Kimberly Prather, an atmospheric chemist at the University of California, San Diego, who studies how ocean waves disperse virus-laden aerosols, joins host Sarah Crespi to talk about how she became an outspoken advocate for using masks to prevent coronavirus transmission. A related insight she wrote for Science has been downloaded more than 1 million times.

Mikkel Sinding, a postdoctoral fellow at Trinity College Dublin, talks sled dog genes with Sarah. After comparing the genomes of modern dogs, Greenland sled dogs, and an ancient dog jaw bone found on a remote Siberian island where dogs may have pulled sleds some 9500 years ago, they found that modern Greenland dogs—which are still used to pull sleds today—have much in common with this ancient Siberian ancestor. Those similarities include genes related to eating high-fat diets and cold-sensing genes previously identified in woolly mammoths. In this month’s book segment, Kiki Sanford talks with Rutger Bregman about his book, Humankind: A Hopeful History, which outlines a shift in the thinking of many social scientists to a view of humans as more peaceful than warlike.