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HOW MUCH HERITABLE VARIATION CAN BE MAINTAINED IN FINITE POPULATIONS BY MUTATION–SELECTION BALANCE?
Author(s) -
Bürger Reinhard,
Wagner Günter P.,
Stettinger Franz
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.tb02624.x
Subject(s) - biology , heritability , natural selection , selection (genetic algorithm) , genetic drift , quantitative genetics , mutation , markov chain , evolutionary biology , trait , stabilizing selection , population , variance (accounting) , neutral mutation , genetics , statistics , genetic variation , mathematics , gene , demography , computer science , accounting , artificial intelligence , sociology , business , programming language
The joint effects of stabilizing selection, mutation, recombination, and random drift on the genetic variability of a polygenic character in a finite population are investigated. A simulation study is performed to test the validity of various analytical predictions on the equilibrium genetic variance. A new formula for the expected equilibrium variance is derived that approximates the observed equilibrium variance very closely for all parameter combinations we have tested. The computer model simulates the continuum‐of‐alleles model of Crow and Kimura. However, it is completely stochastic in the sense that it models evolution as a Markov process and does not use any deterministic evolution equations. The theoretical results are compared with heritability estimates from laboratory and natural populations. Heritabilities ranging from 20% to 50%, as observed even in lab populations under a constant environment, can only be explained by a mutation‐selection balance if the phenotypic character is neutral or the number of genes contributing to the trait is sufficiently high, typically several hundred, or if there are a few highly variable loci that influence quantitative traits.