Limits of artificial selection under unbalanced mating systems

Area of Science:

• Population Genetics
• Quantitative Genetics
• Evolutionary Biology

Background:

• Mating systems significantly influence the genetic structure and evolutionary trajectory of populations.
• Understanding gene fixation and loss dynamics is crucial for predicting evolutionary outcomes.
• Unbalanced mating systems, such as factorial mating (FM) and random loss of families (RS), present unique challenges in genetic modeling.

Purpose of the Study:

• To investigate the impact of unbalanced mating systems (FM and RS) on gene fixation probability (u(Π)) and fixation/loss time (t(Π)).
• To compare the genetic dynamics under these systems with those of random mating.
• To analyze how initial parental genotype combinations and gene frequencies affect fixation probabilities.

Main Methods:

• Theoretical investigation of gene fixation and loss probabilities under specified mating systems.
• Mathematical modeling to derive average fixation probabilities and fixation/loss times.
• Analysis of the influence of initial genetic configurations on population genetic parameters.

Main Results:

• Both FM and RS systems exhibit a lower average probability of gene fixation (u(Π)) compared to random mating.
• A wide range of u(Π) values (approaching one for many combinations) is observed for specific initial parental genotypes.
• Average u(Π) varies significantly across different parental genotypic combinations for a given gene frequency.
• These unbalanced systems demonstrably accelerate the time required for gene fixation or loss (t(Π)).

Conclusions:

• Unbalanced mating systems alter fundamental population genetic parameters, reducing the likelihood of gene fixation.
• The specific genetic makeup of the parental generation critically influences fixation probabilities under these systems.
• Factorial mating and random loss of families expedite the process of gene fixation or elimination within a population.