How Algae Survived A Mass Extinction Sixty-six million years ago when an asteroid slammed into what is now the Yucatan peninsula, it set off a period of near global darkness for almost two years. Scientists think a majority of land species went extinct during that time, but what was going on in the planet’s oceans? And how were these ecosystems able to bounce back? In a new paper published in Science Advances, researchers say what saved Earth’s oceans may have been a type of algae that could hunt for food. Ira is joined by one of the paper’s authors, Andrew Ridgwell, a professor of earth system science at the University of California, Riverside, to discuss the little algae that could. Gathering Together (Carefully) For A Pandemic Holiday The winter holidays hinge on gatherings of multiple generations of family and friends, indoors, for long periods of time. These are all factors that increase the risk of spreading COVID-19, or unintentionally infecting your loved ones. The CDC now defines a “close contact” as spending 15 minutes within less than 6 feet of an infected person, over the course of 24 hours—encompassing pretty much any holiday gathering. With Thanksgiving looming, new cases are setting records all over the country, and mayors like New York’s Bill de Blasio are urging people not to travel. Many are rightfully now weighing whether they can in good conscience get together. Some epidemiologists, including Anthony Fauci, aren’t outright telling people to cancel their holiday plans, even as they worry about a further surge in the pandemic tied to winter gathering. But if you do choose to travel, there are things you can do to reduce the risk you’re taking, like isolating before you go, getting your flu shot, and taking well-timed COVID-19 tests. Science journalist Kate Baggaley and epidemiologist Julia Marcus discuss how to identify the risks you might encounter, and minimizing those risks you can control—like the choice between driving and flying, how much faith to put in coronavirus testing, and indoor versus outdoor spaces. This Accessible Pregnancy Test Has Results You Can Touch Whatever answer you’re hoping for from a pregnancy test, taking one is rarely a low-stress occurrence. And for many who are blind or vision-impaired, taking a pregnancy test can be even more tricky: the tests use visual displays, and often the only solution for knowing the result is to call a friend, family member, or even stranger into a very private moment. The app Be My Eyes is now partnering with pregnancy test maker ClearBlue to offer volunteer services in reading pregnancy tests—but that still brings a stranger into the process. The UK’s Royal National Institute for the Blind, however, now has a new design for a tactile, accessible test that could be taken privately. It’s colorful, high-contrast, and big enough to use without full sight. And the results appear as bumps that anyone can feel. SciFri producer Christie Taylor talks to Gizmodo reporter Victoria Song, Blind Motherhood blogger Holly Bonner, and Procter & Gamble accessibility leader Sumaira Latif about the value of accessibility in pregnancy testing, and how a good idea might become an actual product. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

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