Natural Selection in an Outbreak - Issue 41: Selection
▻http://nautil.us/issue/41/selection/natural-selection-in-an-outbreak
Ebola doesn’t select people. We haven’t figured out what Ebola virus selects as its natural host, but it’s definitely not humans. Every once in a while, Ebola stumbles upon a human host, which ends up being a fatal mistake. When I say fatal, I mean for the virus. After all, Ebola is usually not highly efficient at sustaining infection or transmitting from human to human, and eventually that chain of transmission turns into a dead end. Every Ebola outbreak has ended, even the 2014-2015 West African epidemic. When a pathogen jumps from its natural host to an incidental host, it’s called spillover, which probably happens more than we realize. Each outbreak of Ebola started in this manner—Ebola virus slipping from its natural host, moving directly or eventually into a human. According to (...)