Jay Novella

This study in many ways is an attempt to deal with a fossil problem.

How do you learn about the most ancient animals on Earth if their remains almost never fossilized?

This is not fun for people who are looking into this and want to discover what happens.

Like, but there's no fossils that I could find.

All right.

So to put this in context, we need to go back.

way back machine, half a billion years to the time around the time of the famous Cambrian explosion.

So at that time, about 539 million years ago, we see a relatively rapid, very rapid increase in evolutionary diversification in the fossil record.

The Cambrian explosion, from out of nowhere, ostensibly, Steve, ostensibly, we find that ancestors of almost all the modern animals, we find...

almost all modern animal phyla.

And so when I say phyla, you could think complex body plants, anatomical innovations, that's kind of what we're talking about.

So we find the earliest known ancestors of vertebrates, hello, mollusks, sponge, lots of worms, lots of worms, and arthropods, which eventually will become insects, spiders, crabs, and more.

We just found all this great stuff that, wow, I'm sure Steve is champing slash chomping at the bit.

For this next bit here, this explosion isn't just from pure diversification alone.

This is also, it's an artifact.

The reason why we see so many then and not before, it's an artifact of fossilization itself, right?

Precambrian soft bodies hardly never fossilize, right?

They're squishy.

And the newfangled hard body parts in the Cambrian do fossilize.

So that's, so like, so ipso facto, right?