The last couple of decades have seen medical science infused with evolutionary reasoning. This has affected such disparate fields as vaccine design and medical genomics. In this post, I will focus on the significance of compensatory mutations and fitness tradeoffs to understanding the evolution of infectious disease.
The imperfection of organisms is often cited as evidence for evolution. This imperfection is obvious from our genomes, which are littered with history – a “genetic book of the dead,” as Richard Dawkins put it. However, even taking the historical explanations of those well-known features into account, organisms are still not ‘perfect,’ and they cannot be. This is because species must compromise, so to speak, when it comes to what traits they will excel in. On the fitness landscape, it is impractical for them to “climb every mountain”. As a result, natural selection leads to specialization as tradeoffs are made between traits. These are known as “fitness tradeoffs.”