The evolutionary basis of human disease

Natural selection is the driving force behind evolution and describes how traits become fixed in a population due to their tendency to produce reproductive success. An understanding of this process and how it relates to our own species, Homo sapiens, can help us to better understand why many medical conditions occur. Natural selection acts over many generations in order to elicit an effective and stable change in phenotype. In contrast, in the space of just a few generations our environment has changed almost completely. This leads to a mismatch between the internal and external milieu. Evolution is the closest thing to a grand unifying theory in biology, has implications in all areas based in biological science and, as illustrated through this paper, has the potential to inform us about the aetiology of disease and our potential to treat it.