Sethupathy, PraveenHannenhalli, Sridhar2023-05-222023-05-222008-01-012008-01-16https://repository.upenn.edu/handle/20.500.14332/7765Selectionists and neutralists have fiercely debated, for the past five decades, the extent to which Darwinian selection has shaped molecular evolution. However, both camps do agree that Darwinian selection is a bona fide natural phenomenon. Therefore, various so-called "tests of neutrality" have been developed to detect natural selection on a particular gene or genomic location (for a review on this topic, see Biswas and Akey, 2006). However, these tests are often qualitative and only provide the directionality of selection. A decade and a half ago, S. Sawyer and D. Hartl provided a mathematical framework with which to determine quantitatively the intensity of selection on a particular gene, which they applied to the Adh locus in the Drosophila genome (Sawyer and Hartl, 1992).A Tutorial of the Poisson Random Field Model in Population GeneticsReport