Michael Levin

So, um,

It's no one has, to my knowledge, no one has come up with any convincing discrete step at which my cognitive powers disappear, right?

It just doesn't, the biology doesn't offer any specific step.

It's incredibly smooth and slow and continuous.

And so I think this idea that it just sort of magically shows up at one point and then, you know, humans have true selves that don't exist elsewhere.

I think it runs against everything we know about evolution, everything we know about developmental biology.

These are all slow continua.

And the other really important story I want to tell is where embryos come from.

So think about this for a second.

Amniote embryos, so this is humans, birds, and so on, mammals and birds and so on.

Imagine a flat disk of cells.

So there's maybe 50,000 cells.

And in that, so when you get an egg from a fertilized, let's say you buy a fertilized egg from a farm, right?

That egg will have about 50,000 cells in a flat disk.

It looks like a little tiny little Frisbee.

And in that flat disk, what will happen is there'll be one set of cells will become special, and it will tell all the other cells, I'm going to be the head.

You guys don't be the head.

And so it'll amplify symmetry breaking amplification.

You get one embryo.

There's some neural tissue and some other stuff forms.