The remains of a man buried 3,800 years ago in a richly decorated California grave bear some unusual but unmistakable features — a protruding brow, a lantern jaw, thick leg and arm bones, and teeth so crowded together that at one point they erupt in rows three deep. According to a new study of the ancient skeleton, they are signs of acromegaly, a rare disorder of the endocrine system that’s similar to gigantism. The California man is among the very few examples of acromegaly ever found in the archaeological record, and it’s the oldest ever identified, according to Dr. Eric...