If humans went extinct, could we re-evolve?

If humans went extinct, could we re-evolve?

On a tiny atoll in the Indian Ocean, there lives a flightless bird called the Aldabra rail. It looks unassuming enough — brown feathers, chicken-sized, and incapable of flying. Roughly 136,000 years ago, its ancestors — white-throated rails from Madagascar — flew to Aldabra and found a predator-free paradise; no sharp-toothed prowlers or featherless bipeds with pointy sticks. And so, the rails evolved into flightless versions. Why waste effort a…