National Geographic explorers Mike Libecki and Cory Richards tell us about their trek to a never-before climbed 2,000-foot summit in Antarctica called Bertha's Tower.

Neil Shubin

Rat Empathy, Tiktaalik, Viewer Questions

It turns out that rats might not be such "rats" after all. Our science guy, Neil Shubin, talks about rat empathy and other stories on Scientific Chicago.