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An Approximate Bayesian Estimator Suggests Strong, Recurrent Selective Sweeps in Drosophila
- Source :
- Jensen, Jeffrey D; Thornton, Kevin R; & Andolfatto, Peter. (2008). An Approximate Bayesian Estimator Suggests Strong, Recurrent Selective Sweeps in Drosophila. PLoS Genetics, 4(9), e1000198. doi: 10.1371/journal.pgen.1000198. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/00p2x830, PLoS Genetics, Vol 4, Iss 9, p e1000198 (2008), PLoS Genetics
- Publication Year :
- 2008
- Publisher :
- eScholarship, University of California, 2008.
-
Abstract
- The recurrent fixation of newly arising, beneficial mutations in a species reduces levels of linked neutral variability. Models positing frequent weakly beneficial substitutions or, alternatively, rare, strongly selected substitutions predict similar average effects on linked neutral variability, if the product of the rate and strength of selection is held constant. We propose an approximate Bayesian (ABC) polymorphism-based estimator that can be used to distinguish between these models, and apply it to multi-locus data from Drosophila melanogaster. We investigate the extent to which inference about the strength of selection is sensitive to assumptions about the underlying distributions of the rates of substitution and recombination, the strength of selection, heterogeneity in mutation rate, as well as the population's demographic history. We show that assuming fixed values of selection parameters in estimation leads to overestimates of the strength of selection and underestimates of the rate. We estimate parameters for an African population of D. melanogaster (ŝ∼2E−03, ) and compare these to previous estimates. Finally, we show that surveying larger genomic regions is expected to lend much more discriminatory power to the approach. It will thus be of great interest to apply this method to emerging whole-genome polymorphism data sets in many taxa.<br />Author Summary Understanding the process of adaptive evolution requires quantifying the extent to which beneficial mutations contribute to differences between species. However, fundamental parameters of adaptation, such as the rate and strength of beneficial mutations, are poorly understood and have historically been difficult to estimate from data. In particular, distinguishing a high rate of weakly selected substitutions from a low rate of strongly selected substitutions has been problematic. Here, we introduce a new method to estimate the parameters of adaptive evolution from multi-locus population genetic data. We conduct simulations to show that this method is able to discriminate the rare/strong model from the frequent/weak model. Applying this method to an African population sample of Drosophila melanogaster, we estimate selection parameters and find that recurrent adaptive evolution has reduced genome variability by ∼50% on average. The availability of genome-scale population genetic data will lend considerable discriminatory power to the approach. Thus, this new approach represents an important step towards characterizing the nature of adaptive evolution in natural populations.
- Subjects :
- Cancer Research
Mutation rate
lcsh:QH426-470
Genome, Insect
Bayesian probability
Population
Population genetics
statistical tests
Biology
Evolution, Molecular
Bayes' theorem
positive selection
Statistics
Genetics
Medicine and Health Sciences
Animals
Computer Simulation
Selection, Genetic
Evolutionary Biology/Genomics
education
adaptive protein evolution
Molecular Biology
Genetics (clinical)
Ecology, Evolution, Behavior and Systematics
Demography
Statistical hypothesis testing
education.field_of_study
Models, Statistical
Polymorphism, Genetic
Models, Genetic
Evolutionary Biology/Evolutionary and Comparative Genetics
Genetic Variation
Estimator
Life Sciences
Bayes Theorem
hitchhiking
recombination
dna polymorphism data
melanogaster populations
lcsh:Genetics
Fixation (population genetics)
Drosophila melanogaster
Genetics, Population
Evolutionary biology
population-genetics
Africa
genomic rate
linkage disequilibrium
Research Article
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Jensen, Jeffrey D; Thornton, Kevin R; & Andolfatto, Peter. (2008). An Approximate Bayesian Estimator Suggests Strong, Recurrent Selective Sweeps in Drosophila. PLoS Genetics, 4(9), e1000198. doi: 10.1371/journal.pgen.1000198. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/00p2x830, PLoS Genetics, Vol 4, Iss 9, p e1000198 (2008), PLoS Genetics
- Accession number :
- edsair.doi.dedup.....2841312f62227e41792d764b6359a261