July/August 2015 Issue

MICRONESIA: Nan Madol, the ruined ancient canal-city, has a lesser known sister site in Leluh off the island of Kosrae. Like Nan Madol, Leluh contains walls and canals of basalt, but it also has tombs partially built with live coral. Scientists dated coral from the tombs to as early as the 1300s, 300 years older than they had been thought to be. Early establishment of the city suggests a long history as a significant political and economic force in the region and rival to Nan Madol. —Samir S. Patel

SRI LANKA: It was thought that humans didn’t begin to live in tropical rain forests and rely on their resources until about 8,000 years ago, in part because the environment can be difficult to navigate and contains fewer accessible food sources than savanna or grasslands. But a new study of isotopic data from human remains dating back 20,000 years shows that until the dawn of agriculture on the island, people actually relied almost exclusively on food from rain forest–related environments rather than open grassland. —Samir S. Patel

ETHIOPIA: A recently discovered fossilized mandible may represent the earliest member of the genus Homo: It dates to around 2.8 million years ago, or 500,000 years earlier than the next oldest known examples. This period in human evolution—the transition from Australopithecus to Homo—is still not well understood ("The First Toolkit," page 12). The bone and teeth have traits that appear to bridge the earlier (rounded chin) and later (slimmer molars) species. It may be a key finding for understanding the origins of our genus. —Samir S. Patel