Biologists From Denmark

"1. Both positive and negative selection leave distinctive signatures at the molecular level that can be detected using statistical tests. 2. In population genetic data, selection may affect levels of variability, linkage disequilibrium, haplotype structure and allelic distribution in each nucleotide site (frequency spectrum). In comparative data, selection has a strong effect on the dN/dS ratio. 3. Statistical methods for detecting selection differ in the assumptions they make and how powerful they are. Most methods applicable to population genetic data rely on strong assumptions regarding the demography of the populations, while comparative methods are free of such assumptions. 4. An increasing amount of evidence suggests that positive selection is much more pervasive than previously thought. 5. Inferences regarding selection provide a powerful tool in functional studies, for example for the prediction of possible disease-related genomic regions."