Ann Jones

Well throw your assumptions aside because females in the natural world are by no means taking it lying down.

Females have developed a suite of mechanisms and even weapons to ensure that they get some choice in the matter of sex too.

And it's all a little bit more complicated than the alpaca just giving out the wrong number at the club.

Now, there's something like 189 million sperm in a typical human ejaculate, but only a few thousand ever make it to the oviduct.

In birds, less than 2% of wrigglers make it through.

So what's happening to the squiggly boys?

I've got an expert on the line to tell us.

Professor Sarah Robertson is from the University of Adelaide.

Key biological concept alert.

Female cryptic choice is like the metaphorical drawbridge which controls which sperm gets through and which sperm doesn't.

It's called cryptic because it happens at a level that isn't obvious from the outside of the female body.

It's all hidden away and internal.

If we, I actually mean female animals here, if we didn't have this ability to knock out the deadbeat sperm from the competition, then we'd run the risk of using our one precious life bringing up absolute idiots.

So as a female in an evolutionary framework, you want to choose who you mix your genes with, right?

Even if you do that in a cryptic sort of way.

And that has led to some incredible female adaptations.

When I was looking at the penises... You know, a duck penis, the swirly, whirly, tapeworm lookalike penis.

Oh, side note, if you haven't been listening to the previous episodes of this series, you are missing out.

Go to the What The Duck podcast feed right now because this is a journey of discovery, people, and you have just jumped in at third base.

Anyway, back to Paddy.