Related Experiment Video
Updated: Jul 5, 2026

Determination of the Mating Efficiency of Haploids in Saccharomyces cerevisiae
Published on: December 2, 2022
Gametic conflict versus contact in the evolution of anisogamy
1Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA. priyai@stanford.edu
Abstract:
Anisogamy refers to gametes that differ in size, and characterizes the difference between males and females. The evolution of aniosgamy is widely interpreted as involving conflict between gamete producers with small sperm parasitizing on the investment made by the eggs. Using a population genetic model for evolution at a locus that codes jointly for sperm and egg sizes of a hermaphrodite, we show that the origin of anisogamy in an externally spawning population need not involve conflict between gamete producers. Gamete size dimorphism may be an adaptation that increases gamete encounter rates when large zygotes are selected, and we show this in a mechanistically general individual selection model. We use the Vance survival function without specific allometric assumptions to model the zygote fitness dependence on its size, and hence obtain ecological and life-history correlates of isogamy and anisogamy, which we successfully compare with data from Volvocales.
Related Concept Videos
Genetics of Speciation
Understanding Species and Reproductive Barriers
Nondisjunction
Nondisjunction
Nondisjunction
Crossing Over
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...

