In 2014, Tuberculosis (TB) surpassed HIV as the leading cause of death from infectious disease. Unlike HIV, TB has long been a scourge of humans; however, exactly how long has been debated.

In this lecture Anne Stone examines the evolutionary history of Mycobacterium tuberculosis, the bacteria that causes TB, focusing on the distribution of TB strains in humans (past and present) in order to understand their relationships, assess patterns of pathogen exchange through time, and investigate how TB adapted to humans and other animals.

Dr. Stone's lab group uses new methods of ancient DNA extraction as well as methods to target pathogen DNA to obtain genetic data from ancient samples with characteristic TB bone lesions. To date, they have sequenced the M. tuberculosis genome from three ancient Peruvians dating to ~1000 years ago. Their analyses indicate that this bacteria likely “jumped” from animals and became a human pathogen within the last 6,000 years. In addition, the results show that ancient Peruvian TB strains are distinct from any known humanadapted TB strains and are most closely related to strains adapted to sea mammals. Sea mammals, specifically Southern Hemisphere seals and sea lions, acquired strains from other animals in Africa and then within the last 2000 years brought these TB strains to South America.

About the speaker:
Anne Stone is Professor in the School of Human Evolution and Social Change at the Arizona State University. Her specialization and main area of interest is anthropological genetics.

Currently, her research focuses on population history and understanding how humans and the great apes have adapted to their environments, including their disease and dietary environments.

Dr. Stone serves on The Leakey Foundation's Scientific Executive Committee.