MUST WATCH

02:29

Is DNA the key to protecting Earth's tallest species?

Updated 10:37 AM ET, Tue September 4, 2018

Boulder Creek, California (CNN)Coast redwood trees have been on Earth for more than 200 million years, but it only took humans two centuries to cut down 95% of them. Here's how Save the Redwoods League and scientists are working to protect Earth's tallest species.