HUW CORDEY is the series producer for North America and author of the companion book, North America: A World in One Continent.

What is one fact about North America that amazes you?

It's difficult to stick to one thing, so here are a few.

1. Dogs, camels and horses all evolved in North America — would be hard to imagine human development without these groups of animals.

2. North America is the only continent without an east-west mountain range. This one geological fact has a huge impact on the natural history story of the continent because it means there's nothing to stop the cold air from the arctic mixing with the warm air of the Gulf. It's why 90% of the world’s tornadoes occur in North America; why Florida, which is on the same latitude as Libya, occasionally freezes; and why the continent sees such massive migrations of animals — for example, pretty much every turkey vulture, broad-winged hawk and Swainson's hawk leaves the continent in September/October.

3. The Americas were the last continents to be inhabited by people (leaving aside the unlivable Antarctic of course!)

4. North America was a separate continent until 3 or so million years ago — a blink in the eye in geological time.

BUY THE BOOK: North America: The World In One Continent