Beekeeping is one of the oldest forms of food production. Some of the earliest evidence of beekeeping is from rock painting, dating to around 13,000 BC. It was particularly well developed in Egypt and was discussed by the Roman writers Virgil, Gaius Julius Hyginus, Varro, and Columella. Aspects of the lives of bees and beekeeping are discussed at length by Aristotle. A pioneering beekeeping popularizer in the 19th century United States was Amos Root.