The Red Queen Hypothesis

In Lewis Carroll’s ‘Alice’s Adventures in Wonderland’, there occurs a race between Alice and the Red Queen. Like everything else in Wonderland, there’s something unusual about this race! It takes place on the spot. Alice and the Red Queen sprint at the fastest speed that they possibly can, but they don’t seem to get anywhere. This confuses Alice at first, but the Red Queen explains it:

“It takes all the running you can do, to keep in the same place.”

The symbolic meaning of this story led Matt Ridley to name a famous hypothesis in evolutionary biology after it: the Red Queen hypothesis. Simply stated, the Red Queen hypothesis claims that species must evolve at the maximum rate possible just to avoid extinction.

In class on Friday, our microbiology professor provided a fabulous example of the Red Queen hypothesis at work. It has to do with the bacteria Staphylococcus aureus, which is a normal member of the skin flora and is presumably living comfortably on you at this moment! S. aureus can infect wounds, however, and it’s important that we have some effective antibiotics against it.

Penicillin used to work against S. aureus in the 1950’s. Then we used it far too much. Inevitably, the bugs gained widespread immunity, and today penicillin is completely ineffective against S. aureus. So in the 1980’s we began using methicillin instead. Unfortunately (but predictably) this led to the evolution of methicillin-resistant S. aureus (MRSA), which is now a nightmarish perpetrator of hospital-bourne infections. Vancomycin was the next tool in our antibiotic arsenal, but in 2002 we began to see vancomycin resistant S. aureus.

So the race continues between bacteria and antibiotic – both “running” as fast as they can but neither quite getting anywhere.