Could other species evolve into humans? w/ Donald Johanson

Donald Johanson: I’m Donald Johanson and I am founding director of the Institute of Human Origins at Arizona State University.

Question: Could other animals evolve into humans?

Johanson: One of the things about being human that we have to look at in perspective of all the life that's existed on this planet for the last several billion years, is that every species is unique. And when a species goes extinct, like the dinosaurs, we've never seen another dinosaur evolve. Ninety-eight, ninety-nine, percent of all species that have lived on the planet that have gone extinct have never reappeared.

So the great tragedy would be if our species Homo sapiens went extinct. It is very unlikely that that scenario would happen again and that humans would re-evolve.

So that it would be a terrible loss -- probably a good thing for the bad things we're doing to the natural world -- but there's no other species that will take over. We have to be a very introspective species. We have to look at ourselves and our responsibilities on this planet and understand that the longevity of our own species is very dependent on how we treat the planet on which we evolved.