Henry Gee

But then we went our separate ways.

Vertebrates have integrated the two.

So they're almost seamlessly joined.

But tunicates have kind of deconstructed themselves.

So the somatic part is the larva and the visceral part is the adult.

And on my desk several years ago appeared a paper, more from Chengjiang, of something called Vitulicolians.

And I looked at these and I thought, goodness me, expletive deleted, these look like Roma somatico visceral animal.

And these Vitulicolians do indeed have a blobby head.

with little gill slits and a kind of circular mouth and a segmented tail.

And these, not universally, are generally seen as somewhere in the ancestry of vertebrates and tunicates together.

And there is another animal called the Amphioxus, which is a swimmy animal with gill slits.

That used to be seen as the closest relative to vertebrates, but now it's been demoted further back because of all sorts of genetic things.

Now, medical scientists loved tunicates because they had a perfect little heart, but only made out of a few cells, so they were excellent for experimenting ideas on the development of the heart.

And the Amphioxus doesn't have one.

And medical scientists said, really, the tunicates should be closer to vertebrates than they are.

But the genetics now reveals that they are.

We are closely related to tunicates.

We have many of the same genes, many of the same processes.

It's just that tunicates have evolved in a strange deconstructing direction and have also cut down on how many cells they've got.

So they don't have actually many cells.