A Loh Down is a capsule of intriguing scientific research presented clearly, in a witty way, because we believe humor makes knowledge sticky. There is no limit to the science we can present—whether it be in astronomy, biology, computers, evolution, global warming, psychology, politics, sports or beyond—as long as we can make the gist of it graspable in 90 seconds. Our audiences are experts and novices, old and young. Explore the site to customize your journey in your area(s) of interest!

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Religious Fish


Jesus fish, Darwin fish, or both?!? This is Sandra Tsing Loh with the Loh Down on Science, and a new bumper sticker conundrum. Atlantic mollies inhabit a giant cave in southern Mexico. There, these fish have an enemy—the Zoque people. Every spring for hundreds of years, the Zoque have poisoned cave water with the fish-toxic root of the barbasco plant, as part of a religious ritual. The Zoques then ate the dead fish. But over centuries, the fish developed immunities to the poison, and passed their genetic tweak to offspring. Or so say researchers led by an evolutionary ecologist at Oklahoma State and a biologist at Texas A&M. The scientists went to Mexico, scooped up mollies from different parts of the cave and dropped them in a tank with barbasco roots. And... Fish from the previously poisoned waters lived longer, suggesting they inherited resistance from aquatic ancestors. Think natural selection, driven by religion! The fish aren't the only ones changing—the Zoque ceremony was banned in 2007, so the fish are safe from religious folk again. . . Until Friday ... If you know what I mean!


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