New research suggests humans lived in South America at the same time as now extinct giant sloths, bolstering evidence that people arrived in the Americas earlier than once thought.
Britain’s fertility regulator on Wednesday confirmed the births of the U.K.'s first babies created using an experimental technique combining DNA from three people, an effort to prevent the children from inheriting rare genetic diseases.
Our Medieval ancestors left us with a biological legacy: Genes that may have helped them survive the Black Death make us more susceptible to certain diseases today.
Earth desperately needs people to stop burning coal, the biggest single source of greenhouse gases, to avoid the most catastrophic impacts of climate change. But it is the world’s biggest source of fuel for electric power and so many depend on it for their very lives.