Premium
A COMPARISON OF THREE INDIRECT METHODS FOR ESTIMATING AVERAGE LEVELS OF GENE FLOW
Author(s) -
Slatkin Montgomery,
Barton Nicholas H.
Publication year - 1989
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.1989.tb02587.x
Subject(s) - biology , statistics , gene flow , population , allele , allele frequency , effective population size , maximum likelihood , selection (genetic algorithm) , population genetics , restricted maximum likelihood , evolutionary biology , mathematics , econometrics , genetic variation , genetics , gene , demography , computer science , artificial intelligence , sociology
Three methods for estimating the average level of gene flow in natural population are discussed and compared. The three methods are F ST , rare alleles, and maximum likelihood. All three methods yield estimates of the combination of parameters (the number of migrants [ Nm ] in a demic model or the neighborhood size [4π Dσ 2 ] in a continuum model) that determines the relative importance of gene flow and genetic drift. We review the theory underlying these methods and derive new analytic results for the expectation of F ST in stepping‐stone and continuum models when small sets of samples are taken. We also compare the effectiveness of the different methods using a variety of simulated data. We found that the F ST and rare‐alleles methods yield comparable estimates under a wide variety of conditions when the population being sampled is demographically stable. They are roughly equally sensitive to selection and to variation in population structure, and they approach their equilibrium values at approximately the same rate. We found that two different maximum‐likelihood methods tend to yield biased estimates when relatively small numbers of locations are sampled but more accurate estimates when larger numbers are sampled. Our conclusion is that, although F ST and rare‐alleles methods are expected to be equally effective in analyzing ideal data, practical problems in estimating the frequencies of rare alleles in electrophoretic studies suggest that F ST is likely to be more useful under realistic conditions.