The South Pool of New York's 9/11 Memorial, which honors victims of the attacks. On Wednesday, the Office of the Chief Medical Examiner, announced it identified the remains of Scott Michael Johnson, a 26-year-old securities analyst. Craig Ruttle/AP hide caption
In these two two-cell mouse embryos, the surface of the embryos is outlined in orange, the DNA in the nucleus is indicated in blue and the activity of the LINE-1 gene is indicated via bright red spots. Ramalho-Santos lab/UCSF hide caption
Elation is an Angus bull that recently sold for $800,000. His co-owner, Brian Bell, sells Elation's semen for $50 a sample, about double the going rate. Kristofor Husted/Harvest Public Media hide caption
Joseph James DeAngelo, who authorities suspect is the so-called Golden State Killer responsible for at least a dozen murders, is arraigned in Sacramento, Calif., on Friday. Rich Pedroncelli/AP hide caption
Joseph James DeAngelo, a suspect in a series of killings in California, was arrested Tuesday. Sacramento County, Calif., Sheriff's Office via AP hide caption
Colored transmission electron micrograph of a section through an Escherichia coli bacterium. This rod-shaped bacterium moves via its hair-like flagellae (yellow). Kwangshin Kim/Science Source hide caption
What scientists believe to be our oldest ancestor, the single-celled organism named LUCA, likely lived in extreme conditions where magma met water — in a setting similar to this one from Kilauea Volcano in Hawaii Volcanoes National Park. Danita Delimont/Getty Images/Gallo Images hide caption
Ben and Tara Stern relax at home in Essex, Md. Ben was diagnosed with glioblastoma in 2016. After conventional treatment failed to stop the tumor, Ben tried an experimental drug. Meredith Rizzo/NPR hide caption
The Google Doodle for January 9, 2018 honors Har Gobind Khorana. Google hide caption
Volunteer Greg Ruegsegger is outfitted with monitors, a catheter threaded into a vein and a mask to capture his breath in an experiment run by Joyner to measure human performance. Richard Harris/NPR hide caption
Benjamine Spencer was 22 years old in 1987 when he was arrested for murder. He was newly married, and expecting his first child. Cooper Neill for NPR hide caption
Bacterial cells can now read a synthetic genetic code and use it to assemble proteins containing man-made parts. Gary Bates/Ikon Images/Getty Images hide caption
Martha (right), the last known passenger pigeon, died in 1914. Her preserved body is now on display at the Smithsonian's National Museum of Natural History in Washington, D.C. Susan Walsh/AP hide caption
One of the most famous African dog breeds, the basenji is closely related to street dogs found throughout West Africa. Tara Gregg/EyeEm/Getty Images hide caption
Kathy Niakan, a developmental biologist at the Francis Crick Institute in London, used the CRISPR gene editing technique to find out how a gene affects the growth of human embryos. Courtesy of The Francis Crick Institute hide caption
The first sign of successful in vitro fertilization, after co-injection of a gene-correcting enzyme and sperm from a donor with a genetic mutation known to cause hypertrophic cardiomyopathy. Courtesy of OHSU hide caption
Mitochondrial diseases can be passed from mothers to their children in DNA. JGI/Tom Grill/Getty Images/Blend Images hide caption
