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Belcik JT, Ashley MV. Riverscape genetics of the orangethroat darter complex. JOURNAL OF FISH BIOLOGY 2024; 104:837-850. [PMID: 37971888 DOI: 10.1111/jfb.15619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 09/16/2023] [Accepted: 11/15/2023] [Indexed: 11/19/2023]
Abstract
Freshwater darters belonging to the orangethroat darter species complex, or Ceasia, are widely distributed in the Central and Southern United States, with ranges that span both glaciated and unglaciated regions. Up to 15 species have been recognized in the complex, with one, Etheostoma spectabile, having a widespread northern distribution and another, Etheostoma pulchellum, having a sizeable southern distribution. The other species in the complex have much more restricted distributions in unglaciated regions of the Central Highlands. We sampled 384 darters from 52 sites covering much of the range of Ceasia and evaluated patterns of genetic diversity, genetic structure, and pre- and post-glacial patterns of range contraction and expansion. We anticipated finding much stronger signals of genetic differentiation and diversification in unglaciated regions, given the higher species diversity and levels of endemism reported there. Surprisingly, microsatellite genotyping revealed two well-differentiated genetic clusters of E. spectabile in samples from glaciated regions, one confined to the Illinois River basin and another found in the Wabash drainage and Great Lakes tributaries. This suggests that there was expansion from two isolated glacial refugia, with little subsequent post-glacial gene flow. Fish collected from throughout the unglaciated region were less genetically differentiated. Fish assigned to Etheostoma burri and Etheostoma uniporum based on collection sites and morphological characters were not genetically differentiated from E. spectabile samples from the region. Hybridization and introgression occurring in the Central Highlands may confound genetic delineation of species in this region of high endemism and diversity.
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Affiliation(s)
- John T Belcik
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
- U.S. Army Corps of Engineers Chicago District, Chicago, Illinois, USA
| | - Mary V Ashley
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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2
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Black TN, Rastogi A, Saegert A, Dib J, Moran RL. Male recognition of conspecific female chemical cues in a diverse clade of freshwater fishes. JOURNAL OF FISH BIOLOGY 2024; 104:883-886. [PMID: 37906501 DOI: 10.1111/jfb.15600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/19/2023] [Accepted: 10/25/2023] [Indexed: 11/02/2023]
Abstract
Where orangethroat darters (Etheostoma: Ceasia) and rainbow darters (Etheostoma caeruleum) co-occur, males prefer conspecific over heterospecific females. The cues males use to identify conspecific females remain unclear. We conducted behavioral trials to ask whether chemical cues function in conspecific recognition. We found that males from three orangethroat darter species preferentially associate with female scent over a control. Our results support the use of olfaction in conspecific identification in the orangethroat clade and contribute to our understanding of signals that may facilitate species recognition and underlie the evolution of behavioral isolation.
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Affiliation(s)
- Taylor N Black
- Department of Biology, Texas A&M University, College Station, Texas, USA
| | - Aakriti Rastogi
- Department of Biology, Texas A&M University, College Station, Texas, USA
| | - Abby Saegert
- Department of Biology, Texas A&M University, College Station, Texas, USA
| | - Joseph Dib
- Department of Biology, Texas A&M University, College Station, Texas, USA
| | - Rachel L Moran
- Department of Biology, Texas A&M University, College Station, Texas, USA
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3
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McEachin S, Drury JP, Grether GF. Competitive Displacement and Agonistic Character Displacement, or the Ghost of Interference Competition. Am Nat 2024; 203:335-346. [PMID: 38358816 DOI: 10.1086/728671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
AbstractInterference competition can drive species apart in habitat use through competitive displacement in ecological time and agonistic character displacement (ACD) over evolutionary time. As predicted by ACD theory, sympatric species of rubyspot damselflies (Hetaerina spp.) that respond more aggressively to each other in staged encounters differ more in microhabitat use. However, the same pattern could arise from competitive displacement if dominant species actively exclude subordinate species from preferred microhabitats. The degree to which habitat partitioning is caused by competitive displacement can be assessed with removal experiments. We carried out removal experiments with three species pairs of rubyspot damselflies. With competitive displacement, removing dominant species should allow subordinate species to shift into the dominant species' microhabitat. Instead, we found that species-specific microhabitat use persisted after the experimental removals. Thus, the previously documented association between heterospecific aggression and microhabitat partitioning in this genus is most likely a product of divergence in habitat preferences caused by interference competition in the evolutionary past.
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4
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Anderson CB, Ospina O, Beerli P, Lemmon AR, Banker SE, Hassinger AB, Dye M, Kortyna ML, Lemmon EM. The population genetics of speciation by cascade reinforcement. Ecol Evol 2023; 13:e9773. [PMID: 36789346 PMCID: PMC9905665 DOI: 10.1002/ece3.9773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 12/22/2022] [Accepted: 01/09/2023] [Indexed: 02/10/2023] Open
Abstract
Species interactions drive diverse evolutionary outcomes. Speciation by cascade reinforcement represents one example of how species interactions can contribute to the proliferation of species. This process occurs when the divergence of mating traits in response to selection against interspecific hybridization incidentally leads to reproductive isolation among populations of the same species. Here, we investigated the population genetic outcomes of cascade reinforcement in North American chorus frogs (Hylidae: Pseudacris). Specifically, we estimated the frequency of hybridization among three taxa, assessed genetic structure within the focal species, P. feriarum, and ascertained the directionality of gene flow within P. feriarum across replicated contact zones via coalescent modeling. Through field observations and preliminary experimental crosses, we assessed whether hybridization is possible under natural and laboratory conditions. We found that hybridization occurs among P. feriarum and two conspecifics at a low rate in multiple contact zones, and that gene flow within the former species is unidirectional from allopatry into sympatry with these other species in three of four contact zones studied. We found evidence of substantial genetic structuring within P. feriarum including a divergent western allopatric cluster, a behaviorally-distinct sympatric South Carolina cluster, and several genetically-overlapping clusters from the remainder of the distribution. Furthermore, we found sub-structuring between reinforced and nonreinforced populations in the two most intensely-sampled contact zones. Our literature review indicated that P. feriarum hybridizes with at least five heterospecifics at the periphery of its range providing a mechanism for further intraspecific diversification. This work strengthens the evidence for cascade reinforcement in this clade, revealing the geographic and genetic landscape upon which this process can contribute to the proliferation of species.
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Affiliation(s)
- Carlie B. Anderson
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
| | - Oscar Ospina
- Department of Biostatistics and BioinformaticsMoffitt Cancer CenterTampaFloridaUSA
| | - Peter Beerli
- Department of Scientific ComputingFlorida State UniversityTallahasseeFloridaUSA
| | - Alan R. Lemmon
- Department of Scientific ComputingFlorida State UniversityTallahasseeFloridaUSA
| | - Sarah E. Banker
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA,Pfizer Clinical Pharmacogenomics GroupGrotonConnecticutUSA
| | - Alyssa Bigelow Hassinger
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA,Varigen BiosciencesMiddletonWisconsinUSA
| | - Mysia Dye
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
| | - Michelle L. Kortyna
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
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5
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Calabrese GM, Pfennig KS. Female mate preferences do not predict male sexual signals across populations. Behav Ecol 2021. [DOI: 10.1093/beheco/arab082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Abstract
New species can arise when female preferences and male sexual signals diverge across populations and thereby reduce mating between populations. Under this hypothesized mechanism for speciation, mate preferences and sexual signals should be correlated, but divergent, across populations. We evaluated this prediction using spadefoot toads (Spea multiplicata). We measured a sexually selected male signal (call rate) for which female preferences are known to vary across populations in response to the risk of hybridizing with another species. Contrary to expectation, we found no correlation between male call rate and female preferences across populations. We discuss possible mechanisms of this pattern, including the effect of gene flow from heterospecifics on male call rate. Our results suggest that, even when populations vary in mating traits, the independent evolution of female preferences and male sexual signals might impede reproductive isolation between populations.
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Affiliation(s)
- Gina M Calabrese
- Department of Biology, University of North Carolina , CB#3280, Chapel Hill, NC 27599-3280 , USA
| | - Karin S Pfennig
- Department of Biology, University of North Carolina , CB#3280, Chapel Hill, NC 27599-3280 , USA
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6
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McEachin S, Drury JP, Anderson CN, Grether GF. Mechanisms of reduced interspecific interference between territorial species. Behav Ecol 2021. [DOI: 10.1093/beheco/arab115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Interspecific territoriality has complex ecological and evolutionary consequences. Species that interact aggressively often exhibit spatial or temporal shifts in activity that reduce the frequency of costly encounters. We analyzed data collected over a 13-year period on 50 populations of rubyspot damselflies (Hetaerina spp.) to examine how rates of interspecific fighting covary with fine-scale habitat partitioning and to test for agonistic character displacement in microhabitat preferences. In most sympatric species, interspecific fights occur less frequently than expected based on the species’ relative densities. Incorporating measurements of spatial segregation and species discrimination into the calculation of expected frequencies accounted for most of the reduction in interspecific fighting (subtle differences in microhabitat preferences could account for the rest). In 23 of 25 sympatric population pairs, we found multivariate differences between species in territory microhabitat (perch height, stream width, current speed, and canopy cover). As predicted by the agonistic character displacement hypothesis, sympatric species that respond more aggressively to each other in direct encounters differ more in microhabitat use and have higher levels of spatial segregation. Previous work established that species with the lowest levels of interspecific fighting have diverged in territory signals and competitor recognition through agonistic character displacement. In the other species pairs, interspecific aggression appears to be maintained as an adaptive response to reproductive interference, but interspecific fighting is still costly. We now have robust evidence that evolved shifts in microhabitat preferences also reduce the frequency of interspecific fighting.
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Affiliation(s)
- Shawn McEachin
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles Young Drive South, Los Angeles, CA, USA
| | | | | | - Gregory F Grether
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles Young Drive South, Los Angeles, CA, USA
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7
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Speciation by sexual selection: 20 years of progress. Trends Ecol Evol 2021; 36:1153-1163. [PMID: 34607719 DOI: 10.1016/j.tree.2021.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/26/2021] [Accepted: 09/01/2021] [Indexed: 11/21/2022]
Abstract
Twenty years ago, a seminal paper summarized the role of sexual selection in speciation as the coordinated evolution of (male) courtship signals and (female) preferences leading to prezygotic (behavioral) isolation between divergent lineages. Here, we discuss areas of progress that inspire an updated perspective. First, research has identified multiple mechanisms of sexual selection, in addition to female mate choice, that drive the origin and maintenance of species. Second, reviews and empirical data now conclude that sexual selection alone will rarely lead to reproductive isolation without ecological divergence, and we discuss the assumptions and possible exceptions underlying that conclusion. Finally, we consider the variable ways in which sexual selection contributes to divergence according to the spatial, temporal, social, ecological, and genomic context of speciation.
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8
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Zambre AM, Khandekar A, Sanap R, O'Brien C, Snell-Rood EC, Thaker M. Asymmetric interspecific competition drives shifts in signalling traits in fan-throated lizards. Proc Biol Sci 2020; 287:20202141. [PMID: 33290678 DOI: 10.1098/rspb.2020.2141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Interspecific competition can occur when species are unable to distinguish between conspecific and heterospecific mates or competitors when they occur in sympatry. Selection in response to interspecific competition can lead to shifts in signalling traits-a process called agonistic character displacement. In two fan-throated lizard species-Sitana laticeps and Sarada darwini-females are morphologically indistinguishable and male agonistic signalling behaviour is similar. Consequently, in areas where these species overlap, males engage in interspecific aggressive interactions. To test whether interspecific male aggression between Si. laticeps and Sa. darwini results in agonistic character displacement, we quantified species recognition and signalling behaviour using staged encounter assays with both conspecifics and heterospecifics across sympatric and allopatric populations of both species. We found an asymmetric pattern, wherein males of Si. laticeps but not Sa. darwini showed differences in competitor recognition and agonistic signalling traits (morphology and behaviour) in sympatry compared with allopatry. This asymmetric shift in traits is probably due to differences in competitive abilities between species and can minimize competitive interactions in zones of sympatry. Overall, our results support agonistic character displacement, and highlight the role of asymmetric interspecific competition in driving shifts in social signals.
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Affiliation(s)
- Amod M Zambre
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Minneapolis, MN, USA.,Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, India
| | - Akshay Khandekar
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, India
| | - Rajesh Sanap
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, India
| | - Clairissa O'Brien
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Minneapolis, MN, USA
| | - Emilie C Snell-Rood
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Minneapolis, MN, USA
| | - Maria Thaker
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, India
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9
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St John ME, Fuller RC. Asymmetric reinforcement in Lucania killifish: assessing reproductive isolation when both sexes choose. Curr Zool 2020; 67:215-224. [PMID: 33854539 PMCID: PMC8026148 DOI: 10.1093/cz/zoaa049] [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] [Received: 06/13/2020] [Accepted: 08/25/2020] [Indexed: 11/21/2022] Open
Abstract
Reinforcement can occur when maladaptive hybridization in sympatry favors the evolution of conspecific preferences and target traits that promote behavioral isolation (BI). In many systems, enhanced BI is due to increased female preference for conspecifics. In others, BI is driven by male preference, and in other systems both sexes exert preferences. Some of these patterns can be attributed to classic sex-specific costs and benefits of preference. Alternatively, sex differences in conspecific preference can emerge due to asymmetric postzygotic isolation (e.g., hybrid offspring from female A × male B have lower fitness than hybrid offspring from female B × male A), which can lead to asymmetric BI (e.g., female A and male B are less likely to mate than female B and male A). Understanding reinforcement requires understanding how conspecific preferences evolve in sympatry. Yet, estimating conspecific preferences can be difficult when both sexes are choosy. In this study, we use Lucania killifish to test the hypothesis that patterns of reinforcement are driven by asymmetric postzygotic isolation between species. If true, we predicted that sympatric female Lucania goodei and sympatric male L. parva should have lower levels of BI compared with their sympatric counterparts, as they produce hybrid offspring with the highest fitness. To address the problem of measuring BI when both sexes are choosy, we inferred the contribution to BI of each partner using assays where one sex in the mating pair comes from an allopatric population with potentially low preference, whereas the other comes from a sympatric population with high preference. For one hybrid cross direction, we found that both female L. parva and male L. goodei have high contributions to BI in sympatry. In the other hybrid cross direction, we found that only female L. goodei contribute to BI. Sympatric male L. parva readily engaged in hybrid spawnings with allopatric L. goodei females. These results indicate that both asymmetric postzygotic isolation and the traditional sex-specific costs to preference likely affect the nature of selection on conspecific preferences and target traits.
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Affiliation(s)
- Michelle E St John
- School of Integrative Biology, University of Illinois Urbana-Champaign, Champaign, IL 61820, USA
| | - Rebecca C Fuller
- School of Integrative Biology, University of Illinois Urbana-Champaign, Champaign, IL 61820, USA
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10
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Reid BN, Moran RL, Kopack CJ, Fitzpatrick SW. Rapture-ready darters: Choice of reference genome and genotyping method (whole-genome or sequence capture) influence population genomic inference in Etheostoma. Mol Ecol Resour 2020; 21:404-420. [PMID: 33058399 DOI: 10.1111/1755-0998.13275] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/17/2020] [Accepted: 10/01/2020] [Indexed: 11/26/2022]
Abstract
Researchers studying nonmodel organisms have an increasing number of methods available for generating genomic data. However, the applicability of different methods across species, as well as the effect of reference genome choice on population genomic inference, remain difficult to predict in many cases. We evaluated the impact of data type (whole-genome vs. reduced representation) and reference genome choice on data quality and on population genomic and phylogenomic inference across several species of darters (subfamily Etheostomatinae), a highly diverse radiation of freshwater fish. We generated a high-quality reference genome and developed a hybrid RADseq/sequence capture (Rapture) protocol for the Arkansas darter (Etheostoma cragini). Rapture data from 1,900 individuals spanning four darter species showed recovery of most loci across darter species at high depth and consistent estimates of heterozygosity regardless of reference genome choice. Loci with baits spanning both sides of the restriction enzyme cut site performed especially well across species. For low-coverage whole-genome data, choice of reference genome affected read depth and inferred heterozygosity. For similar amounts of sequence data, Rapture performed better at identifying fine-scale genetic structure compared to whole-genome sequencing. Rapture loci also recovered an accurate phylogeny for the study species and demonstrated high phylogenetic informativeness across the evolutionary history of the genus Etheostoma. Low cost and high cross-species effectiveness regardless of reference genome suggest that Rapture and similar sequence capture methods may be worthwhile choices for studies of diverse species radiations.
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Affiliation(s)
- Brendan N Reid
- Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA
| | - Rachel L Moran
- Department of Evolution, Ecology, and Behavior, University of Minnesota, Saint Paul, MN, USA
| | | | - Sarah W Fitzpatrick
- Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA.,Department of Integrative Biology, Michigan State University, East Lansing, MI, USA
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11
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Ohsaki N, Ohata M, Sato Y, Rausher MD. Host Plant Choice Determined by Reproductive Interference between Closely Related Butterflies. Am Nat 2020; 196:512-523. [PMID: 32970464 DOI: 10.1086/710211] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractA number of empirical studies have concluded that reproductive interference (RI) contributes to parapatric species distributions or sexual exclusion. However, the possibility that divergent host plant use in phytophagous insects is due to sexual exclusion has seldom been considered. Here, we present evidence that RI is responsible for different host plant use by two Pierid butterfly species, Pieris napi and Pieris melete. When a novel host species was introduced about 50 years ago, two Pierid butterfly species at first used both the ancestral host species and the novel one. Subsequently, P. napi shifted to use only the novel host, while P. melete shifted to specialize on the ancestral host. To explain these patterns, we investigated whether the two host species differ in suitability for larval growth and survival. Additionally, we tested whether RI occurred between the two butterfly species using large outdoor field cages. Courtship of females by conspecific and heterospecific males reduces the number of eggs laid by approximately half. However, RI is asymmetric and would generate selection on P. melete females to evolve to avoid the more suitable host species preferred by P. napi. Thus, our study suggests that sexual exclusion can explain the shift in host plant use by these two butterfly species.
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12
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Mattson CL, Roberts NS, Mendelson TC. Male preference for conspecific females depends on male size in the splendid darter, Etheostoma barrenense. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.04.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Drury JP, Cowen MC, Grether GF. Competition and hybridization drive interspecific territoriality in birds. Proc Natl Acad Sci U S A 2020; 117:12923-12930. [PMID: 32457140 PMCID: PMC7293658 DOI: 10.1073/pnas.1921380117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Costly interactions between species that arise as a by-product of ancestral similarities in communication signals are expected to persist only under specific evolutionary circumstances. Territorial aggression between species, for instance, is widely assumed to persist only when extrinsic barriers prevent niche divergence or selection in sympatry is too weak to overcome gene flow from allopatry. However, recent theoretical and comparative studies have challenged this view. Here we present a large-scale, phylogenetic analysis of the distribution and determinants of interspecific territoriality. We find that interspecific territoriality is widespread in birds and strongly associated with hybridization and resource overlap during the breeding season. Contrary to the view that territoriality only persists between species that rarely breed in the same areas or where niche divergence is constrained by habitat structure, we find that interspecific territoriality is positively associated with breeding habitat overlap and unrelated to habitat structure. Furthermore, our results provide compelling evidence that ancestral similarities in territorial signals are maintained and reinforced by selection when interspecific territoriality is adaptive. The territorial signals linked to interspecific territoriality in birds depend on the evolutionary age of interacting species, plumage at shallow (within-family) timescales, and song at deeper (between-family) timescales. Evidently, territorial interactions between species have persisted and shaped phenotypic diversity on a macroevolutionary timescale.
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Affiliation(s)
- Jonathan P Drury
- Department of Biosciences, Durham University, DH1 3LE Durham, United Kingdom;
| | - Madeline C Cowen
- Department of Ecology & Evolutionary Biology, University of California, Los Angeles, CA 90095
| | - Gregory F Grether
- Department of Ecology & Evolutionary Biology, University of California, Los Angeles, CA 90095
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14
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Roberts NS, Mendelson TC. Reinforcement in the banded darter Etheostoma zonale: The effect of sex and sympatry on preferences. Ecol Evol 2020; 10:2499-2512. [PMID: 32184997 PMCID: PMC7069321 DOI: 10.1002/ece3.6076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/11/2019] [Accepted: 01/07/2020] [Indexed: 11/10/2022] Open
Abstract
Reinforcement occurs when selection against hybrid offspring strengthens behavioral isolation between parental species and may be an important factor in speciation. Theoretical models and experimental evidence indicate that both female and male preferences can be strengthened upon secondary contact via reinforcement. However, the question remains whether this process is more likely to affect the preferences of one sex or the other. Males of polygynous species are often predicted to exhibit weaker preferences than females, potentially limiting the ability for reinforcement to shape male preferences. Yet, in darters (Percidae: Etheostoma), male preference for conspecific mates appears to arise before female preferences during the early stages of allopatric speciation, and research suggests that male, but not female, preferences become reinforced upon secondary contact. In the current study, we aimed to determine whether the geographically widespread darter species Etheostoma zonale exhibits a signature of reinforcement, by comparing the strength of preference for conspecific mates between populations that are sympatric and allopatric with respect to a close congener, E. barrenense. We examined the strength of preference for conspecifics for males and females separately to determine whether the preferences of one or both sexes have been strengthened by reinforcement. Our results show that both sexes of E. zonale from sympatric populations exhibit stronger conspecific preferences than E. zonale from allopatric populations, but that female preferences appear to be more strongly reinforced than male preferences. Results therefore suggest that reinforcement of female preferences may promote behavioral isolation upon secondary contact, even in a genus that is characterized by pervasive male mate choice.
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Affiliation(s)
- Natalie S. Roberts
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMDUSA
| | - Tamra C. Mendelson
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMDUSA
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15
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Moran RL, Catchen JM, Fuller RC. Genomic Resources for Darters (Percidae: Etheostominae) Provide Insight into Postzygotic Barriers Implicated in Speciation. Mol Biol Evol 2020; 37:711-729. [PMID: 31688927 PMCID: PMC7038671 DOI: 10.1093/molbev/msz260] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Comparative genomic approaches are increasingly being used to study the evolution of reproductive barriers in nonmodel species. Although numerous studies have examined prezygotic isolation in darters (Percidae), investigations into postzygotic barriers have remained rare due to long generation times and a lack of genomic resources. Orangethroat and rainbow darters naturally hybridize and provide a remarkable example of male-driven speciation via character displacement. Backcross hybrids suffer from high mortality, which appears to promote behavioral isolation in sympatry. To investigate the genomic architecture of postzygotic isolation, we used Illumina and PacBio sequencing to generate a chromosome-level, annotated assembly of the orangethroat darter genome and high-density linkage maps for orangethroat and rainbow darters. We also analyzed genome-wide RADseq data from wild-caught adults of both species and laboratory-generated backcrosses to identify genomic regions associated with hybrid incompatibles. Several putative chromosomal translocations and inversions were observed between orangethroat and rainbow darters, suggesting structural rearrangements may underlie postzygotic isolation. We also found evidence of selection against recombinant haplotypes and transmission ratio distortion in backcross hybrid genomes, providing further insight into the genomic architecture of genetic incompatibilities. Notably, regions with high levels of genetic divergence between species were enriched for genes associated with developmental and meiotic processes, providing strong candidates for postzygotic isolating barriers. These findings mark significant contributions to our understanding of the genetic basis of reproductive isolation between species undergoing character displacement. Furthermore, the genomic resources presented here will be instrumental for studying speciation in darters, the most diverse vertebrate group in North America.
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Affiliation(s)
- Rachel L Moran
- Program in Ecology, Evolution, and Conservation Biology, Department of Animal Biology, University of Illinois at Urbana-Champaign, Champaign, IL
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN
| | - Julian M Catchen
- Program in Ecology, Evolution, and Conservation Biology, Department of Animal Biology, University of Illinois at Urbana-Champaign, Champaign, IL
| | - Rebecca C Fuller
- Program in Ecology, Evolution, and Conservation Biology, Department of Animal Biology, University of Illinois at Urbana-Champaign, Champaign, IL
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16
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Grether GF, Drury JP, Okamoto KW, McEachin S, Anderson CN. Predicting evolutionary responses to interspecific interference in the wild. Ecol Lett 2019; 23:221-230. [PMID: 31733032 DOI: 10.1111/ele.13395] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/27/2019] [Accepted: 09/07/2019] [Indexed: 11/27/2022]
Abstract
Many interspecifically territorial species interfere with each other reproductively, and in some cases, aggression towards heterospecifics may be an adaptive response to interspecific mate competition. This hypothesis was recently formalised in an agonistic character displacement (ACD) model which predicts that species should evolve to defend territories against heterospecific rivals above a threshold level of reproductive interference. To test this prediction, we parameterised the model with field estimates of reproductive interference for 32 sympatric damselfly populations and ran evolutionary simulations. Asymmetries in reproductive interference made the outcome inherently unpredictable in some cases, but 80% of the model's stable outcomes matched levels of heterospecific aggression in the field, significantly exceeding chance expectations. In addition to bolstering the evidence for ACD, this paper introduces a new, predictive approach to testing character displacement theory that, if applied to other systems, could help in resolving long-standing questions about the importance of character displacement processes in nature.
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Affiliation(s)
- Gregory F Grether
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, USA
| | | | | | - Shawn McEachin
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, USA
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17
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Johnson AM, Chang CH, Fuller RC. Testing the potential mechanisms for the maintenance of a genetic color polymorphism in bluefin killifish populations. Curr Zool 2018; 64:733-743. [PMID: 30538733 PMCID: PMC6280095 DOI: 10.1093/cz/zoy017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 02/28/2018] [Indexed: 02/03/2023] Open
Abstract
The maintenance of genetic variation in the face of natural selection is a long-standing question in evolutionary biology. In the bluefin killifish Lucania goodei, male coloration is polymorphic. Males can produce either red or yellow coloration in their anal fins, and both color morphs are present in all springs. These 2 morphs are heritable and how they are maintained in nature is unknown. Here, we tested 2 mechanisms for the maintenance of the red/yellow color morphs. Negative frequency-dependent mating success predicts that rare males have a mating advantage over common males. Spatial variation in fitness predicts that different color morphs have an advantage in different microhabitat types. Using a breeding experiment, we tested these hypotheses by creating populations with different ratios of red to yellow males (5 red:1 yellow; 1 red:5 yellow) and determining male mating success on shallow and deep spawning substrates. We found no evidence of negative frequency-dependent mating success. Common morphs tended to have higher mating success, and this was particularly so on shallow spawning substrates. However, on deep substrates, red males enjoyed higher mating success than yellow males, particularly so when red males were rare. However, yellow males did not have an advantage at either depth nor when rare. We suggest that preference for red males is expressed in deeper water, possibly due to alterations in the lighting environment. Finally, male pigment levels were correlated with one another and predicted male mating success. Hence, pigmentation plays an important role in male mating success.
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Affiliation(s)
- Ashley M Johnson
- Department of Animal Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Chia-Hao Chang
- Department of Animal Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Rebecca C Fuller
- Department of Animal Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
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18
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Moran RL, Zhou M, Catchen JM, Fuller RC. Hybridization and postzygotic isolation promote reinforcement of male mating preferences in a diverse group of fishes with traditional sex roles. Ecol Evol 2018; 8:9282-9294. [PMID: 30377500 PMCID: PMC6194240 DOI: 10.1002/ece3.4434] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/11/2018] [Accepted: 07/12/2018] [Indexed: 02/05/2023] Open
Abstract
Behavioral isolation is thought to arise early in speciation due to differential sexual and/or natural selection favoring different preferences and traits in different lineages. Instead, behavioral isolation can arise due to reinforcement favoring traits and preferences that prevent maladaptive hybridization. In darters, female preference for male coloration has been hypothesized to drive speciation, because behavioral isolation evolves before F1 inviability. However, as with many long-lived organisms, the fitness of second-generation hybrids has not been assessed because raising animals to adulthood in the laboratory is challenging. Of late, reinforcement of male preferences has been implicated in darters because male preference for conspecific females is high in sympatry but absent in allopatry in multiple species pairs. The hypothesis that reinforcement accounts for behavioral isolation in sympatry assumes that hybridization and postzygotic isolation are present. Here, we used genomic and morphological data to demonstrate that hybridization is ongoing between orangethroat and rainbow darters and used hybrids collected from nature to measure postzygotic barriers across two hybrid generations. We observed sex ratio distortion in adult F1s and a dramatic reduction in backcross survival. Our findings indicate that selection to avoid hybridization promotes the evolution of male-driven behavioral isolation via reinforcement in this system.
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Affiliation(s)
- Rachel L. Moran
- Program in Ecology, Evolution, and Conservation BiologyUniversity of Illinois at Urbana‐ChampaignChampaignIllinois
- Department of Animal BiologyUniversity of Illinois at Urbana‐ChampaignChampaignIllinois
| | - Muchu Zhou
- Program in Ecology, Evolution, and Conservation BiologyUniversity of Illinois at Urbana‐ChampaignChampaignIllinois
- Department of Animal BiologyUniversity of Illinois at Urbana‐ChampaignChampaignIllinois
| | - Julian M. Catchen
- Program in Ecology, Evolution, and Conservation BiologyUniversity of Illinois at Urbana‐ChampaignChampaignIllinois
- Department of Animal BiologyUniversity of Illinois at Urbana‐ChampaignChampaignIllinois
| | - Rebecca C. Fuller
- Program in Ecology, Evolution, and Conservation BiologyUniversity of Illinois at Urbana‐ChampaignChampaignIllinois
- Department of Animal BiologyUniversity of Illinois at Urbana‐ChampaignChampaignIllinois
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19
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Moran RL, Fuller RC. Agonistic character displacement of genetically based male colour patterns across darters. Proc Biol Sci 2018; 285:20181248. [PMID: 30068684 PMCID: PMC6111152 DOI: 10.1098/rspb.2018.1248] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 07/10/2018] [Indexed: 11/12/2022] Open
Abstract
Agonistic character displacement (ACD) occurs when selection to avoid maladaptive interspecific aggression leads to the evolution of agonistic signals and/or associated behavioural biases in sympatry. Here, we test for a pattern consistent with ACD in male colour pattern in darters (Percidae: Etheostoma). Male colour pattern has been shown to function in male-male competition rather than female mating preferences in several darter species. Additionally, males bias their aggression towards conspecific over heterospecific males in sympatry but not in allopatry, consistent with divergent ACD in male behavioural biases. We use a common garden approach to show that differences in male colour pattern among four closely related darter species are genetically based. Additionally, we demonstrate that some aspects of male colour pattern exhibit enhanced differences in sympatric compared to allopatric populations of two darter species, consistent with ACD. However, other male colour traits are more similar between species in sympatry compared with allopatry, indicating that not all signal components are under strong divergent selection in sympatry. This study provides evidence that interspecific male-male aggressive interactions alone can promote elaborate male signal evolution both between and within species. We discuss the implications this has for male-driven ACD and cascade ACD.
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Affiliation(s)
- Rachel L Moran
- Program in Ecology, Evolution, and Conservation Biology, Department of Animal Biology, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA
| | - Rebecca C Fuller
- Program in Ecology, Evolution, and Conservation Biology, Department of Animal Biology, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA
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20
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Lackey ACR, Martin MD, Tinghitella RM. Male competition and speciation: expanding our framework for speciation by sexual selection. Curr Zool 2018; 64:69-73. [PMID: 29492040 PMCID: PMC5809040 DOI: 10.1093/cz/zoy009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Alycia C R Lackey
- Department of Biological Sciences, Binghamton University, Binghamton, NY 13902, USA
| | - Michael D Martin
- Department of Biology, Oxford College of Emory University, Oxford, GA 30054, USA
| | - Robin M Tinghitella
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA
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