The inbreeding effective population number in dioecious populations

Area of Science:

• Population Genetics
• Quantitative Genetics

Background:

• The inbreeding effective population number is crucial for understanding genetic drift and diversity in populations.
• Dioecious populations with discrete generations present unique challenges for population genetic modeling.

Purpose of the Study:

• To investigate the inbreeding effective population number for both autosomal and X-linked loci in dioecious populations.
• To compare two methods for calculating the probability of common parentage and their impact on genetic identity evolution.

Main Methods:

• Analysis of recursion relations for probabilities of genic identity.
• Comparison of effective population numbers under two distinct offspring identification schemes (sex-identified vs. not sex-identified).
• Development of a general symmetric framework for analyzing panmixia and monogamy models.

Main Results:

• Method (i), where offspring are identified by sex, correctly describes the evolution of genetic identity probabilities.
• Method (ii), which does not identify offspring by sex, has been more commonly applied but can yield different results.
• Agreement between the two methods is observed in many, but not all, population models.

Conclusions:

• The accurate calculation of inbreeding effective population size in dioecious species requires sex identification of offspring.
• Existing widely used models may need re-evaluation due to potential inaccuracies in genetic identity evolution.
• The developed framework offers a unified approach to studying various mating systems and their impact on population genetic parameters.