In a secret location in the United States, two white wolves are lounging in the grass in a sunny, roughly one-acre enclosure. It’s early spring and a chill wind blows through bare trees nearby. The ...

(CNN) — A species of wolf that died out some 12,500 years ago lives again as the “world’s first successfully de-extincted animal,” according to Dallas-based biotech company Colossal Biosciences.

Colossal Biosciences claims it has revived an extinct species, but scientists outside the company are skeptical. Somewhere in the northern US, drones fly over a 2,000-acre preserve, protected by a ...

Editor’s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, together with the solutions. Rolex’s Perpetual Planet Initiative has ...