Even Viruses Can’t Escape Evolution
Evolution, by the very meaning of the word, is generally thought to be a process that slowly unfolds over time, without outside interference.
But now scientists from Rice University are trying to force certain viruses to evolve erratically, in an attempt to kill them. The technique is called “lethal mutagenesis,” and while it may sound vicious, it could be a last resort of self-defense against contagious viruses that attack humans.
Reconstruction of a rotavirus particle. Credit: Graham Colm.Reconstruction of a rotavirus particle. Credit: Graham Colm.Rice bioengineer Michael Deem explains that genetically engineering a virus to mutate in a specific way could change entire sets of the organism’s genes. In their recent study, the Rice scientists develop a formula that can be used to predict exactly how certain mutations alter evolution.
By knowing certain properties of how an organism evolves (for example, its recombination rate, mutation rate, and fitness function), researchers can use the formula to see how making a change will help or hurt the population’s fitness level.
For lethal mutagenesis, an idea that was originally proposed about five years ago, researchers could use the formula to determine how fast to speed up a virus’s mutation rates in order to push it behind a critical threshold, or phase transition.
“If the mutation, recombination or horizontal gene transfer rates are too high, the system delocalizes and gets spread all over sequence space,” Deem explains.
The scientists hope that drug
designers and geneticists will now have a better understanding of how their actions impact evolving populations.