Dysfunction, Disease, and the Limits of Selection

Abstract

Paul Griffiths and John Matthewson argue that selected effects play the key role in determining whether a state is pathological. In response, it is argued that a selected effects account faces a number of difficulties in light of modern genomic research. Firstly, a modern history approach to selection is problematic as a basis for assigning function to human traits in light of the small population sizes in the hominin lineage, which imply that selection has played a limited role in shaping these genomes in the evolutionarily recent past. Secondly, determining both the genetic basis of disease and selective histories of the various alleles involved may be experimentally intractable. Thirdly, the existence of “selected disorders” is well supported, and yet on the other hand many other common diseases may not reduce evolutionary fitness. In summary, the biological ends promoted by natural selection, as best modeled in recent research, do not adequately ground a concept of dysfunction that aligns well with the interests of human health.