ANN ARBOR, MICHIGAN—According to a statement released by the University of Michigan, Alicia Ventresca Miller of the University of Michigan and her colleagues from the Max Planck Institute for the Science of Human History, the University of Mongolia, and the National Museum in Mongolia tracked the Bronze Age consumption of dairy products in the Altai Mountains through the analysis of proteins recovered from human dental calculus. The researchers then compared what they found in the ancient plaque to archaeological evidence for the size of the population, the use of structured cemeteries, and the construction of large monuments. The study identified the consumption of milk from sheep, goats, and cattle in the beginning of the Bronze Age. The dietary changes brought about by keeping these herds then led to population growth. The development of more complex social systems in the region followed at about 1350 B.C., at about the same time that evidence for the earliest consumption of horse milk was detected. Initially, the researchers added, the consumption of horse milk was rare, and may have been limited to rituals. Read the original scholarly article about this research in PLOS ONE. For more on archaeological research in Mongolia, go to "Around the World: Mongolia."