Magellanic penguins strut their stuff on the rocky shoreline of Argentina's Punta Tombo, home to the largest colony of the birds in the world. Craig Lovell/Corbis hide caption

itoggle caption Craig Lovell/Corbis

A close-up schematic of leaks near the U.S. Capitol shows high leak densities east of the building, but few leaks over the National Mall, where very few natural gas pipelines exist. Robert B. Jackson/Environmental Science and Technology hide caption

itoggle caption Robert B. Jackson/Environmental Science and Technology

Ask not for whom the wolf stalks ... Holly Kuchera/iStockphoto hide caption

itoggle caption Holly Kuchera/iStockphoto

Say aaaaaah! Dental caries and other signs of oral disease are plain to see in the upper teeth of this hunter-gatherer, between 14,000 and 15,000 years old. The findings challenge the idea that the original paleo diet was inherently healthy, says paleo-anthropologist Louise Humphrey. It all depended, she says, on what wild foods were available. Courtesy of Isabelle De Groote hide caption

itoggle caption Courtesy of Isabelle De Groote

Even when a flood obliterates homes, as Superstorm Sandy did in 2012 in the Rockaway neighborhood of Queens, N.Y., the urge to rebuild can be strong. Spencer Platt/Getty Images hide caption

itoggle caption Spencer Platt/Getty Images

In Jiaonan county, the Qi wall incorporates outcrops of bedrock. Linda Nicholas/The Field Museum hide caption

itoggle caption Linda Nicholas/The Field Museum

The Brazilian agricultural sector exported for a value of $94,590 million in 2011. One of its largest exports is soybeans, like these in Cascavel, Parana. Werner Rudhart/DPA /Landov hide caption

itoggle caption Werner Rudhart/DPA /Landov

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

Sediment samples from the seafloor near Long Island. UT Austin Institute for Geophysics hide caption

itoggle caption UT Austin Institute for Geophysics

The EPA tries to keep track of all sorts of methane producers — including herds of methane-belching cattle. Emmett Tullos/Flickr hide caption

itoggle caption Emmett Tullos/Flickr

The wreckage in Tacloban, Philippines, on Nov. 16 was overwhelming, after Typhoon Haiyan plowed through. David P. Gilkey/NPR hide caption

itoggle caption David P. Gilkey/NPR

The beef rib mummy that the researchers tested came from the tomb of Yuya and Tjuiu (sometimes spelled Tuyu). Seen here is a mask of Tjuiu, made out of gilded cartonnage, that was also found in their tomb. Andreas F. Voegelin/AP/Museum Of Antiquities Basel hide caption

itoggle caption Andreas F. Voegelin/AP/Museum Of Antiquities Basel