This sequence of images shows the development of embryos formed after eggs were injected with both CRISPR, a gene-editing tool, and sperm from a donor with a genetic mutation known to cause cardiomyopathy. OHSU hide caption

Whitney Houston performs in 1988. The new Showtime documentary, Whitney. "Can I Be Me," includes footage of her world tour in 1999. Bertrand Guay/AFP/Getty Images hide caption

An MS-13 gang member at a prison in Salvador. As the gang spread from Central America to the U.S., authorities say its symbols became more subtle. Luis Romero/AP hide caption

Francine Anderson grew up in a small town in Virginia in the 1950s. She says that when she was 5 years old, she first realized that the color of her skin could put her in danger. Courtesy of StoryCorps hide caption

Liberty University Presidnet Jerry Falwell, Jr., right, praised President Trump for his "bold truthful statement" about Charlottesville. Brendan Smialowski/AFP/Getty Images hide caption

Solar cells sit in the sun at the Desert Sunlight Solar Farm in Desert Center, Calif. The people who run California's electric grid expect the solar power output to be cut roughly in half during the eclipse. Marcus Yam/LA Times via Getty Images hide caption