How sexual selection can drive the evolution of costly sperm ornamentation

  title={How sexual selection can drive the evolution of costly sperm ornamentation},
  author={Stefan L{\"u}pold and Mollie K. Manier and Nalini Puniamoorthy and Christopher Schoff and William T. Starmer and Shannon H. Buckley Luepold and John M. Belote and Scott Pitnick},
Post-copulatory sexual selection (PSS), fuelled by female promiscuity, is credited with the rapid evolution of sperm quality traits across diverse taxa. [] Key Method We also combine quantitative genetic analyses of interacting sex-specific traits in D. melanogaster with comparative analyses of the condition dependence of male and female reproductive potential across species with varying ornament size to reveal complex dynamics that may underlie sperm-length evolution. Our results suggest that producing few…

Sperm Cyst “Looping”: A Developmental Novelty Enabling Extreme Male Ornament Evolution

The discovery of a novel spermatogenic mechanism—sperm cyst looping—that enables males to produce relatively long sperm in short testis is reported, and speculation on the ecological selection pressures underlying the evolutionary origin and maintenance of this unique adaptation is speculated.

Can Sexual Selection Drive the Evolution of Sperm Cell Structure?

Experimental evolution uses the dung beetle Onthophagus taurus as a model to ask whether sexual selection can drive the divergence of sperm cell phenotype and suggests that different sperm cell components may respond independently to sexual selection and contribute to the divergent evolution of these extraordinary cells.

Multivariate Sexual Selection on Ejaculate Traits under Sperm Competition

There is the potential for adaptive evolution of ejaculate traits under sperm competition by exploiting the experimental tractability of a broadcast spawning marine invertebrate to characterize multivariate sexual selection on sperm traits when multiple ejaculates compete.

The evolution of sex peptide: sexual conflict, cooperation, and coevolution

Data suggest an evolutionary history involving the evolution of a dedicated SP‐sensing apparatus in the female reproductive tract that is likely to have evolved because it benefits females, rather than harms them, and the weight of evidence does not support the view that receipt of SP decreases female fitness.

Effect of population density on relationship between pre- and postcopulatory sexual traits

The results showed that population density affected sexual size dimorphism in both Artiodactyla and Carnivora, but not in Primates, and relative testis mass and sperm size were not affected by population density.

High male sexual investment as a driver of extinction in fossil ostracods

Ostracod species (small, bivalved crustaceans) with high sexual dimorphism, and therefore high male investment, had markedly higher extinction rates than low-investment species, indicating that sexual selection can be a substantial risk factor for extinction.

Population density and structure drive differential investment in pre‐ and postmating sexual traits in frogs

The intensifying struggle to monopolize fertilizations as more and more males clasp the same female to fertilize her eggs shifts male reproductive investment toward sperm production and away from male weaponry, explaining the trade‐off between pre‐ and postmating sexual traits in this much broader sample of anuran species.

Rapid Genomic Evolution Drives the Diversification of Male Reproductive Genes in Dung Beetles

There is rapid innovation at the genomic level even among closely related dung beetles, and the birth of scores of completely novel reproductive genes is reinforced by the recruitment of these genes for high expression in male reproductive tissues, especially in the accessory glands.

Conceptual developments in sperm competition: a very brief synopsis

  • G. Parker
  • Biology
    Philosophical Transactions of the Royal Society B
  • 2020
A short survey of conceptual developments in post-ejaculatory sexual selection is intended as a broad overview, mainly as a primer for new researchers.



Intensity of sexual selection along the anisogamy–isogamy continuum

The results confirm the big-sperm paradox by showing that the sex difference in sexual selection gradients decreases as sperm size increases and shows that most of the variation in measures of selection intensity is explained by sperm length and relative investment in sperm production.

Sperm-Female Coevolution in Drosophila

Using populations of Drosophila melanogaster selected for divergent sperm length or female sperm-storage organ length, experimentally show that male fertilization success is determined by an interaction between sperm and female morphology.

Female mediation of competitive fertilization success in Drosophila melanogaster

The results demonstrate that females do not simply provide a static arena for sperm competition but rather play an active and pivotal role in postcopulatory processes, and resolve the adaptive significance of genetic variation in female-mediated mechanisms of sperm handling.

A Mechanism of Extreme Growth and Reliable Signaling in Sexually Selected Ornaments and Weapons

A general mechanistic model for the evolution of exaggerated traits is presented, proposing that sensitivity to the insulin response pathway can explain variation among individuals and illustrating how enhanced sensitivity to insulin/IGF signaling in a growing ornament or weapon would cause heightened condition sensitivity and increased variability in expression among individuals.

Functional significance of seminal receptacle length in Drosophila melanogaster

Receptacle length did not alter the pattern of sperm precedence, which is consistent with data on the co‐evolution of sperm and female receptacle length, and a pattern of differential male fertilization success being principally determined by the interaction between these male and female traits.

No evidence for a trade‐off between sperm length and male premating weaponry

The relationship between precopulatory armaments and sperm length is evaluated in five taxa as well as meta‐analytically and there is no evidence for a negative or positive relationship between sperm length and male traits that are important in male–male contest competition.


Overall, eye‐span allometry exhibits significantly more change on the phylogeny than the other morphological traits, and this pattern is consistent with recent models that predict a strong relationship between sexual selection and the variance of ornamental traits and highlights the significance of eye‐ span allometry in intersexual and intrasexual signaling.

The allometry of ornaments and weapons.

This work shows how scaling exponents reflect the relative fitness advantages of ornaments vs. somatic growth by using a simple mathematical model of resource allocation during ontogeny and explains why interspecific allometries have consistently lower exponents than intraspecific ones.

Sexual Dimorphism and the Making of Oversized Male Characters in Beetles (Coleoptera)

Morphological observations were used to describe the general features of sexual dimorphism and the development of outstanding male characters at the family, genus, species, and subspecies levels and found that allometrically developed male fighting apparatus is the most conspicuous sexually dimorphic.

Female control : sexual selection by cryptic female choice

Cryptic female choice establishes a new bridge between sexual selection theory and reproductive physiology, in particular the physiological effects of male seminal products on female reproductive processes, such as sperm transport, oviposition, and remating.