Dr Ann Jones

Because an asexual female will produce a female and a female, she doubles and doubles and doubles.

driving sex extinct.

So the female-only, asexually reproducing population gain is twice the rate of the sexual.

And this is sometimes referred to as the twofold cost of males.

So if the males are so expensive, why do they still exist?

Right, so as long as we sort of keep this discussion in the realms of the ideal, as long as we've got a stable environment and all the food you need and not many challenges, males are not necessary.

Sex is not necessary.

But as soon as you throw in any stresses, the cost of sex becomes like paying an insurance policy for your species.

This is a way to repair your DNA, to outrun your parasites.

You have a population-level adaptability to the environment.

But does it have to be sex, you know, this eggs and sperm, beavers and woodpeckers business, does it have to be that to get genetic variation from generation to generation?

They absolutely conmarried their sex life.

No joy.

Kevin is talking about dalloid rotifers, microscopic organisms found basically everywhere there's fresh water.

They look like tiny little leeches.

And no sex.

But they do have a fair bit of DNA mix-up going on.

So how are they doing it?

Kevin is being coy.

It's not harsh conditions.