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Determination of the Mating Efficiency of Haploids in Saccharomyces cerevisiae

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Sex ratio evolution under probabilistic sex determination.

Tiago Paixão¹, Sujal S Phadke, Ricardo B R Azevedo

¹Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204-5001, USA. tmsearap@mail.uh.edu

Evolution; International Journal of Organic Evolution

|July 7, 2011

Summary

This summary is machine-generated.

Alleles for mixed offspring sex determination (SD) strategies can outcompete pure strategies but may prevent even sex ratios. Probabilistic SD explains skewed sex ratios in Tetrahymena thermophila populations with small effective sizes.

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Area of Science:

Evolutionary biology
Genetics

Background:

Sex allocation theory typically focuses on parental sex determination (SD) strategies.
Existing theories explain even sex ratios and conditions for biased ratios.

Purpose of the Study:

To investigate the evolutionary causes and consequences of mixed offspring SD strategies.
To analyze the impact of mixed SD strategies on population sex ratios.

Main Methods:

Developed a theoretical model of mixed offspring SD strategies.
Applied the model to analyze sex ratios in natural populations of Tetrahymena thermophila.

Main Results:

Alleles for mixed offspring SD strategies can outcompete pure strategies.
Mixed SD strategies can impose constraints preventing even sex ratios.
Probabilistic SD sufficiently explains skewed sex ratios in small T. thermophila populations.

Conclusions:

Mixed offspring SD strategies may be more prevalent than previously thought.
Genetic drift plays a significant role in the evolution of sex ratios.
Probabilistic sex determination is a key factor in understanding skewed sex ratios in certain populations.