JUST A STRAND of Elvis’s hair would do. Pluck out his DNA and it could be copied millions of times using a technique called the polymerase chain reaction (PCR). That was the business plan pitched in the 1990s by Kary Mullis, an American biologist. Mullis had helped develop PCR in the 1980s; in 1993 he shared a Nobel prize.
TopA gigantic landslide shows the limit to how high mountains can grow
IN GEOLOGY, UNLIKE business, nothing is too big to fail. Mountains offer the most spectacular example. Pushed up by the crumpling of Earth’s crust following the collision of tectonic plates, they could in theory keep rising almost indefinitely. In practice, they do not. A suite of geological processes—including the grinding of glaciers, the gentle impact of rain, and forcible cracking by freezing and thawing of water—erode them down to size.
TopChallenging the stigma associated with single mothers in China
AT THE AGE of 29 Gavin Ye decided that she wanted to become a mother, but not a wife. She travelled to America and Russia for in vitro fertilisation (IVF) and gave birth to two daughters. Ms Ye—also known by her Chinese name, Ye Haiyang—now has more than 7.3m followers on Douyin (Chinese TikTok).