Conditional Gene Genealogies under Strong Purifying Selection
نویسندگان
چکیده
منابع مشابه
Distortions in genealogies due to purifying selection.
Purifying selection can substantially alter patterns of molecular evolution. Its main effect is to reduce overall levels of genetic variation, leading to a reduced effective population size. However, it also distorts genealogies relative to neutral expectations. A structured coalescent method has been used to describe this effect, and forms the basis for numerical methods and simulations. In th...
متن کاملDistortions in genealogies due to purifying selection and recombination.
Purifying selection at many linked sites alters patterns of molecular evolution, reducing overall diversity and distorting the shapes of genealogies. Recombination attenuates these effects; however, purifying selection can significantly distort genealogies even for substantial recombination rates. Here, we show that when selection and/or recombination are sufficiently strong, the genealogy at a...
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An excess of nonsynonymous over synonymous substitution at individual amino acid sites is an important indicator that positive selection has affected the evolution of a protein between the extant sequences under study and their most recent common ancestor. Several methods exist to detect the presence, and sometimes location, of positively selected sites in alignments of protein-coding sequences...
متن کاملThe equivalence between weak and strong purifying selection
Weak purifying selection, acting on many linked mutations, may play a major role in shaping patterns of molecular evolution in natural populations. Yet efforts to infer these effects from DNA sequence data are limited by our incomplete understanding of weak selection on local genomic scales. Here, we demonstrate a natural symmetry between weak and strong selection, in which the effects of many ...
متن کاملStrong Purifying Selection at Synonymous Sites in D. melanogaster
Synonymous sites are generally assumed to be subject to weak selective constraint. For this reason, they are often neglected as a possible source of important functional variation. We use site frequency spectra from deep population sequencing data to show that, contrary to this expectation, 22% of four-fold synonymous (4D) sites in Drosophila melanogaster evolve under very strong selective cons...
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ژورنال
عنوان ژورنال: Molecular Biology and Evolution
سال: 2008
ISSN: 0737-4038,1537-1719
DOI: 10.1093/molbev/msn209