Conditional ancestral times and related properties of an extant mutant at a locus A given the number of segregating sites observed at a linked locus B.
It is shown how the mean ancestral times at one locus are affected in a two- locus model with recombination when information is given regarding the number of segregating sites at another locus. For samples of n genes, recursive equations are derived that describe precisely the evolution of the time-depth of such a linked genealogy. Exact numerical solutions and Markov chain Monte Carlo simulations are discussed and compared. The dependence of some properties of a singleton mutation on waiting times between events in the two-locus genealogy is quantified and illustrates the effect of recombination on these properties. The following cases are presented: (1) the distribution of the number of mutant genes in a sample arising from a singleton mutation; (2) the probability that an allele observed in a genes of a sample of size n is the ancestral type (the oldest); (3) the expectation and variance of the age of a mutant having b copies in a sample of n genes.
Slade
Paul F
PF
Department of Mathematics and Statistics, Monash University, Clayton, Victoria 3168, Australia. pslade@umn.edu
D000483:Alleles; D004247:DNA / Q000235:genetics*; D019143:Evolution, Molecular; D008040:Genetic Linkage; D006801:Humans; D008390:Markov Chains; D008957:Models, Genetic; D009010:Monte Carlo Method; D009154:Mutation; D009716:Numerical Analysis, Computer-Assisted; D011995:Recombination, Genetic
D004247:DNA