Why do we die? I don't mean to ask this as a philosophical question. I'm not looking for any

existential answers. I'm also not looking for any mechanical answers, like because our heart stops

or because our brain doesn't get enough oxygen, no, neither of those work for me today. I'm asking,

why do we die from an evolutionary perspective?

Think about it.

The whole game is survival of the fittest, right?

You win that game by surviving.

So why isn't survival itself fit?

Why does almost every species on earth have a cell by date?

The whole rationale behind evolutionary biology is that certain traits survive because animals with those traits are more likely to survive and pass them on.

So wouldn't immortality be the ultimate trait?

And wouldn't death be the worst trait ever?

I mean, geez, dying is like a big old delete button on you and your traits.

Why would aging evolve? Why would we become less and less fit over time? Why would death be selected for?

Well, maybe it wasn't, I can hear some of you saying. Maybe death is just a guaranteed part of life

and living forever is impossible and so the argument that evolution ever selected aging or death

is specious. But there's just one problem with that. Immortality is possible and evolution

already selected for it.

Today, a jellyfish is going to force us to grapple with death.

Today, we are going to learn about dying from an animal that doesn't need to.

Today we are going to talk about the immortal jellyfish.

Turotopsis Dorney.

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