Skip to main content
Back to Show
Evolution Earth

The Marine Iguanas' Unusual Shrinking Adaptation

On the Galápagos Islands, Greg Lewbart and his team are trying to catch a marine iguana. Their goal is to study the iguana’s unusual adaptation. They have evolved the ability to shrink and regrow their vertebrae in response to changes in food availability. These conditions arises when the Pacific Ocean that is home to the algae they feed on warms, a result of the weather system known as El Niño.

Support Provided By
Grasslands
Unlock with PBS Passport
55:05
Forgotten and overlooked, grasslands could hold the key to our planet’s survival.
Ice
Unlock with PBS Passport
55:25
Ice
At the planet’s frozen extremes, animals can reveal the changes taking place.
Heat
Unlock with PBS Passport
55:31
In the hottest places, species are going to extraordinary lengths to survive.
Islands
Unlock with PBS Passport
55:26
Remarkable island wildlife reveals insights into our rapidly changing planet.
Earth
Unlock with PBS Passport
55:26
Animals have a surprising story to tell about our rapidly changing planet.
Active loading indicator