Podcast: Why animal personalities matter, killer whale sanctuaries, and the key to making fraternal twins

Online News Editor David Grimm shares stories on a proposal for an orca sanctuary in the sea, the genes behind conceiving fraternal twins, and why CRISPR won’t be fixing the sick anytime soon.   Elizabeth Pennisi joins host Sarah Crespi to discuss bold birds, shy spiders, and the importance of animal personality.   [Image: Judy Gallagher]