Scientists Develop Human Embryo Model Without Sperm Or EggsThis week, research published in the journal Nature detailed a model of a 14-day old human embryo created without using sperm or eggs. The hope is to shine a light into a previously unavailable window of an embryo’s development, potentially helping to better understand miscarriages and side effects of medications taken during pregnancy. Ira talks with Casey Crownhart, climate and energy reporter at MIT Technology Review to talk about that and other top science news of the week including Japan’s rocket launch to the moon, zinc batteries, and newly discovered toxic bird species.Sweating Is Our Biological SuperpowerSweat may feel like a constant summer companion, whether or not you exercise frequently. Being damp can feel uncomfortable, but the smells that follow—thanks to the lives and deaths of sweat-munching bacteria—are often socially stigmatized as well. (Deodorant itself is actually a very recent invention!)But sweat isn’t just a cosmetic embarrassment: It’s crucial to keeping us cool, as the evaporating liquid pulls heat energy from our bodies. If you look at animals that don’t sweat, many have evolved alternate adaptations like peeing or even pooping on body parts to achieve that vital evaporative effect. People who are born unable to sweat run a constant risk of heatstroke.Ira talks to Sarah Everts, author of the new book, The Joy Of Sweat, about what makes sweat useful, the cool chemistry of this bodily fluid, and why it’s our evolutionary superpower.Vocal Fry Serves Up Treats For Toothed WhalesToothed whales—species like orcas, bottlenose whales, and dolphins—use echolocation to zero in on prey about a mile deep into the ocean.Until now, scientists couldn’t quite figure out how the whales were making these clicking sounds in the deep ocean, where there’s little oxygen.A new study published in the journal Science, finds the key to underwater echolocation is vocal fry. Although in whales it might not sound like the creaky voice that some people love to hate, the two sounds are generated in a similar way in the vocal folds.Ira talks with the study’s co-author, Dr. Coen Elemans, professor of bioacoustics and animal behavior at the University of Southern Denmark based in Odense, Denmark. To stay updated on all-things-science, sign up for Science Friday's newsletters.Transcripts for each segment will be available the week after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.