The geneticists' work is "immensely impressive," Dr. Little said, and adds a third leg to the studies of plague by historians and by archaeologists.
Until now, studies of plague movements have typically focused on the local development of the infection over time, rather than the social and environmental conditions that allow the bacteria to jump between sometimes far-flung geographical locations.
"It took 50 years to get to the South Dakota line," said Dean E. Biggins, a research biologist with the United States Geological Survey who has studied the effects of plague on ferrets and prairie dogs.
In 1892 he joined the colonial health service and was sent to Hong Kong in 1894, where he and Kitasato Shibasaburo independently discovered the plague bacillus while studying an outbreak of plague in China.
Here, we study the temporal dynamics of plague (Yersinia pestis infection), its vector (flea) and its host (great gerbil) in the PreBalkhash region in Kazakhstan.
This study investigated 3 aspects of plague in its natural hosts in one of the world's major plague foci: the effect of infection on host survival, the dynamics of the antibody response to infection, and the specificity of the NBT test, which has been used as a measure of rodent infection status in previous studies.
This agent had always been the favored cause, but a vigorous minority of biologists and historians have argued the Black Death differed from modern cases of plague studied in India, and therefore must have had a different cause.
It has been the favored cause, but a minority of biologists and historians have vigorously argued that the Black Death differed from modern cases of plague studied in India and therefore must have had a different cause.
"The study of religion has been plagued in many ways by an abundance of ideas and a shortage of strong quantitative tests of these ideas," says human behavior ecologist Richard Sosis of the University of Connecticut, Storrs.
The study of numerosity estimation is plagued by a fundamental problem: if we physically manipulate a collection of items to change its numerosity, then we not only change its numerosity, but inevitably also its physical dimensions.
