The research team used yeast chromosome No. 3 as the model for their biochemical stitchery. Pins and white diamonds in the illustration represent "designer changes" not found in the usual No. 3; yellow stretches represent deletions. Lucy Reading-Ikkanda hide caption

itoggle caption Lucy Reading-Ikkanda

A channel big enough to handle global shipping would require deep dredging throughout Lake Nicaragua, the largest source of fresh water in Central America. Esteban Felix/AP hide caption

itoggle caption Esteban Felix/AP

Until recently, finding characteristic stone and bone tools was the only way to trace the fate of the Clovis people, whose culture appeared in North America about 13,000 years ago. Sarah L. Anzick/Nature hide caption

itoggle caption Sarah L. Anzick/Nature

Clive Hamilton's new book Earthmasters. Courtesy of Yale University Press hide caption

itoggle caption Courtesy of Yale University Press

The Climate Casino by William Nordhaus looks at the economics and politics of global warming. Courtesy of Yale University Press hide caption

itoggle caption Courtesy of Yale University Press

Massive sections of ice (center front) have broken away from the Jakobshavn glacier into the sea. There's enough water stored in Greenland's glaciers to raise the sea level by 20 feet. Ian Joughin/Science/AAAS hide caption

itoggle caption Ian Joughin/Science/AAAS

Love your hair. Artists' depictions of a Neanderthal man and woman at the Neanderthal Museum in Mettmann, Germany. Martin Meissner/AP hide caption

itoggle caption Martin Meissner/AP

Each year, 6 to 8 percent of the global population of sharks and rays gets caught, scientists say. The fish can't reproduce fast enough to keep pace Mike Johnston/Flickr hide caption

itoggle caption Mike Johnston/Flickr

A sperm whale entangled in a drift net. A report says commercial fisheries around the world kill or injure 650,000 mammals a year. Alberto Romero/Marine Photobank hide caption

itoggle caption Alberto Romero/Marine Photobank