Scientists Rein In Fears of Ebola, a Virus Whose Mysteries Tend to Invite Speculation

Carl Zimmer in the New York Times:

News that a nurse in full protective gear had become infected with the Ebola virus raised some disturbing questions on Monday. Has the virus evolved into some kind of super-pathogen? Might it mutate into something even more terrifying in the months to come?

Evolutionary biologists who study viruses generally agree on the answers to those two questions: no, and probably not.

The Ebola viruses buffeting West Africa today are not fundamentally different from those in previous outbreaks, they say. And it is highly unlikely that natural selection will give the viruses the ability to spread more easily, particularly by becoming airborne.

“I’ve been dismayed by some of the nonsense speculation out there,” said Edward Holmes, a biologist at the University of Sydney in Australia. “I understand why people get nervous about this, but as scientists we need to be very careful we don’t scaremonger.”

Ebola is a mystery that invites speculation. The virus came to light only in 1976, the first known outbreak. Forty years later, scientists are just starting to answer some of the most important questions about it.

Just last month, for example, Derek J. Taylor, an evolutionary biologist at the University at Buffalo, and his colleagues published evidence that Ebola viruses are profoundly ancient, splitting off from other viral lineages at least 20 million years ago. Dr. Taylor’s research suggests that for most of that time, strains of Ebola infected rodents and other mammals.

In 1976, the virus spilled over into the human population from one of those animals, possibly bats. And every few years since then, a new outbreak has emerged in different parts of Central Africa.

More here.