SEWANEE, TENNESSEE—Science News reports that the weathering of volcanic rock at the site of Easter Island’s major rock quarry enriched the surrounding soil with phosphorus and other elements crucial for the growth of crops. Sarah Sherwood of the University of the South said radiocarbon dating of burned wood and plant material recovered from the quarry’s slopes suggests that the Rapa Nui began to farm there between A.D. 1495 and 1585, when soil quality deteriorated on other parts of the island. Microscopic plant remains in the soils indicate that Rapa Nui farmers grew sweet potatoes, bananas, taro, paper mulberry fruit, and perhaps bottle gourd in the enriched soil. Twenty-one partially buried monolithic statues known as moai have also been found on the quarry’s slopes. Jo Anne Van Tilburg of the University of California, Los Angeles, has investigated the backs of two of these statues and found that they were carved with crescent shapes and other figures before they were placed in pits packed with gravel to hold them upright. She thinks the statues may have been used in ceremonies to encourage crop growth. To read more about the Rapa Nui people's adaptation to Easter Island's harsh conditions, go to "World Roundup: Chile."