SynthesisPhilosophical transactions of the Royal Society of London. Series B, Biological sciences2020
How sperm competition shapes the evolution of testes and sperm: a meta-analysis.
Synthesis in Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 56 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
56 citing papers in PubMed, 1 synthesis or guideline pooled it, 146 citations in OpenAlex.
- Male alternative reproductive tactics and sperm competition: a meta-analysis.Biological reviews of the Cambridge Philosophical Society · 2022Pooled it
- Genes Related to Sperm Motility Are Under Recent Ongoing Selection in Two Shorebird Species With a Polygynous Mating System and Frequent Multiple Paternity.Molecular ecology · 2026Article
- Molecular Evolution of a Sex-Linked Inversion Polymorphism in Zebra Finches.Genome biology and evolution · 2026Article
- Characterization of the post-mating responses of Drosophila hydei, a species that lacks Sex-Peptide.Communications biology · 2026Article
- Experimental Evidence That Prenatal and Postnatal Developmental Stress Affects the Adult Seminal Fluid Proteome in a Precocial Bird.Molecular ecology · 2026Article
- Thirty Years of the Biology of Spermatozoa: The Rise and Future of an Evolutionary Paradigm.Ecology and evolution · 2026Article
- Dominance rank, facial morphology and testes size in male white-faced capuchins: evidence for pre- and post-mating competition.Proceedings. Biological sciences · 2025Article
- Exposure to novel females increases fecundity in adult male prairie voles.Hormones and behavior · 2025Article
- Mating system variation and gene expression in the male reproductive tract of Peromyscus mice.Molecular ecology · 2025Article
- Loss of Paired Weapons Leads to Larger Testes and a Lighter Load for Dispersal.Ecology and evolution · 2025Article
- Monogamy removes constraints on reproductive tissue investment imposed by intense sexual selection.Scientific reports · 2025Article
- Evolutionary Aspects of Sperm Physiology and Its Assessment.Methods in molecular biology (Clifton, N.J.) · 2025Review
- Article
- Sperm competition intensity shapes divergence in both sperm morphology and reproductive genes across murine rodents.Evolution; international journal of organic evolution · 2024Article
- Sexual size dimorphism affecting mate choice and reproduction in the pine sawyer beetle, Monochamus alternatus.Oecologia · 2024Article
- Article
- Tetrapod sperm length evolution in relation to body mass is shaped by multiple trade-offs.Nature communications · 2024Article
- Population density effects on gamete traits and fertilisation dynamics under varying sperm environments in mussels.Ecology and evolution · 2024Article
- Male allocation to ejaculation and mating effort imposes different life history trade-offs.PLoS biology · 2024Article
- Evolutionary trade-offs between testes size and parenting in Neotropical glassfrogs.Proceedings. Biological sciences · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 3 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Females of many species mate with multiple males, thereby inciting competition among ejaculates from rival males for fertilization. In response to increasing sperm competition, males are predicted to enhance their investment in sperm production. This prediction is so widespread that testes size (correcting for body size) is commonly used as a proxy of sperm competition, even in the absence of any other information about a species' reproductive behaviour. By contrast, a debate about whether sperm competition selects for smaller or larger sperm has persisted for nearly three decades, with empirical studies demonstrating every possible response. Here, we synthesize nearly 40 years of sperm competition research in a meta-analytical framework to determine how the evolution of sperm number (i.e. testes size) and sperm size (i.e. sperm head, midpiece, flagellum and total length) is influenced by varying levels of sperm competition across species. Our findings support the long-held assumption that higher levels of sperm competition are associated with relatively larger testes. We also find clear evidence that sperm competition is associated with increases in all components of sperm length. We discuss these results in the context of different theoretical predictions and general patterns in the breeding biology and selective environment of sperm. This article is part of the theme issue 'Fifty years of sperm competition'.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.