February 24th, 2015
Episode 162 of 1490 episodes
Newly published research suggests that gerbils not rats, may have been the cause of outbreaks of Black Death across Europe in the 14th Century. Professor Nils Christian Stenseth told the programme that population fluctuations in gerbils in Asia caused fleas to transfer to other mammalian species, including humans, spreading the disease. Researchers were able to deduce gerbil population numbers from the study of tree rings which give information about historic weather patterns. The disease was most likely spread from Asia to Europe along trade routes including the silk road.