We study a mutation–selection model with a fluctuating environment. More precisely, individuals in a large population are assumed to have a modifier locus determining the mutation rate u∈0,ϑ at a ...second locus with types v∈0,1. In addition, the environment fluctuates, meaning that individual types change their fitness at some high rate. Fitness only depends on the type of the second locus. We obtain general limit results for the evolution of the allele frequency distribution for rapidly fluctuating environments. As an application, we make use of the resulting Fleming–Viot process and compute the fixation probabilities for higher mutation rates in the special case of two bi-allelic loci in the limit of small fitness differences at the second locus.
Inference of recent admixture using genotype data Pfaffelhuber, Peter; Sester-Huss, Elisabeth; Baumdicker, Franz ...
Forensic science international : genetics,
January 2022, 2022-01-00, 20220101, Volume:
56
Journal Article
Peer reviewed
Open access
The inference of biogeographic ancestry (BGA) has become a focus of forensic genetics. Misinference of BGA can have profound unwanted consequences for investigations and society. We show that recent ...admixture can lead to misclassification and erroneous inference of ancestry proportions, using state of the art analysis tools with (i) simulations, (ii) 1000 genomes project data, and (iii) two individuals analyzed using the ForenSeq DNA Signature Prep Kit. Subsequently, we extend existing tools for estimation of individual ancestry (IA) by allowing for different IA in both parents, leading to estimates of parental individual ancestry (PIA), and a statistical test for recent admixture. Estimation of PIA outperforms IA in most scenarios of recent admixture. Furthermore, additional information about parental ancestry can be acquired with PIA that may guide casework.
•We improve statistical methods for Biogeographical Ancestry inference to account for different admixture of both parents.•The resulting recent admixture model has a higher accuracy in estimating individual admixture in most cases.•We give a likelihood ratio test for recent admixture, which is both highly specific and sensitive for recent admixture.•We find evidence of recent admixture in the 1000 genomes dataset.•The self-report on recent admixture of two self-sequenced samples was only confirmed in one case.
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