Related Experiment Video
Updated: Jul 15, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila
Published on: August 22, 2013
Sperm competition and the evolution of ejaculate composition
Erin Cameron1, Troy Day, Locke Rowe
1Department of Biology, McGill University, Montreal, Quebec, Canada. erin.cameron@mcgill.ca
Abstract:
We present a model of sperm competition that incorporates both sperm and nonsperm parts of the ejaculate. Our primary focus is on determining how ejaculate composition and size evolves as a function of the effects of seminal fluid on male reproductive success and as a function of asymmetry in sperm usage by females. The model predicts that different patterns of investment in sperm and seminal products are expected to evolve as a function of the bias in sperm usage by females. It also predicts the evolution of distinct patterns in ejaculate composition depending on the function of seminal fluid. In the discussion, we highlight a number of potential approaches for testing the theory that we develop.
Related Concept Videos
Sperm Structure and Semen Composition
Sperm Transport
The maturation phase occurs in the epididymis, where sperm...
Spermatogenesis
Spermatogenesis
The process of spermatogenesis can be divided into mitosis, meiosis, and spermiogenesis. During mitosis, the spermatogonia or stem cells divide to produce two identical daughter cells, type A and B spermatogonia. Type-A...
Fertilization
Natural Selection and Mating Preferences
Females, due to their biological roles in conception, pregnancy, and nursing, inherently...

