Genetics of complex diseases: An evolutionary perspective

The advent of the human genome project and the subsequent technological advances in genomic research have provided an unprecedented opportunity, not only to dissect the genetic basis of complex diseases, but has also provided researchers with the means to study the impact of evolution on the genomic architecture of the human genome. In this context, evolution can be defined as a gradual change of genetic information across generations, resulting in an adaptation to the current environmental conditions. From an evolutionary perspective, disease associated mutations should be removed from the population over time. However, recent advances in genomics have shown that various diseases causing mutations have been fixed within the population or are the result of recent adaptations to an ever changing environment. In this review, we provide an overview of the different layers of evolutionary changes affecting the manifestation of disease variants within and between populations. We highlight the impact of evolutionary dynamics as a driving force in the spread of complex diseases and summarize social and cultural effects that may contribute to the different prevalence of common and rare diseases among populations worldwide.