Jennifer Doudna and her colleagues found an enzyme in bacteria that makes editing DNA in animal cells much easier. Cailey Cotner/UC Berkeley hide caption

itoggle caption Cailey Cotner/UC Berkeley

A technician tests samples from Ebola-infected patients at a field lab, run by Doctors Without Borders, in Kailahun, Sierra Leone. Tommy Trenchard for NPR hide caption

itoggle caption Tommy Trenchard for NPR

Being able to insert the two man-made letters into DNA, alongside the usual four-letter alphabet, could teach old cells new tricks and lead to better drugs, researchers say. courtesy of Synthorx hide caption

itoggle caption courtesy of Synthorx

Mary-Claire King says obscurity gave her the freedom to spend years looking for breast cancer genes. Mary Levin/University of Washington hide caption

itoggle caption Mary Levin/University of Washington

Up till now, all babies have had two genetic parents. That could soon change. Klöpper & Eisenschmidt GbR/iStockphoto hide caption

itoggle caption Klöpper & Eisenschmidt GbR/iStockphoto

Research excavations like these in Siberia's Denisova Cave are yielding clues to the mating choices of early hominids. Bence Viola/Nature hide caption

itoggle caption Bence Viola/Nature

This micrograph shows a single mitochondrion (yellow), one of many little energy factories inside a cell. Keith R. Porter/Science Source hide caption

itoggle caption Keith R. Porter/Science Source

Does a glass or two of wine during pregnancy really increase the child's health risks? Epigenetics may help scientists figure that out. Katherine Streeter for NPR hide caption

itoggle caption Katherine Streeter for NPR

Red blood cells are normally shaped like doughnuts, but sickle cells (purple) are flattened and clump together. NIH hide caption

itoggle caption NIH

Bates experienced migraines as a child. She made this painting to depict how they felt to her. Courtesy of Emily Bates hide caption

itoggle caption Courtesy of Emily Bates

A microscopic image of prostate cancer. Researchers have found new genetic markers that flag a person's susceptibility to the disease, as well as breast and ovarian cancer. Otis Brawley /National Cancer Institute hide caption

itoggle caption Otis Brawley /National Cancer Institute

A zygote begins its journey to expression in the form of a human being. Science Picture Co./Science Faction/Getty Images hide caption

itoggle caption Science Picture Co./Science Faction/Getty Images