THE APPROACH TO HOMOZYGOSITY IN A DIPLOID SELFING SERIES WITH NO MUTATION OR SELECTION,
Abstract
In a diploid selfing series the expected rate of loss of heterozygosity is 50% per generation, provided that mutations and selection do not occur. If the heterozygous loci are randomly distributed over the n chromosome pairs then deviations from this mean rate must be approximately normally distributed and hence essentially dependent only on the cross-over probabilities between pairs of loci. The variance in this case indicates that a large number of linked loci will effectively behave the same as 1.5 nk unlinked loci, where 50 k is the average chromosome length measured in cross-over units. For N independently segregating loci the most probable number of generations required to reach complete homozygosity is approximately log2N, and there is a 50% chance of achieving this state before - log2 (1-2 to the minus 1 over N power) generations have elapsed. The mathematical analysis of this system is facilitated by its representation as a Markov chain. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1964
- Accession Number
- AD0436583
Entities
People
- D. S. Robson