1
|
Somjee U, Marting P, Anzaldo S, Simmons LW, Painting CJ. Extreme range in adult body size reveals hidden trade-offs among sexually selected traits. Evolution 2024:qpae084. [PMID: 38900629 DOI: 10.1093/evolut/qpae084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 05/13/2024] [Accepted: 05/24/2024] [Indexed: 06/22/2024]
Abstract
Sexually selected weapons used to monopolize mating opportunities are predicted to trade-off with traits used in competition for fertilization. Yet, the limited size range typically found among adults of a species often precludes clear comparisons between population-level and individual-level relative trait investment. The jousting weevil, Brentus anchorago (Coleoptera: Brentidae), varies more than 26-fold in body mass, which is among the most extreme adult body size ranges of any solitary terrestrial species. We reveal a trade-off at a population level: hypermetric scaling in male weapons (slope = 1.59) and a closely mirrored reversal in allocation to postcopulatory traits (slope = 0.54). Yet, at the individual level, we find the opposite pattern; males that invest relatively more in weapons for their size class also invest more in postcopulatory traits. Across 36 dung beetle and 41 brentine weevil species, we find the allometric slope explains more trait variation at larger body size ranges; in brentines, population-level scaling patterns become more detectable in species with a larger range in adult body size. Our findings reveal that population-level allometries and individual-level trade-offs can both be important in shaping relative trait allocation; we highlight that the adult body size range is rarely examined but may be integral to gaining a deeper understanding of trade-offs in reproductive allocation.
Collapse
Affiliation(s)
- Ummat Somjee
- Department of Integrative Biology, University of Texas, Austin, TX, United States
- Smithsonian Tropical Research Institute, Balboa, Panama
| | - Peter Marting
- Department of Biological Sciences, Auburn University, Auburn, AL, United States
| | - Salvatore Anzaldo
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Leigh W Simmons
- School of Biological Sciences, University of Western Australia, Perth, WA, Australia
| | | |
Collapse
|
2
|
Laugen AT, Hosken DJ, Reinhold K, Schwarzenbach GA, Hoeck PEA, Bussière LF, Blanckenhorn WU, Lüpold S. Sperm competition in yellow dung flies: No consistent effect of sperm size. J Evol Biol 2022; 35:1309-1318. [PMID: 35972882 DOI: 10.1111/jeb.14073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 07/09/2022] [Accepted: 07/12/2022] [Indexed: 01/07/2023]
Abstract
The male competition for fertilization that results from female multiple mating promotes the evolution of increased sperm numbers and can impact sperm morphology, with theory predicting that longer sperm can at times be advantageous during sperm competition. If so, males with longer sperm should sire more offspring than competitors with shorter sperm. Few studies have directly tested this prediction, and findings are inconsistent. Here we assessed whether longer sperm provide a competitive advantage in the yellow dung fly (Scathophaga stercoraria; Diptera: Scathophagidae). Initially, we let brothers with different temperature-mediated mean sperm lengths compete - thus minimizing confounding effects of genetic background - and found no clear advantage of longer sperm. We then used flies from lines subjected to bidirectional selection on phenoloxidase activity that had shown correlated evolutionary responses in sperm and female spermathecal duct lengths. This experiment also yielded no main effect of sperm size on siring success. Instead, there was a trend for a shorter-sperm advantage, but only when competing in females with longer spermathecal ducts. Our data corroborated many previously reported findings (last-male precedence, effects of copula duration and body size), suggesting our failure to find sperm size effects is not inherently due to our experimental protocols. We conclude that longer sperm are not competitively superior in yellow dung flies under most circumstances, and that, consistent with previous work, in this species competitive fertilization success is primarily determined by the relative numbers of sperm competing.
Collapse
Affiliation(s)
- Ane T Laugen
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland.,Centre for Coastal Research, Department of Natural Sciences, University of Agder, Kristiansand, Norway
| | - David J Hosken
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland.,Centre for Ecology and Conservation, University of Exeter in Cornwall, Penryn, UK
| | - Klaus Reinhold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland.,Evolutionsbiologie, Universität Bielefeld, Bielefeld, Germany
| | - Gioia A Schwarzenbach
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland
| | - Paquita E A Hoeck
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland
| | - Luc F Bussière
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland.,Biology and Environmental Sciences, University of Gothenburg and Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
| | - Wolf U Blanckenhorn
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland
| | - Stefan Lüpold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland
| |
Collapse
|
3
|
Walters RJ, Berger D, Blanckenhorn WU, Bussière LF, Rohner PT, Jochmann R, Thüler K, Schäfer MA. Growth rate mediates hidden developmental plasticity of female yellow dung fly reproductive morphology in response to environmental stressors. Evol Dev 2022; 24:3-15. [PMID: 35072984 PMCID: PMC9285807 DOI: 10.1111/ede.12396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/19/2021] [Accepted: 11/24/2021] [Indexed: 01/08/2023]
Abstract
Understanding how environmental variation influences even cryptic traits is important to clarify the roles of selection and developmental constraints in past evolutionary divergence and to predict future adaptation under environmental change. Female yellow dung flies (Scathophaga stercoraria) typically have three sperm storage compartments (3S), but occasionally four (4S). More spermathecae are thought to be a female adaptation facilitating sperm sorting after mating, but the phenotype is very rare in nature. We manipulated the flies' developmental environment by food restriction, pesticides, and hot temperatures to investigate the nature and extent of developmental plasticity of this trait, and whether spermatheca expression correlates with measures of performance and developmental stability, as would be expected if 4S expression is a developmental aberration. The spermathecal polymorphism of yellow dung fly females is heritable, but also highly developmentally plastic, varying strongly with rearing conditions. 4S expression is tightly linked to growth rate, and weakly positively correlated with fluctuating asymmetry of wings and legs, suggesting that the production of a fourth spermatheca could be a nonadaptive developmental aberration. However, spermathecal plasticity is opposite in the closely related and ecologically similar Scathophaga suilla, demonstrating that overexpression of spermathecae under developmental stress is not universal. At the same time, we found overall mortality costs as well as benefits of 4S pheno‐ and genotypes (also affecting male siblings), suggesting that a life history trade‐off may potentially moderate 4S expression. We conclude that the release of cryptic genetic variation in spermatheca number in the face of strong environmental variation may expose hidden traits (here reproductive morphology) to natural selection (here under climate warming or food augmentation). Once exposed, hidden traits can potentially undergo rapid genetic assimilation, even in cases when trait changes are first triggered by random errors that destabilize developmental processes. Female yellow dung flies naturally vary in number of sperm storage compartments (3S or 4S). This spermathecal polymorphism is strongly heritable but also developmentally plastic. 4S expression is linked to growth rate and weakly correlated with fluctuating asymmetry, so potentially a developmental aberration. There are mortality costs as well as benefits for 4S phenotypes, suggesting adaptive life‐history trade‐offs. Spermathecal plasticity differs in the closely related and ecologically similar Scathophaga suilla. Environmental changes can expose hidden traits with initially no function to natural selection.
Collapse
Affiliation(s)
- Richard J. Walters
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
- Centre for Environmental and Climate Research Lund University Lund Sweden
| | - David Berger
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
- Evolutionary Biology Centre University of Uppsala Uppsala Sweden
| | - Wolf U. Blanckenhorn
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Luc F. Bussière
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
- Biological and Environmental Sciences University of Stirling Stirling Scotland UK
- Biology and Environmental Sciences University of Gothenburg Gothenburg Sweden
| | - Patrick T. Rohner
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
- Department of Biology Indiana University Bloomington Indiana USA
| | - Ralf Jochmann
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Karin Thüler
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Martin A. Schäfer
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| |
Collapse
|
4
|
Blanckenhorn WU, Berger D, Rohner PT, Schäfer MA, Akashi H, Walters RJ. Comprehensive thermal performance curves for yellow dung fly life history traits and the temperature-size-rule. J Therm Biol 2021; 100:103069. [PMID: 34503806 DOI: 10.1016/j.jtherbio.2021.103069] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/27/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
Ambient temperature strongly determines the behaviour, physiology, and life history of all organisms. The technical assessment of organismal thermal niches in form of now so-called thermal performance curves (TPC) thus has a long tradition in biological research. Nevertheless, several traits do not display the idealized, intuitive dome-shaped TPC, and in practice assessments often do not cover the entire realistic or natural temperature range of an organism. We here illustrate this by presenting comprehensive sex-specific TPCs for the major (juvenile) life history traits of yellow dung flies (Scathophaga stercoraria; Diptera: Scathophagidae). This concerns estimation of prominent biogeographic rules, such as the temperature-size-rule (TSR), the common phenomenon in ectothermic organisms that body size decreases as temperature increases. S. stercoraria shows an untypical asymptotic TPC of continuous body size increase with decreasing temperature without a peak (optimum), thus following the TSR throughout their entire thermal range (unlike several other insects presented here). Egg-to-adult mortality (our best fitness estimator) also shows no intermediate maximum. Both may relate to this fly entering pupal winter diapause below 12 °C. While development time presents a negative exponential relationship with temperature, development rate and growth rate typify the classic TPC form for this fly. The hitherto largely unexplored close relative S. suilla with an even more arctic distribution showed very similar responses, demonstrating large overlap among two ecologically similar, coexisting dung fly species, thus implying limited utility of even complete TPCs for predicting species distribution and coexistence.
Collapse
Affiliation(s)
- Wolf U Blanckenhorn
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
| | - David Berger
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland; Evolutionary Biology Centre, University of Uppsala, Norbyvägen 18D, S-752 36, Uppsala, Sweden
| | - Patrick T Rohner
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland; Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Martin A Schäfer
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Hiroshi Akashi
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland; Department of Biological Science and Technology, Tokyo University of Science, Tokyo, 125-8585, Japan
| | - Richard J Walters
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland; Centre for Environmental and Climate Research, Lund University, Sweden
| |
Collapse
|
5
|
Mrinalini, Koh CY, Puniamoorthy N. Rapid Genomic Evolution Drives the Diversification of Male Reproductive Genes in Dung Beetles. Genome Biol Evol 2021; 13:6329639. [PMID: 34426833 PMCID: PMC8382682 DOI: 10.1093/gbe/evab172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2021] [Indexed: 11/22/2022] Open
Abstract
The molecular basis for the evolution of novel phenotypes is a central question in evolutionary biology. In recent years, dung beetles have emerged as models for novel trait evolution as they possess distinct precopulatory traits such as sexually dimorphic horns on their head and thorax. Here, we use functional and evolutionary genomics to investigate the origins and the evolution of postcopulatory reproductive traits in male dung beetles. Male ejaculates that underlie postcopulatory sexual selection are excellent candidates to study novel trait evolution as they are complex, fast evolving, and often highly divergent in insects. We assemble de novo transcriptomes of male accessory glands and testes of a widespread dung beetle, Catharsius molossus, and we perform an evolutionary analysis of closely and distantly related insect genomes. Our results show there is rapid innovation at the genomic level even among closely related dung beetles. Genomic expansion and contraction drive the divergence of male reproductive traits and their functions. 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. We find that male accessory glands of C. molossus are specialized for secretory function and express female, egg, and embryo-related genes as well as serine protease inhibitors, whilst the testes are specialized for spermatogenesis and sperm function. Finally, we touch upon putative functions of these evolutionary novelties using structure-function analysis as these proteins bear no homology to any other known proteins.
Collapse
Affiliation(s)
- Mrinalini
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Cho Yeow Koh
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Nalini Puniamoorthy
- Department of Biological Sciences, National University of Singapore, Singapore
| |
Collapse
|
6
|
Okuzaki Y. Effects of body size divergence on male mating tactics in the ground beetle Carabus japonicus. Evolution 2021; 75:2269-2285. [PMID: 34231214 DOI: 10.1111/evo.14302] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 11/27/2022]
Abstract
Animal body size is involved in reproduction in various ways. Carabus japonicus exhibits considerable variation in adult body size across geographical locations depending on the larval environment. To investigate the effects of body size divergence on male mating traits, spermatophore deposition and weight, copulation duration, and post-copulatory mounting were observed using male-female pairs from C. japonicus populations with different body sizes. Then, variables with high predictive power on the mating traits were identified from individual characteristics. When the male was slightly smaller than his mate, spermatophore deposition likely succeeded, suggesting that mechanical size-assortative insemination determined male body size. Although male reproductive organ size was positively correlated with male body size, spermatophore weight was not significantly affected by male body size, whereas copulation duration decreased with increasing male body size. Enlarged males, with a high capacity for spermatophore production, could increase paternity by decreasing copulation duration and increasing mating frequency. Such shifts in mating tactics would alter selection pressures of intra- and intersexual interactions (e.g., sperm competition and sexual conflict). Genital dimensions also affected mating traits other than copulatory duration. Thus, ecological heterogeneity has the potential to lead to divergences in sexual traits, such as genital morphology, through body size divergence.
Collapse
Affiliation(s)
- Yutaka Okuzaki
- Department of General Systems Studies, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, Japan
| |
Collapse
|
7
|
Demont M, Ward PI, Blanckenhorn WU, Lüpold S, Martin OY, Bussière LF. How biases in sperm storage relate to sperm use during oviposition in female yellow dung flies. Behav Ecol 2021. [DOI: 10.1093/beheco/arab026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Abstract
Precise mechanisms underlying sperm storage and utilization are largely unknown, and data directly linking stored sperm to paternity remain scarce. We used competitive microsatellite PCR to study the effects of female morphology, copula duration and oviposition on the proportion of stored sperm provided by the second of two copulating males (S2) in Scathophaga stercoraria (Diptera: Scathophagidae), the classic model for sperm competition studies. We genotyped all offspring from potentially mixed-paternity clutches to establish the relationship between a second male’s stored sperm (S2) and paternity success (P2). We found consistent skew in sperm storage across the three female spermathecae, with relatively more second-male sperm stored in the singlet spermatheca than in the doublet spermathecae. S2 generally decreased with increasing spermathecal size, consistent with either heightened first-male storage in larger spermathecae, or less efficient sperm displacement in them. Additionally, copula duration and several two-way interactions influenced S2, highlighting the complexity of postcopulatory processes and sperm storage. Importantly, S2 and P2 were strongly correlated. Manipulation of the timing of oviposition strongly influenced observed sperm-storage patterns, with higher S2 when females laid no eggs before being sacrificed than when they oviposited between copulations, an observation consistent with adaptive plasticity in insemination. Our results identified multiple factors influencing sperm storage, nevertheless suggesting that the proportion of stored sperm is strongly linked to paternity (i.e., a fair raffle). Even more detailed data in this vein are needed to evaluate the general importance of sperm competition relative to cryptic female choice in postcopulatory sexual selection.
Collapse
Affiliation(s)
- Marco Demont
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel Winterthurerstrasse 190, Zurich, Switzerland
- Department of Biology and Institute of Integrative Biology, ETH Zurich, Universitätsstrasse 16, 8092 Zurich, Switzerland
| | - Paul I Ward
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel Winterthurerstrasse 190, Zurich, Switzerland
| | - Wolf U Blanckenhorn
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel Winterthurerstrasse 190, Zurich, Switzerland
| | - Stefan Lüpold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel Winterthurerstrasse 190, Zurich, Switzerland
| | - Oliver Y Martin
- Department of Biology and Institute of Integrative Biology, ETH Zurich, Universitätsstrasse 16, 8092 Zurich, Switzerland
| | - Luc F Bussière
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel Winterthurerstrasse 190, Zurich, Switzerland
- Biological and Environmental Sciences, University of Stirling, Stirling, Scotland, UK
- Biology and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
8
|
Parker GA. How Soon Hath Time… A History of Two "Seminal" Publications. Cells 2021; 10:cells10020287. [PMID: 33535413 PMCID: PMC7912719 DOI: 10.3390/cells10020287] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 12/19/2022] Open
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.
Collapse
Affiliation(s)
- Geoff A Parker
- Department of Evolution, Ecology and Behaviour, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
| |
Collapse
|
9
|
Simmons LW, Wedell N. Fifty years of sperm competition: the structure of a scientific revolution. Philos Trans R Soc Lond B Biol Sci 2020; 375:20200060. [PMID: 33070719 DOI: 10.1098/rstb.2020.0060] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Affiliation(s)
- Leigh W Simmons
- Centre for Evolutionary Biology, The University of Western Australia, Crawley 6009, Australia
| | - Nina Wedell
- Centre for Ecology and Conservation, University of Exeter, Cornwall, Penryn TR10 9FE, UK
| |
Collapse
|
10
|
Birkhead TR, Montgomerie R. Three decades of sperm competition in birds. Philos Trans R Soc Lond B Biol Sci 2020; 375:20200208. [PMID: 33070724 DOI: 10.1098/rstb.2020.0208] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the three decades, since Birkhead and Møller published Sperm competition in birds (1992, Academic Press) more than 1000 papers have been published on this topic, about half of these being empirical studies focused on extrapair paternity. Both technological innovations and theory have moved the field forward by facilitating the study of both the mechanisms underlying sperm competition in both sexes, and the ensuing behavioural and morphological adaptations. The proliferation of studies has been driven partly by the diversity of both behaviours and morphologies in birds that have been influenced by sperm competition, but also by the richness of the theory developed by Geoff Parker over the past 50 years. This article is part of the theme issue 'Fifty years of sperm competition'.
Collapse
Affiliation(s)
- Tim R Birkhead
- Department of Animal and Plant Sciences, The University of Sheffield, Sheffield S10 2TN, UK
| | | |
Collapse
|