Today’s evolution piece is going to be short, due to the fact that I put it off until so late in the day. The topic is “drug resistance” — and it is a tragic and very real example of evolution in action. Through the course of a few years, or even less in laboratory conditions, strains of bacteria develop resistance to antibiotic drugs used to treat them. The process whereby fortuitous mutations confer special abilities which improve survival is called “natural selection”. Natural selection is a fundamental principle that explains how evolution occurs. This is a very real danger for modern medicine; one of my favorite celebs, Jim Henson, died from a drug resistant strain of streptococcus.
Drug resistance isn’t the only thing that pathogens evolve to cope with. Our immune system presents another sort of obstacle to their prosperity. Every year (in Asia it seems, for some reason) a new strain of the flu evolves. The new strain is sufficiently different than last year’s that the antibodies you’ve developed are no longer effective. (The flu is actually a virus, but it is able to evolve nonetheless since its genetic principles are the same as real living things.)
So there you have it. If evolution didn’t work, we wouldn’t all be coughing and sneezing (or worse) every January.
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