Bacteria discovered on an ancient flea that was entombed in amber could be an ancestor of the Black Death.
The recent finding from the Dominican Republic may represent the oldest evidence of bubonic plague bacteria, Oregon State University reported. The researchers believe the fossil bacteria is linked to the plague bacteria Yersinia pestis. If this is true, it would mean the bacteria that killed more than half the population of Europe in the 14th century had actually existed for millions of years beforehand, and is even older than the human race.
The bacteria was found attached to the flea's proboscis in a dried droplet and compacted in the rectum. The size and shape of the ancient bacteria is similar to modern forms of Yersinia pestis.
"Aside from physical characteristics of the fossil bacteria that are similar to plague bacteria, their location in the rectum of the flea is known to occur in modern plague bacteria," said George Poinar, Jr., an entomology researcher in the College of Science at Oregon State University, "And in this fossil, the presence of similar bacteria in a dried droplet on the proboscis of the flea is consistent with the method of transmission of plague bacteria by modern fleas."'
The findings contradict modern genomic studies suggesting the "flea-plague-vertebrate cycle" evolved only 20,000 years, as opposed to 20 million.
"If this is an ancient strain of Yersinia, it would be extraordinary," Poinar said. "It would show that plague is actually an ancient disease that no doubt was infecting and possibly causing some extinction of animals long before any humans existed. Plague may have played a larger role in the past than we imagined."
The findings also open up the door for theories suggesting insect-transmitted disease could have played a role in the mass extinction of the dinosaurs. Modern day bubonic plague can infect and kill a variety of animal species, and the same may have happened in ancient times.
The findings were published in a recent edition of the Journal of Medical Entomology.
