Marshall, today we're talking about parasites. So tell me, what's a parasite?

I had a friend once who was like kind of a parasite like he never like always

slept on people's couches, never did the dishes, like never cooked his own

food. He was living off you without giving anything in return, right? Well, not

me actually that was me. So basically a parasite is an organism that lives off

another organism. I suppose you could call it that. A parasite is a mooch.

A parasite is a mooch. But usually we think about them in terms of you know

tapeworms that live in your intestines and eat your food as you eat it so

you're not getting any of the nutrition or my favorite which is toxoplasma

Gandhi. A parasite that makes mice less afraid of cats. So they're more likely

to be eaten and then they can even get into humans when you're cleaning out

their litter box. And that's the only reason people let cats. The scientists

still out on that. But if all parasites disappeared tomorrow, do you think you

would miss them? No, no, I would not. People might think, oh world without parasites

sign me up. That's Karl Zimmer. My name's Karl Zimmer and I'm a columnist for

the New York Times. Karl's about to tell us why scientists decided to

imagine a world without parasites. It actually wouldn't be a great world

alive in. You might actually miss those mind controlling blood suckers.

I'm Lindsay. And I'm Marshall. Welcome to Tumble, the show where we explore

stories of science discovery. Today on the show we're talking about how

scientists are discovering why the world needs parasites. And not just to

make sure that there are no twinkies in the pantry.

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