Ebola Virus Family is 16 to 23 Million Years Old

Posted on October 27, 2014

Colorized Ebola transmission electron micrograph

A new study has found that Ebola-like viruses have been around for millions of years. Researchers from the University of Buffalo say filoviruses are at least 16 to 23 million years old. The filovirus family includes Ebola and Marburg, another deadly virus that causes lethal hemorrhagic fever.

The researchers say Ebola and Marburg are each members of ancient evolutionary lines. They each shared a common filovirus ancestor millions of years ago.

The recent outbreak in West Africa is unprecedented in modern history with over ten thousand confirmed cases. The World Health Organization (WHO) acknowledges that the actual number of cases may already be three times this amount. Cases have also recently begun to be exported to other countries, such as the United States. This exportation is likely to increase as the cases in Africa swell. The disease is relatively new to us. It was first discovered in the Democratic Republic of Congo in 1976. However, scientists say mammals have been encountering the deadly virus for a very long time.

Derek Taylor, PhD, a University at Buffalo professor of biological sciences, says in a statement, "Filoviruses are far more ancient than previously thought. These things have been interacting with mammals for a long time, several million years."

The clues to the old age of filoviruses were found in what the researchers call "fossil genes." These are described as "chunks of genetic material" that animals acquire when they get infected with a virus. A fossil gene called VP35 was found in the same place in the genomes of two hamster and two vole species. The researchers say the discovery means the material was likely acquired in or before the Miocene Epoch. The researchers say the finding means that the filovirus family is at least as old as the common ancestor of hamsters and voles.

Taylor also says, "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. It's likely that the insertion was present in the common ancestor of these rodents."

The research paper, "Evidence that ebolaviruses and cuevaviruses have been diverging from marburgviruses since the Miocene," can be found here in the journal, PeerJ.

Photo: Frederick A. Murphy/CDC