This TED Talk features microbiologist Kieran Lloyd, recorded live at TED at BCG 2017.

I'm an ocean microbiologist at the University of Tennessee, and I want to tell you guys about some microbes that are so strange and wonderful that they're challenging our assumptions about what life is like on earth.

So I have a question. Please raise your hand if you've ever thought it would be cool to go to

the bottom of the ocean in a submarine. Yes, most of you, because the oceans are so cool.

All right, now, please raise your hand if the reason you raise your hand to go to the bottom of the ocean and the submarine is because it would get you a little bit closer to that exciting mud that's down there.

Nobody. I'm the only one in this room.

Well, I think about this all the time.

I spend most of my waking hours trying to determine

how deep we can go into the earth and still find something, anything, that's alive.

Because we still don't know the answer to this very basic question about life on Earth.

So in the 1980s, a scientist named John Parks in the UK was similarly obsessed,

and he came up with a crazy idea.

He believed that there was a vast, deep, and living, microbial biosphere

underneath all the world's oceans that extends hundreds of meters into the sea floor,

which is cool, but the only problem is that nobody believed him. And the reason

that nobody believed him is that ocean sediments may be the most boring place on Earth. There's no

sunlight, there's no oxygen, and perhaps worst of all, there's no fresh food deliveries for

literally millions of years.

You don't have to have a PhD in biology to know that that is a bad place to go looking for life.

But in 2002, John had convinced enough people that he was on to something

that he actually got an expedition on this drill ship called the Joody's Resolution, and he ran it along

with Bobark of Denmark. And so they were finally able to get some really good pristine deep subsurface

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