In both cases, the researchers have evoked scenarios of Cretaceous vicariance, followed by endemic species radiation within Madagascar and subsequent dispersal from Madagascar to other areas.
These conditions prevent bats from performing critical roles in their ecosystems, like helping with pollination and seed dispersal, and consuming pests and insects.
Taken with the rapid overall increase in immigrants in the past decade or so, this dispersal may be one reason why immigration has become so controversial.
Spyrou and her team of disease detectives teamed up with archaeologists, looking for clues to the plague's arrival in Europe and its subsequent pattern of dispersal.
Another fresh hornet queen, found 15 miles southwest of the next nearest find, suggested either a repeated influx from overseas or a vigorous dispersal by the hornets.
He said the study " is a story about us and our history - our goal was to unravel some of the mystery about our evolution and our worldwide dispersal."
What we see today is the product of evolutionary events, resulting from the dispersal of a few human populations out of Africa around 60,000 to 70,000 years ago.
E It was once assumed that improvements in telecommunications would lead to more dispersal in the population as people were no longer forced into cities.