2025-10-22
36 分钟How did animals evolve from living in the water to living on land?
Until the turn of the 20th century, this was a mystery.
Paleontologists had fossils of ancient fish dating from the Devonian period about 380 million years ago.
Now these had bones and other features that looked as if they might belong in land animals.
They also had fossils of tetrapods,
a type of creature that lived a few tens of millions of years after those ancient fish.
And these tetrapods were the earliest animals with distinct features for living on land,
things like limbs.
to hold themselves up.
But what was the creature that came between the fish and those tetrapods?
That puzzle was solved in 2004 by a team of scientists hunting for fossils on Ellesmere Island in the Canadian Arctic.
The first view we had of Tectolic Rosia was the front end of the skull.
You could see teeth, you see the front end of the jaw.
That's Neil Shubin, part of that expedition.
And what was exceptional about that first view was it was clearly a flat-headed fish.
And the only thing that could be at the time was a close relative of all the land-living animals.
He's our guest today.
And in an extended conversation, he tells us about his discovery and why,
more than 20 years later, it still resonates for evolutionary biologists.
There's a fish that can do a push-up.