You've probably heard someone say, "She takes after her father." But what does that really mean? How do we inherit certain traits and characteristics? Writer Carl Zimmer joins us to answer your calls about what heredity means, how it plays out, and whether you should consider taking a DNA test. His book, She Has Her Mother's Laugh is now available in paperback. This episode is sponsored by Turo, KiwiCo (www.kiwico.com/SCIENCERULES), and MagellanTV (www.magellantv.com/sciencerules).