The youngest sex chromosomes on the block, and how to test a Zika vaccine without Zika cases

Strawberries had both male and female parts, like most plants, until several million years ago. This may seem like a long time ago, but it actually means strawberries have some of the youngest sex chromosomes around. What are the advantages of splitting a species into two sexes? Host Sarah Crespi interviews freelance journalist Carol Cruzan Morton about her story on scientists’ journey to understanding the strawberry’s sexual awakening. In 2016, experimental Zika vaccines were swiftly developed in response to the emergence of serious birth defects in the babies of infected woman. Two years after the height of Zika cases, there’s so little spread of the virus in the Americas that it has stymied vaccine trials. Researchers hope to overcome this hurdle with “human challenge experiments”—vaccinating people, then intentionally infecting them with Zika to see whether they’re protected from the virus. Meagan Cantwell talks with staff writer Jon Cohen about his news story that highlights the risks and rewards of human challenge experiments. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. About the Science Podcast [Image: Public domain; Music: Jeffrey Cook] Learn more about your ad choices. Visit megaphone.fm/adchoices