Diseases may rapidly evolve to become more--or less--virulent, according to songbird study
A disease in songbirds has rapidly evolved to become more harmful to its host at least twice in two decades, scientists report.
The research offers a model to help understand how diseases that threaten humans may change in virulence as they become more prevalent in a host population.
"Everybody who's had the flu has probably wondered at some point: 'Why do I feel so bad?'" said Dana Hawley of Virginia Polytechnic Institute, lead author of a paper on the results published today in the journal PLOS Biology.