Virgin Births: Do we need sex to reproduce?

Sometimes it’s hard to be a woman, as the singer Tammy Wynette famously said. As if doing the reproductive heavy lifting wasn’t bad enough, nature played a cosmic prank in making women need men to complete the task, and giving them a limited window in which to have children.

Perhaps it would be simpler if women could go it alone. After all, not all animals are so hung up on sex. As New Scientist reported earlier this month, virgin births in nature are common. The females of several large and complex animals, such as lizards and sharks, can reproduce without males, a process called parthenogenesis – and now we’re realising it happens in the wild more often than we thought.

So could humans learn this biological trick, allowing women to fall pregnant on their own schedule – without men getting in the way?

It’s a given that, at the very least, women need sperm if they are to conceive. But there’s no reason why that source of sperm ought to be a man. Ten years ago, Japanese researchers unveiled a mouse that had two mothers but no father. Named Kaguya, after a mythical moon princess born in a bamboo stalk, she was created in a laboratory by combining genetic material from two female mice.

With a little bit of help, stem cells from a female donor can be induced to grow into sperm cells – something that would never normally occur. So it might be possible to create a child from two mothers, each of whom contributed half the genetic material. Of course, it’s not quite that simple, as Dr Allan Pacey, a reproductive biologist at the University of Sheffield, explains: “We can make something that looks like a sperm cell down a microscope, but whether it is programmed genetically in the same way is a really difficult thing to establish.

I don’t know if there’s a way to check that except to use the sperm and see if the babies develop normally. You can do that in rats and mice but it’s a big step potentially to do that in a human.”