Concepedia

Sperm-Female Coevolution in <i>Drosophila</i>

Science · 2002 · 468 citations · 27 references

TL;DR

Rapid evolution of reproductive traits is driven by sexual selection from male‑female interactions, yet the specific selection forces on sex‑specific phenotypes remain unclear. The study tests whether male fertilization success depends on the interaction between sperm and female morphology by selecting Drosophila melanogaster populations for divergent sperm length or female sperm‑storage organ length. The authors used these selected populations to experimentally assess how sperm and female morphology jointly determine fertilization success. Sperm length evolved as a correlated response to selection on the female reproductive tract, and giant sperm tails evolved because female tracts bias paternity toward males with longer sperm.

Abstract

Rapid evolution of reproductive traits has been attributed to sexual selection arising from interaction between the sexes. However, little is known about the nature of selection driving the evolution of interacting sex-specific phenotypes. Using populations of Drosophila melanogaster selected for divergent sperm length or female sperm-storage organ length, we experimentally show that male fertilization success is determined by an interaction between sperm and female morphology. In addition, sperm length evolution occurred as a correlated response to selection on the female reproductive tract. Giant sperm tails are the cellular equivalent of the peacock's tail, having evolved because females evolved reproductive tracts that selectively bias paternity in favor of males with longer sperm.