TANZANIA: A case of childhood anemia indicates that early humans relied on meat as part of their diets as many as 1.5 million years ago—and sometimes did not get enough. In fragments of the skull of a two-year-old hominin, researchers found evidence of porotic hyperostosis, a condition associated with nutritional deficiencies related to a lack of meat consumption. The scientists conclude that people must have been hunting at the time, as scavenging would not have yielded enough meat to make it such an essential dietary need. —Samir S. Patel