Researchers identified an ancient relative of Ebola (and a similar virus called Marburg) dating back 16 to 23 million years.
The research suggests the viruses developed around the same time as the rise of the great apes, the University at Buffalo reported.
"Filoviruses are far more ancient than previously thought," said lead researcher Derek Taylor, a University at Buffalo professor of biological sciences. "These things have been interacting with mammals for a long time, several million years."
The conclusion could help researchers come up with a new vaccine for the deadly diseases. To make their findings the research team looked at viral "fossil genes," which is genetic material acquired after the infection of viruses. They found one fossil gene, called VP35, appeared in the same spot in the genomes of four different rodent species, suggesting it developed during the Miocene Epoch before the rodents evolved into separate species.
"These rodents have billions of base pairs in their genomes, so the odds of a viral gene inserting itself at the same position in different species at different times are very small," Taylor said. "It's likely that the insertion was present in the common ancestor of these rodents."
The first outbreak of Ebola in humans occurred in 1976, but little is known about its history before that. Gaining insight into the ancient origins of the disease could help improve prevention techniques and treatments. The studies could also help determine which species act as undiscovered "reservoirs" for the virus.
"When they first started looking for reservoirs for Ebola, they were crashing through the rainforest, looking at everything -- mammals, insects, other organisms," Taylor said. "The more we know about the evolution of filovirus-host interactions, the more we can learn about who the players might be in the system."
The findings were published in a recent edition of the journal Peer J.
