The evolution of sex
A new study has discovered that there may be more to sex than just reproduction, after all, according to LiveScience. Researchers discovered that organisms that have the option of reproducing with or without a partner will generally choose to remain asexual, unless there is a pathogen involved.
If there is a parasite, the organism will choose to breed beyond itself as a way of protecting future generations from the infection. "You actually need these pathogens or parasites to be co-evolving for sex to be maintained," study author Levi Morran, a postdoctoral researcher at Indiana University, told the news provider.
The findings are the first to hint at an answer to a question that has long made researchers scratch their head – why have we evolved to seek out mates? Having two different genders isn't an economic evolutionary solution, particularly when other animals are asexual.
Morran and his colleagues are firm backers of "The Red Queen Hypothesis," named after a character in author Lewis Carroll's book, Through the Looking Glass. In it, the Red Queen tells Alice – the same Alice from her Wonderland adventures – that "it takes all the running you can do to keep in the same place," according to the website.
The scientists have likened this to the constant evolution of sex. Through intercourse, organisms can mix and match genes so that they can develop offspring who are better suited to resisting disease.
By observing certain worms that could mate asexually or sexually, the team found that, once the bugs were exposed to bacteria, their rate of procreating with a partner shot up by 70 percent.
While sex may have evolved long ago to fight the risk presented by parasites, there are now some common STDs that have adapted to our current model of getting down and dirty. That's why it's important to know how to use a condom when knocking boots, because these contraceptives can significantly reduce the risk of infection, according to The Centers for Disease Control and Prevention.