring produced asexually were just not able to resist being overtaken by infection. So fortunately for men, I guess, it's important that our offspring don't become sick or diseased.