How Soon Hath Time… A History of Two "Seminal" Publications.

Geoff A Parker

doi:10.3390/cells10020287

Abstract

This review documents the history of the two papers written half a century ago that relate to this special issue of Cells. The first, “Sperm competition and its evolutionary consequences in the insects” (Biological Reviews, 1970), stressed that sexual selection continues after ejaculation, resulting in many adaptations (e.g., postcopulatory guarding phases, copulatory plugs, seminal fluid components that modify female reproduction, and optimal ejaculation strategies), an aspect not considered by Darwin in his classic treatise of 1871. Sperm competition has subsequently been studied in many taxa, and post-copulatory sexual selection is now considered an important sequel to Darwinian pre-copulatory sexual selection. The second, “The origin and evolution of gamete dimorphism and the male-female phenomenon” (Journal of Theoretical Biology, 1972) showed how selection, based on gamete competition between individuals, can give rise to anisogamy in an isogamous broadcast spawning ancestor. This theory, which has subsequently been developed in various ways, is argued to form the most powerful explanation of why there are two sexes in most multicellular organisms. Together, the two papers have influenced our general understanding of the evolutionary differentiation of the two forms of gametic cells, and the divergence of sexual strategies between males and females under sexual selection.

Highlights

At the request of the Editors of this Cells special issue, I attempt here to give a history of two early “seminal” papers
Reviews article, has been credited as the catalyst for the large field of post-copulatory sexual selection [2,3], i.e., sexual selection that continues after ejaculation
The male behaviour undoubtedly led me to think about sperm competition and its evolutionary consequences, which in turn generated an interest in the evolution of anisogamy, the key to the question of why there are so ubiquitously two sexes

Summary

Introduction

At the request of the Editors of this Cells special issue, I attempt here to give a history of two early “seminal” papers (a pun that has been used several times). Smith, appeared in the Journal of Theoretical Biology in 1972, and has had a role in establishing a theoretical foundation for the evolution of the gametic cells and the two sexes How these two papers germinated can be traced back to an early and enduring passion for natural history and animals, which led me eventually to my Ph.D. research at Bristol University on sexual selection in the yellow dung fly, Scathophaga (=Scatophaga) stercoraria L. The male behaviour undoubtedly led me to think about sperm competition (strictly, interejaculate competition, i.e., competition between ejaculates from different males) and its evolutionary consequences, which in turn generated an interest in the evolution of anisogamy (gametes of two different sizes in a given species), the key to the question of why there are so ubiquitously two sexes. A more extensive account of the contribution of the dung fly to the study of sperm competition is given elsewhere [29]

Sexual Selection and the Behavioural Ecology Revolution of the 1970s

Writing and Publication

Subsequent Developments

Findings

Final Thoughts