On the relevance of three genetic models for the description of genetic variance in small populations undergoing selection.

摘要

The predictions of genetic variation given by 3 genetic models for small populations undergoing long-term selection were compared. Two were analytical models and the third was a Monte-Carlo simulation model. The first part of the study was concernedwith (1) validation of the predictions provided by a 'full-finite model' for well-known phenomena (e.g. the effect of population management on genetic variation), and (2) an examination of how the assumptions made in the 2 analytical models induce the departure from the third model. The full-finite model was shown to be in close agreement with Gaussian theory when a large number of loci was assumed; the stochastic approach made it much more flexible than 2 algebraic models. In the second part, the infinitesimal model was shown to be more robust than a semi-infinitesimal model. Major sources of discrepancy between the deterministic models and the full-finite model were identified, notably the hypothesis of independence between loci, and the assumptionsof infinite numbers of loci and alleles per locus.