Steve Brusatte

So the dinosaur DNA is there, buried deep in the genome of modern birds.

and you can make that DNA express itself.

Now, those little birds, something about that tooth mutation is fatal, so you can't actually hatch one.

So there seems to be, over evolutionary time, the teeth were lost, the beak replaced them, and that was really set in genetic stone, but there is still that remnant, that little echo in the genome of birds today.

It seems to be that these birds just had a winning hand of cards.

They could fly really well with those big chest muscles.

They could fly better than the other birds.

They could probably escape more easily.

They grew super fast.

Being able to go from a baby to an adult within a year and make a new generation and so on, that comes in really handy if the world around you is so unstable.

These birds that survived did not live in the trees.

They lived on the ground and waited in shallow water.

This was important because the forests around the world collapsed when the Earth went dark and cold after the asteroid.

There was no sunlight, at least for a few years.

So plants couldn't photosynthesize and they died and they took their entire ecosystems with them.

So if you lived in the trees, your home was gone.

And it's not only that.

If you ate plants, if you ate

animals that ate those things, your entire food was to be gone.

But there was maybe one other ticket out of disaster.