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Colwell RK, Rangel TF, Fučíková K, Sustaita D, Yanega GM, Rico-Guevara A. Repeated Evolution of Unorthodox Feeding Styles Drives a Negative Correlation between Foot Size and Bill Length in Hummingbirds. Am Nat 2023; 202:699-720. [PMID: 37963119 DOI: 10.1086/726036] [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: 11/16/2023]
Abstract
AbstractDifferences among hummingbird species in bill length and shape have rightly been viewed as adaptive in relation to the morphology of the flowers they visit for nectar. In this study we examine functional variation in a behaviorally related but neglected feature: hummingbird feet. We gathered records of hummingbirds clinging by their feet to feed legitimately as pollinators or illegitimately as nectar robbers-"unorthodox" feeding behaviors. We measured key features of bills and feet for 220 species of hummingbirds and compared the 66 known "clinger" species (covering virtually the entire scope of hummingbird body size) with the 144 presumed "non-clinger" species. Once the effects of phylogenetic signal, body size, and elevation above sea level are accounted for statistically, hummingbirds display a surprising but functionally interpretable negative correlation. Clingers with short bills and long hallux (hind-toe) claws have evolved-independently-more than 20 times and in every major clade. Their biomechanically enhanced feet allow them to save energy by clinging to feed legitimately on short-corolla flowers and by stealing nectar from long-corolla flowers. In contrast, long-billed species have shorter hallux claws, as plant species with long-corolla flowers enforce hovering to feed, simply by the way they present their flowers.
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2
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Razzaque S, Heckman RW, Juenger TE. Seed size variation impacts local adaptation and life-history strategies in a perennial grass. Proc Biol Sci 2023; 290:20222460. [PMID: 37132240 PMCID: PMC10154936 DOI: 10.1098/rspb.2022.2460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 04/03/2023] [Indexed: 05/04/2023] Open
Abstract
Seed mass is an ecologically important trait that often differs considerably among ecotypes. Yet, because few studies examine the impacts of seed mass on adult life-history traits, its role in local adaptation is unclear. In this study, using accessions of Panicum hallii that spanned the two major ecotypes, we examined whether covariation between seed mass, seedling and reproductive traits impacts ecotypic divergence and local adaptation. The perennial grass P. hallii has two distinct ecotypes-a large-seeded upland ecotype adapted to xeric environments and a small-seeded lowland ecotype adapted to mesic environments. In the greenhouse, seed mass varied greatly across P. hallii genotypes in a manner consistent with ecotypic divergence. Seed mass covaried significantly with several seedling and reproductive traits. At field sites representing the habitats of the two ecotypes, seed mass had different impacts on seedling and adult recruitment: selection favoured large seeds in upland habitat and small seeds in lowland habitat, which was consistent with local adaptation. By demonstrating the central role of seed mass in ecotypic differences in P. hallii and its importance to seedling and adult recruitment under field conditions, these studies show that early life-history traits can promote local adaptation and potentially explain ecotype formation.
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Affiliation(s)
- Samsad Razzaque
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Robert W. Heckman
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Thomas E. Juenger
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
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3
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Liu C, Kenney T, Beiko RG, Gu H. The Community Coevolution Model with Application to the Study of Evolutionary Relationships between Genes based on Phylogenetic Profiles. Syst Biol 2022:6651862. [PMID: 35904761 DOI: 10.1093/sysbio/syac052] [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: 10/05/2021] [Revised: 07/15/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Organismal traits can evolve in a coordinated way, with correlated patterns of gains and losses reflecting important evolutionary associations. Discovering these associations can reveal important information about the functional and ecological linkages among traits. Phylogenetic profiles treat individual genes as traits distributed across sets of genomes and can provide a fine-grained view of the genetic underpinnings of evolutionary processes in a set of genomes. Phylogenetic profiling has been used to identify genes that are functionally linked, and to identify common patterns of lateral gene transfer in microorganisms. However, comparative analysis of phylogenetic profiles and other trait distributions should take into account the phylogenetic relationships among the organisms under consideration. Here we propose the Community Coevolution Model (CCM), a new coevolutionary model to analyze the evolutionary associations among traits, with a focus on phylogenetic profiles. In the CCM, traits are considered to evolve as a community with interactions, and the transition rate for each trait depends on the current states of other traits. Surpassing other comparative methods for pairwise trait analysis, CCM has the additional advantage of being able to examine multiple traits as a community to reveal more dependency relationships. We also develop a simulation procedure to generate phylogenetic profiles with correlated evolutionary patterns that can be used as benchmark data for evaluation purposes. A simulation study demonstrates that CCM is more accurate than other methods including the Jaccard Index and three tree-aware methods. The parameterization of CCM makes the interpretation of the relations between genes more direct, which leads to Darwin's scenario being identified easily based on the estimated parameters. We show that CCM is more efficient and fits real data better than other methods resulting in higher likelihood scores with fewer parameters. An examination of 3786 phylogenetic profiles across a set of 659 bacterial genomes highlights linkages between genes with common functions, including many patterns that would not have been identified under a non-phylogenetic model of common distribution. We also applied the CCM to 44 proteins in the well-studied Mitochondrial Respiratory Complex I and recovered associations that mapped well onto the structural associations that exist in the complex.
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Affiliation(s)
- Chaoyue Liu
- Department of Mathematics and Statistics, Dalhousie University, Halifax, B3H 4R2, Canada.,Faculty of Computer Science, Dalhousie University, Halifax, B3H 4R2, Canada
| | - Toby Kenney
- Department of Mathematics and Statistics, Dalhousie University, Halifax, B3H 4R2, Canada
| | - Robert G Beiko
- Faculty of Computer Science, Dalhousie University, Halifax, B3H 4R2, Canada
| | - Hong Gu
- Department of Mathematics and Statistics, Dalhousie University, Halifax, B3H 4R2, Canada
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4
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Custer GF, Bresciani L, Dini-Andreote F. Ecological and Evolutionary Implications of Microbial Dispersal. Front Microbiol 2022; 13:855859. [PMID: 35464980 PMCID: PMC9019484 DOI: 10.3389/fmicb.2022.855859] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 03/14/2022] [Indexed: 12/04/2022] Open
Abstract
Dispersal is simply defined as the movement of species across space and time. Despite this terse definition, dispersal is an essential process with direct ecological and evolutionary implications that modulate community assembly and turnover. Seminal ecological studies have shown that environmental context (e.g., local edaphic properties, resident community), dispersal timing and frequency, and species traits, collectively account for patterns of species distribution resulting in either their persistence or unsuccessful establishment within local communities. Despite the key importance of this process, relatively little is known about how dispersal operates in microbiomes across divergent systems and community types. Here, we discuss parallels of macro- and micro-organismal ecology with a focus on idiosyncrasies that may lead to novel mechanisms by which dispersal affects the structure and function of microbiomes. Within the context of ecological implications, we revise the importance of short- and long-distance microbial dispersal through active and passive mechanisms, species traits, and community coalescence, and how these align with recent advances in metacommunity theory. Conversely, we enumerate how microbial dispersal can affect diversification rates of species by promoting gene influxes within local communities and/or shifting genes and allele frequencies via migration or de novo changes (e.g., horizontal gene transfer). Finally, we synthesize how observed microbial assemblages are the dynamic outcome of both successful and unsuccessful dispersal events of taxa and discuss these concepts in line with the literature, thus enabling a richer appreciation of this process in microbiome research.
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Affiliation(s)
- Gordon F Custer
- Department of Plant Science and Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, United States
| | - Luana Bresciani
- Department of Plant Science and Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, United States
| | - Francisco Dini-Andreote
- Department of Plant Science and Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, United States
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5
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Abstract
The integration of life-history, behavioural and physiological traits into a ‘pace-of-life syndrome’ is a powerful concept in understanding trait variation in nature. Yet, mechanisms maintaining variation in ‘pace-of-life’ are not well understood. We tested whether decreased thermal performance is an energetic cost of a faster pace-of-life. We characterized the pace-of-life of larvae of the damselfly Ischnura elegans from high-latitude and low-latitude regions when reared at 20°C or 24°C in a common-garden experiment, and estimated thermal performance curves for a set of behavioural, physiological and performance traits. Our results confirm a faster pace-of-life (i.e. faster growth and metabolic rate, more active and bold behaviour) in the low-latitude and in warm-reared larvae, and reveal increased maximum performance, Rmax, but not thermal optimum Topt, in low-latitude larvae. Besides a clear pace-of-life syndrome integration at the individual level, larvae also aligned along a ‘cold–hot’ axis. Importantly, a faster pace-of-life correlated negatively with a high thermal performance (i.e. higher Topt for swimming speed, metabolic rate, activity and boldness), which was consistent across latitudes and rearing temperatures. This trade-off, potentially driven by the energetically costly maintenance of a fast pace-of-life, may be an alternative mechanism contributing to the maintenance of variation in pace-of-life within populations.
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Affiliation(s)
- Nedim Tüzün
- Laboratory of Evolutionary Stress Ecology and Ecotoxicology, KU Leuven, Charles Deberiotstraat 32, 3000 Leuven, Belgium
| | - Robby Stoks
- Laboratory of Evolutionary Stress Ecology and Ecotoxicology, KU Leuven, Charles Deberiotstraat 32, 3000 Leuven, Belgium
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de Pedro M, Mayol M, González-Martínez SC, Regalado I, Riba M. Environmental patterns of adaptation after range expansion in Leontodon longirostris: The effect of phenological events on fitness-related traits. AMERICAN JOURNAL OF BOTANY 2022; 109:602-615. [PMID: 35067917 DOI: 10.1002/ajb2.1815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 12/27/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
PREMISE Because of expected range shifts associated with climate change, there is a renewed interest in the evolutionary factors constraining adaptation, among which are genetic bottlenecks, drift, and increased mutational load after range expansion. Here we study adaptation in the short-lived species Leontodon longirostris showing reduced genetic diversity and increased genetic load along an expansion route. METHODS We assessed the phenological patterns of variation, and their effect on fitness-related traits, on 42 L. longirostris populations and six populations of the sister taxa L. saxatilis in a common garden located within the current range of both species. The comparison among L. longirostris populations allowed us to test for genetic clines consistent with local adaptation, whereas the comparison between taxa provided evidence for common adaptive features at the species level. RESULTS We found significant within-species variability for most traits, as well as differences with its close relative L. saxatilis. In general, seeds from drier, warmer, and unpredictable habitats showed overall lower and more restricted conditions for germination, seedlings emerged later and plants flowered earlier. Consequently, genotypes from arid and unpredictable environments attained smaller reproductive sizes and allocated more biomass to reproduction. Flowering time had the strongest direct effect on total plant size, but seedling emergence also showed an important indirect effect. CONCLUSIONS Our results show the crucial role of phenological patterns in shaping adaptive clines for major life-history stage transitions. Furthermore, the genetic load observed in L. longirostris does not seem to preclude adaptation to the climatic variability encountered along the expansion route.
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Affiliation(s)
| | - Maria Mayol
- CREAF, Cerdanyola del Vallès 08193, Spain
- Univ. Autònoma Barcelona, Cerdanyola del Vallès 08193, Spain
| | | | | | - Miquel Riba
- CREAF, Cerdanyola del Vallès 08193, Spain
- Univ. Autònoma Barcelona, Cerdanyola del Vallès 08193, Spain
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He D. Leaf economic strategies of a sclerophyllous plant (Eurya japonica): commonalities and particularities of trait correlation structures in low-moisture and low-phosphorus habitats. FUNCTIONAL PLANT BIOLOGY : FPB 2021; 48:1017-1028. [PMID: 34266540 DOI: 10.1071/fp21119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 06/07/2021] [Indexed: 06/13/2023]
Abstract
Sclerophylly proves an advantageous strategy in a variety of stressful environments. However, it is less clear how multiple phenotypic traits in sclerophyllous plants are integrated to accomplish proper functions under specific stressors. This study measured 10 leaf traits in a sclerophyllous species, Eurya japonica Thunb., in the Zhoushan Archipelago, eastern China, to examine how the structures of trait correlation (i.e. phenotypic integration) vary between two habitats with contrasting moisture and phosphorus (P) availability. Overall, the trait correlation matrices were similar between the two habitats under study (Mantel r > 0.5), reflecting a consistent trade-off between leaf outspreading (i.e. leaf area/mass ratio) and water-use efficiency (measured by δ13C). Stomatal conductance was correlated with leaf area, thickness and area/mass ratio only in the dry, P-rich habitat, whereas it was robustly correlated with leaf P per unit area in the wet, P-poor habitat. Moreover, leaf water-use efficiency was robustly correlated with leaf P and N per unit area in the dry habitat, but not so in the low-P one. These differences in trait correlation structures illustrate that the pathways of strategic compromise under contrasting stressors were locally specialised. This study highlights the importance of phenotypic integration as an emergent 'trait' in sustaining viable strategies.
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Affiliation(s)
- Dong He
- Putuo Island Ecosystem Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China.
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8
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Matesanz S, Blanco-Sánchez M, Ramos-Muñoz M, de la Cruz M, Benavides R, Escudero A. Phenotypic integration does not constrain phenotypic plasticity: differential plasticity of traits is associated to their integration across environments. THE NEW PHYTOLOGIST 2021; 231:2359-2370. [PMID: 34097309 DOI: 10.1111/nph.17536] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 05/25/2021] [Indexed: 06/12/2023]
Abstract
Understanding constraints to phenotypic plasticity is key given its role on the response of organisms to environmental change. It has been suggested that phenotypic integration, the structure of trait covariation, could limit trait plasticity. However, the relationship between plasticity and integration is far from resolved. Using a database of functional plasticity to drought of a Mediterranean shrub that included 20 ecophysiological traits, we assessed environmentally-induced changes in phenotypic integration and whether integration constrained the expression of plasticity, accounting for the within-environment phenotypic variation of traits. Furthermore, we provide the first test of the association between differential trait plasticity and trait integration across an optimum and a stressful environment. Phenotypic plasticity was positively associated with phenotypic integration in both environments, but this relationship was lost when phenotypic variation was considered. The similarity in the plastic response of two traits predicted their integration across environments, with integrated traits having more similar plasticity. Such variation in the plasticity of traits partly explained the lower phenotypic integration found in the stressful environment. We found no evidence that integration may constitute an internal constraint to plasticity. Rather, we present the first empirical demonstration that differences in plastic responses may involve a major reorganization of the relationships among traits, and challenge the notion that stress generally induces a tighter phenotype.
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Affiliation(s)
- Silvia Matesanz
- Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, C/Tulipán, s/n, Móstoles, 28933, Spain
| | - Mario Blanco-Sánchez
- Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, C/Tulipán, s/n, Móstoles, 28933, Spain
| | - Marina Ramos-Muñoz
- Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, C/Tulipán, s/n, Móstoles, 28933, Spain
| | - Marcelino de la Cruz
- Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, C/Tulipán, s/n, Móstoles, 28933, Spain
| | - Raquel Benavides
- Centro de Estudos Florestais, ISA, Universidade de Lisboa, Tapada da Ajuda, Lisboa, 1349-017, Portugal
- Departamento de Biogeografía y Cambio Global, Museo Nacional de Ciencias Naturales, CSIC, C/José Gutiérrez Abascal 2, Madrid, 28006, Spain
| | - Adrián Escudero
- Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, C/Tulipán, s/n, Móstoles, 28933, Spain
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9
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Hahn PG, Keefover‐Ring K, Nguyen LMN, Maron JL. Intraspecific correlations between growth and defence vary with resource availability and differ within and among populations. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13878] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Philip G. Hahn
- Entomology and Nematology Department University of Florida Gainesville FL USA
| | - Ken Keefover‐Ring
- Department of Botany University of Wisconsin‐Madison Madison WI USA
- Department of Geography University of Wisconsin‐Madison Madison WI USA
| | | | - John L. Maron
- Division of Biological Sciences University of Montana Missoula MT USA
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10
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Perkovich C, Ward D. Herbivore-induced defenses are not under phylogenetic constraints in the genus Quercus (oak): Phylogenetic patterns of growth, defense, and storage. Ecol Evol 2021; 11:5187-5203. [PMID: 34026000 PMCID: PMC8131805 DOI: 10.1002/ece3.7409] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/05/2021] [Accepted: 02/12/2021] [Indexed: 11/30/2022] Open
Abstract
The evolution of plant defenses is often constrained by phylogeny. Many of the differences between competing plant defense theories hinge upon the differences in the location of meristem damage (apical versus auxiliary) and the amount of tissue removed. We analyzed the growth and defense responses of 12 Quercus (oak) species from a well-resolved molecular phylogeny using phylogenetically independent contrasts. Access to light is paramount for forest-dwelling tree species, such as many members of the genus Quercus. We therefore predicted a greater investment in defense when apical meristem tissue was removed. We also predicted a greater investment in defense when large amounts of tissue were removed and a greater investment in growth when less tissues were removed. We conducted five simulated herbivory treatments including a control with no damage and alterations of the location of meristem damage (apical versus auxiliary shoots) and intensity (25% versus 75% tissue removal). We measured growth, defense, and nutrient re-allocation traits in response to simulated herbivory. Phylomorphospace models were used to demonstrate the phylogenetic nature of trade-offs between characteristics of growth, chemical defenses, and nutrient re-allocation. We found that growth-defense trade-offs in control treatments were under phylogenetic constraints, but phylogenetic constraints and growth-defense trade-offs were not common in the simulated herbivory treatments. Growth-defense constraints exist within the Quercus genus, although there are adaptations to herbivory that vary among species.
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Affiliation(s)
| | - David Ward
- Department of Biological SciencesKent State UniversityKentOHUSA
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11
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Axelrod CJ, Laberge F, Robinson BW. Interspecific and intraspecific comparisons reveal the importance of evolutionary context in sunfish brain form divergence. J Evol Biol 2021; 34:639-652. [PMID: 33484022 DOI: 10.1111/jeb.13763] [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: 08/18/2020] [Revised: 12/23/2020] [Accepted: 01/11/2021] [Indexed: 01/03/2023]
Abstract
Habitats can select for specialized phenotypic characteristics in animals. However, the consistency of evolutionary responses to particular environmental conditions remains difficult to predict. One trait of great ecological importance is brain form, which is expected to vary between habitats that differ in their cognitive requirements. Here, we compared divergence in brain form and oral jaw size across a common littoral-pelagic ecological axis in two sunfishes at both the intraspecific and interspecific levels. Brain form differed between habitats at every level of comparison; however, divergence was inconsistent, despite consistent differences in oral jaw size. Pumpkinseed and bluegill species differed in cerebellum, optic tectum and olfactory bulb size. These differences are consistent with a historical ecological divergence because they did not manifest between littoral and pelagic ecotypes within either species, suggesting constraints on changes to these regions over short evolutionary time scales. There were also differences in brain form between conspecific ecotypes, but they were inconsistent between species. Littoral pumpkinseed had larger brains than their pelagic counterpart, and littoral bluegill had smaller telencephalons than their pelagic counterpart. Inconsistent brain form divergence between conspecific ecotypes of pumpkinseed and bluegill sharing a common littoral-pelagic habitat axis suggests that contemporary ecological conditions and historic evolutionary context interact to influence evolutionary changes in brain form in fishes.
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Affiliation(s)
- Caleb J Axelrod
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Frédéric Laberge
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Beren W Robinson
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
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12
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Zerulla TC, Stoddard PK. The Biology of Polymorphic Melanic Side-Spotting Patterns in Poeciliid Fishes. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2020.608289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Melanin-based color patterns are an emerging model for studying molecular and evolutionary mechanisms driving phenotypic correlations. Extensive literature exists on color patterns and their correlated traits in the family Poeciliidae, indicating that these fishes are tractable models. We review the biology of polymorphic melanic side-spotting patterns characterized by macromelanophores forming irregular spotted patterns across fishes’ flanks. These patterns are present in the generaGambusia, Limia, Phalloceros, Poecilia, andXiphophorus. Their presence is controlled by dominant genes on autosomes or sex chromosomes. Variation in expression is under polygenic control; however, these genes’ identities are still largely unknown. In someGambusia holbrookiandPoecilia latipinna, expression is dependent on low temperature exposure, but underlying molecular mechanisms are unknown. Spotted fish develop melanoma in rare cases and are a well-developed model for melanoma research. Little is known about other physiological correlates except that spottedG. holbrookimales exhibit higher basal cortisol levels than unspotted males and that metabolic rate does not differ between morphs in someXiphophorusspecies. Behavioral differences between morphs are widespread, but specific to population, species, and social context. SpottedG. holbrookimales appear to be more social and more dominant. Juvenile spottedG. holbrookihave lower behavioral flexibility, and spottedX. variatusexhibit greater stress resistance. Findings conflict on whether morphs differ in sexual behavior and in sexual selection by females. Melanic side-spotting patterns are uncommon (<30%) in populations, although extreme high-frequency populations exist. This low frequency is surprising for dominant genes, indicating that a variety of selective pressures influence both these patterns and their correlated traits. Little is known about reproductive life history traits. SpottedG. holbrookiare larger and have higher survival when uncommon, but underlying mechanisms remain unknown. Spotted morphs appear to have a strong selective advantage during predation. Predators prefer to attack and consume unspotted morphs; however, this preference disappears when spottedG. holbrookimales are common, indicating negative frequency-dependent selection. Spotted morphs are preferred socially under turbid conditions, but other environmental factors that shape phenotypic correlations and morph fitness have not been studied. Finally, we present questions for future studies on melanic side-spotting patterns.
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14
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Diaz Pauli B, Edeline E, Evangelista C. Ecosystem consequences of multi-trait response to environmental changes in Japanese medaka, Oryzias latipes. CONSERVATION PHYSIOLOGY 2020; 8:coaa011. [PMID: 32274061 PMCID: PMC7125048 DOI: 10.1093/conphys/coaa011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 01/21/2020] [Accepted: 02/02/2020] [Indexed: 06/01/2023]
Abstract
Intraspecific trait variation has large effects on the ecosystem and is greatly affected by human activities. To date, most studies focused on single-trait analyses, while considering multiple traits is expected to better predict how an individual interacts with its environment. Here, we used a mesocosm experiment with fish Oryzias latipes to test whether individual growth, boldness and functional traits (feeding rate and stoichiometric traits) formed one functional pace-of-life syndrome (POLS). We then tested the effects of among-individual mean and variance of fish functional POLSs within mesocosms on invertebrate community (e.g. zoobenthos and zooplankton abundances) and ecosystem processes (e.g. ecosystem metabolism, algae stock, nutrient concentrations). Stoichiometric traits correlated with somatic growth and behaviours, forming two independent functional POLS (i.e. two major covariance axes). Mean values of the first syndrome were sex- and environment-dependent and were associated with (i) long-term (10 generations; 4 years) selection for small or large body size resulting in contrasting life histories and (ii) short-term (6 weeks) effects of experimental treatments on resource availability (through manipulation of light intensity and interspecific competition). Specifically, females and individuals from populations selected for a small body size presented fast functional POLS with faster growth rate, higher carbon body content and lower boldness. Individuals exposed to low resources (low light and high competition) displayed a slow functional POLS. Higher mesocosm mean and variance values in the second functional POLS (i.e. high feeding rate, high carbon:nitrogen body ratio, low ammonium excretion rate) were associated to decreased prey abundances, but did not affect any of the ecosystem processes. We highlighted the presence of functional multi-trait covariation in medaka, which were affected by sex, long-term selection history and short-term environmental conditions, that ultimately had cascading ecological consequences. We stressed the need for applying this approach to better predict ecosystem response to anthropogenic global changes.
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Affiliation(s)
- Beatriz Diaz Pauli
- Department of Biosciences, Centre for Ecological and Evolutionary Syntheses (CEES), University of Oslo, Blindernveien 31, N-0316 Oslo, Norway
| | - Eric Edeline
- ESE Ecology and Ecosystem Health, INRAE, Agocampus Ouest, 65 rue de Saint-Brieuc 35042 Rennes, France
| | - Charlotte Evangelista
- Department of Biosciences, Centre for Ecological and Evolutionary Syntheses (CEES), University of Oslo, Blindernveien 31, N-0316 Oslo, Norway
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15
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Agrawal AA. A scale‐dependent framework for trade‐offs, syndromes, and specialization in organismal biology. Ecology 2020; 101:e02924. [DOI: 10.1002/ecy.2924] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 09/24/2019] [Accepted: 09/26/2019] [Indexed: 02/02/2023]
Affiliation(s)
- Anurag A. Agrawal
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York 14853 USA
- Department of Entomology Cornell University Ithaca New York 14853 USA
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16
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Abstract
The generation of variation is paramount for the action of natural selection. Although biologists are now moving beyond the idea that random mutation provides the sole source of variation for adaptive evolution, we still assume that variation occurs randomly. In this review, we discuss an alternative view for how phenotypic plasticity, which has become well accepted as a source of phenotypic variation within evolutionary biology, can generate nonrandom variation. Although phenotypic plasticity is often defined as a property of a genotype, we argue that it needs to be considered more explicitly as a property of developmental systems involving more than the genotype. We provide examples of where plasticity could be initiating developmental bias, either through direct active responses to similar stimuli across populations or as the result of programmed variation within developmental systems. Such biased variation can echo past adaptations that reflect the evolutionary history of a lineage but can also serve to initiate evolution when environments change. Such adaptive programs can remain latent for millions of years and allow development to harbor an array of complex adaptations that can initiate new bouts of evolution. Specifically, we address how ideas such as the flexible stem hypothesis and cryptic genetic variation overlap, how modularity among traits can direct the outcomes of plasticity, and how the structure of developmental signaling pathways is limited to a few outcomes. We highlight key questions throughout and conclude by providing suggestions for future research that can address how plasticity initiates and harbors developmental bias.
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Affiliation(s)
- Kevin J. Parsons
- Institute of Biodiversity, Animal Health, and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Kirsty McWhinnie
- Institute of Biodiversity, Animal Health, and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Natalie Pilakouta
- Institute of Biodiversity, Animal Health, and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Lynsey Walker
- Institute of Biodiversity, Animal Health, and Comparative MedicineUniversity of GlasgowGlasgowUK
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Temperature and Rainfall Are Separate Agents of Selection Shaping Population Differentiation in a Forest Tree. FORESTS 2019. [DOI: 10.3390/f10121145] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Research highlights: We present evidence indicating that covariation of functional traits among populations of a forest tree is not due to genetic constraints, but rather selective covariance arising from local adaptation to different facets of the climate, namely rainfall and temperature. Background and Aims: Traits frequently covary among natural populations. Such covariation can be caused by pleiotropy and/or linkage disequilibrium, but also may arise when the traits are genetically independent as a direct consequence of natural selection, drift, mutation and/or gene flow. Of particular interest are cases of selective covariance, where natural selection directly generates among-population covariance in a set of genetically independent traits. We here studied the causes of population-level covariation in two key traits in the Australian tree Eucalyptus pauciflora. Materials and Methods: We studied covariation in seedling lignotuber size and vegetative juvenility using 37 populations sampled from throughout the geographic and ecological ranges of E. pauciflora on the island of Tasmania. We integrated evidence from multiple sources: (i) comparison of patterns of trait covariation within and among populations; (ii) climate-trait modelling using machine-learning algorithms; and (iii) selection analysis linking trait variation to field growth in an arid environment. Results: We showed strong covariation among populations compared with the weak genetic correlation within populations for the focal traits. Population differentiation in these genetically independent traits was correlated with different home-site climate variables (lignotuber size with temperature; vegetative juvenility with rainfall), which spatially covaried. The role of selection in shaping the population differentiation in lignotuber size was supported by its relationship with fitness measured in the field. Conclusions: Our study highlights the multi-trait nature of adaptation likely to occur as tree species respond to spatial and temporal changes in climate.
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Lopes CF, Stefanello F, Bugs C, Stenert C, Maltchik L, Ribeiro JRI. Sexual dimorphism in Belostoma angustum Lauck (Insecta: Heteroptera: Belostomatidae) may be related to paternal care. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
The structures involved in parental care are often dimorphic. Female Belostoma angustum water bugs lay eggs on the hemelytra of their mates, where the eggs are brooded until hatching. Males use their hind legs to carry, aerate and protect the eggs. After controlling for covariance between variables, we fitted a series of structural equation models (SEMs) and evaluated the existence of sexual dimorphism in the size of the body and hind legs, in the shape and centroid size of the hemelytrum, and among the static allometry slopes of the size-related differences. Landmarks were used to capture phenotypic variation, by eliminating all non-shape variations with a Procrustes superimposition. Neither the shape of the hemelytrum nor its centroid size was related significantly to the aforementioned linear body measurements. Instead, the differences in the size of the hind legs were mediated by body dimensions only in males. We also found that males were wider and had longer heads than females, according to the SEM intercept values. Our findings suggest that sexual dimorphism in B. angustum may be related to a balance between sexual role reversal and viability costs.
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Affiliation(s)
- Cassiane Furlan Lopes
- Laboratório de Estudos da Biodiversidade do Pampa (LEBIP), Universidade Federal do Pampa, Campus São Gabriel, São Gabriel, Rio Grande do Sul State, Brazil
| | - Fabiano Stefanello
- Laboratório de Biologia Comparada e Abelhas, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, Ribeirão Preto, São Paulo, Brazil
| | - Christian Bugs
- Laboratório de Estudos da Biodiversidade do Pampa (LEBIP), Universidade Federal do Pampa, Campus São Gabriel, São Gabriel, Rio Grande do Sul State, Brazil
| | - Cristina Stenert
- Laboratório de Ecologia e Conservação de Ecossistemas Aquáticos, Universidade do Vale do Rio dos Sinos, Av. Unisinos, Cristo Rei, São Leopoldo, Rio Grande do Sul State, Brazil
| | - Leonardo Maltchik
- Laboratório de Ecologia e Conservação de Ecossistemas Aquáticos, Universidade do Vale do Rio dos Sinos, Av. Unisinos, Cristo Rei, São Leopoldo, Rio Grande do Sul State, Brazil
| | - José Ricardo Inacio Ribeiro
- Laboratório de Estudos da Biodiversidade do Pampa (LEBIP), Universidade Federal do Pampa, Campus São Gabriel, São Gabriel, Rio Grande do Sul State, Brazil
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García-Roger EM, Lubzens E, Fontaneto D, Serra M. Facing Adversity: Dormant Embryos in Rotifers. THE BIOLOGICAL BULLETIN 2019; 237:119-144. [PMID: 31714860 DOI: 10.1086/705701] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
An in-depth look at the basic aspects of dormancy in cyclic parthenogenetic organisms is now possible thanks to research efforts conducted over the past two decades with rotifer dormant embryos. In this review, we assemble and compose the current knowledge on four central themes: (1) distribution of dormancy in animals, with an overview on the phylogenetic distribution of embryo dormancy in metazoans, and (2) physiological and cellular processes involved in dormancy, with a strong emphasis on the dormant embryos of cyclically parthenogenetic monogonont rotifers; and discussions of (3) the selective pressures and (4) the evolutionary and population implications of dormancy in these animals. Dormancy in metazoans is a widespread phenomenon with taxon-specific features, and rotifers are among the animals in which dormancy is an intrinsic feature of their life cycle. Our review shows that embryo dormancy in rotifers shares common functional pathways with other taxa at the molecular and cellular level, despite the independent evolution of dormancy across phyla. These pathways include the arrest of similar metabolic routes and the usage of common metabolites for the stabilization of cellular structures and to confer stress resistance. We conclude that specific features of recurrent harsh environmental conditions are a powerful selective pressure for the fine-tuning of dormancy patterns in rotifers. We hypothesize that similar mechanisms at the organism level will lead to similar adaptive consequences at the population level across taxa, among which the formation of egg banks, the coexistence of species, and the possibility of differentiation among populations and local adaptation stand out. Our review shows how studies of rotifers have contributed to improved knowledge of all of these aspects.
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21
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Janzen FJ, Delaney DM, Mitchell TS, Warner DA. Do Covariances Between Maternal Behavior and Embryonic Physiology Drive Sex-Ratio Evolution Under Environmental Sex Determination? J Hered 2019; 110:411-421. [PMID: 30982894 DOI: 10.1093/jhered/esz021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 04/11/2019] [Indexed: 11/12/2022] Open
Abstract
Fisherian sex-ratio theory predicts sexual species should have a balanced primary sex ratio. However, organisms with environmental sex determination (ESD) are particularly vulnerable to experiencing skewed sex ratios when environmental conditions vary. Theoretical work has modeled sex-ratio dynamics for animals with ESD with regard to 2 traits predicted to be responsive to sex-ratio selection: 1) maternal oviposition behavior and 2) sensitivity of embryonic sex determination to environmental conditions, and much research has since focused on how these traits influence offspring sex ratios. However, relatively few studies have provided estimates of univariate quantitative genetic parameters for these 2 traits, and the existence of phenotypic or genetic covariances among these traits has not been assessed. Here, we leverage studies on 3 species of reptiles (2 turtle species and a lizard) with temperature-dependent sex determination (TSD) to assess phenotypic covariances between measures of maternal oviposition behavior and thermal sensitivity of the sex-determining pathway. These studies quantified maternal behaviors that relate to nest temperature and sex ratio of offspring incubated under controlled conditions. A positive covariance between these traits would enhance the efficiency of sex-ratio selection when primary sex ratio is unbalanced. However, we detected no such covariance between measures of these categories of traits in the 3 study species. These results suggest that maternal oviposition behavior and thermal sensitivity of sex determination in embryos might evolve independently. Such information is critical to understand how animals with TSD will respond to rapidly changing environments that induce sex-ratio selection.
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Affiliation(s)
- Fredric J Janzen
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA
| | - David M Delaney
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA
| | - Timothy S Mitchell
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN
| | - Daniel A Warner
- Department of Biological Sciences, Auburn University, Auburn, AL
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22
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Raffard A, Cucherousset J, Prunier JG, Loot G, Santoul F, Blanchet S. Variability of functional traits and their syndromes in a freshwater fish species ( Phoxinus phoxinus): The role of adaptive and nonadaptive processes. Ecol Evol 2019; 9:2833-2846. [PMID: 30891220 PMCID: PMC6405509 DOI: 10.1002/ece3.4961] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 12/14/2018] [Accepted: 12/20/2018] [Indexed: 12/25/2022] Open
Abstract
Functional traits can covary to form "functional syndromes." Describing and understanding functional syndromes is an important prerequisite for predicting the effects of organisms on ecosystem functioning. At the intraspecific level, functional syndromes have recently been described, but very little is known about their variability among populations and-if they vary-what the ecological and evolutionary drivers of this variation are. Here, we quantified and compared the variability in four functional traits (body mass, metabolic rate, excretion rate, and boldness), their covariations and the subsequent syndromes among thirteen populations of a common freshwater fish (the European minnow, Phoxinus phoxinus). We then tested whether functional traits and their covariations, as well as the subsequent syndromes, were underpinned by the phylogenetic relatedness among populations (historical effects) or the local environment (i.e., temperature and predation pressure), and whether adaptive (selection or plasticity) or nonadaptive (genetic drift) processes sustained among-population variability. We found substantial among-population variability in functional traits and trait covariations, and in the emerging syndromes. We further found that adaptive mechanisms (plasticity and/or selection) related to water temperature and predation pressure modulated the covariation between body mass and metabolic rate. Other trait covariations were more likely driven by genetic drift, suggesting that nonadaptive processes can also lead to substantial differences in trait covariations among populations. Overall, we concluded that functional syndromes are population-specific, and that both adaptive and nonadaptive processes are shaping functional traits. Given the pivotal role of functional traits, differences in functional syndromes within species provide interesting perspectives regarding the role of intraspecific diversity for ecosystem functioning.
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Affiliation(s)
- Allan Raffard
- CNRS, UMR‐5321, Station d’Écologie Théorique et Expérimentale du CNRS à MoulisUniversité Toulouse III Paul SabatierMoulisFrance
- EcoLab, Université de ToulouseCNRS, INPT, UPSToulouseFrance
| | - Julien Cucherousset
- CNRS, UMR‐5174 EDB (Laboratoire Evolution & Diversité Biologique)Université Toulouse III Paul SabatierToulouseFrance
| | - Jérôme G. Prunier
- CNRS, UMR‐5321, Station d’Écologie Théorique et Expérimentale du CNRS à MoulisUniversité Toulouse III Paul SabatierMoulisFrance
| | - Géraldine Loot
- CNRS, UMR‐5174 EDB (Laboratoire Evolution & Diversité Biologique)Université Toulouse III Paul SabatierToulouseFrance
| | | | - Simon Blanchet
- CNRS, UMR‐5321, Station d’Écologie Théorique et Expérimentale du CNRS à MoulisUniversité Toulouse III Paul SabatierMoulisFrance
- CNRS, UMR‐5174 EDB (Laboratoire Evolution & Diversité Biologique)Université Toulouse III Paul SabatierToulouseFrance
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23
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Yang Y, Wang H, Harrison SP, Prentice IC, Wright IJ, Peng C, Lin G. Quantifying leaf-trait covariation and its controls across climates and biomes. THE NEW PHYTOLOGIST 2019; 221:155-168. [PMID: 30272817 DOI: 10.1111/nph.15422] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 07/10/2018] [Indexed: 05/18/2023]
Abstract
Plant functional ecology requires the quantification of trait variation and its controls. Field measurements on 483 species at 48 sites across China were used to analyse variation in leaf traits, and assess their predictability. Principal components analysis (PCA) was used to characterize trait variation, redundancy analysis (RDA) to reveal climate effects, and RDA with variance partitioning to estimate separate and overlapping effects of site, climate, life-form and family membership. Four orthogonal dimensions of total trait variation were identified: leaf area (LA), internal-to-ambient CO2 ratio (χ), leaf economics spectrum traits (specific leaf area (SLA) versus leaf dry matter content (LDMC) and nitrogen per area (Narea )), and photosynthetic capacities (Vcmax , Jmax at 25°C). LA and χ covaried with moisture index. Site, climate, life form and family together explained 70% of trait variance. Families accounted for 17%, and climate and families together 29%. LDMC and SLA showed the largest family effects. Independent life-form effects were small. Climate influences trait variation in part by selection for different life forms and families. Trait values derived from climate data via RDA showed substantial predictive power for trait values in the available global data sets. Systematic trait data collection across all climates and biomes is still necessary.
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Affiliation(s)
- Yanzheng Yang
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
- Joint Center for Global Change Studies (JCGCS), Beijing, 100875, China
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Han Wang
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Sandy P Harrison
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, China
- School of Archaeology, Geography and Environmental Sciences (SAGES), University of Reading, Reading, RG6 6AH, UK
| | - I Colin Prentice
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, China
- AXA Chair of Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Ian J Wright
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Changhui Peng
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Department of Biological Sciences, Institute of Environmental Sciences, University of Quebec at Montreal, C.P. 8888, Succ. Centre-Ville, Montréal, H3C 3P8, QC, Canada
| | - Guanghui Lin
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
- Key Laboratory of Stable Isotope and Gulf Ecology, Graduate School at Shenzhen, Tsinghua University, Shenzhen, Guangdong, 518055, China
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Hahn PG, Agrawal AA, Sussman KI, Maron JL. Population Variation, Environmental Gradients, and the Evolutionary Ecology of Plant Defense against Herbivory. Am Nat 2018; 193:20-34. [PMID: 30624107 DOI: 10.1086/700838] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A central tenet of plant defense theory is that adaptation to the abiotic environment sets the template for defense strategies, imposing a trade-off between plant growth and defense. Yet this trade-off, commonly found among species occupying divergent resource environments, may not occur across populations of single species. We hypothesized that more favorable climates and higher levels of herbivory would lead to increases in growth and defense across plant populations. We evaluated whether plant growth and defense traits covaried across 18 populations of showy milkweed (Asclepias speciosa) inhabiting an east-west climate gradient spanning 25° of longitude. A suite of traits impacting defense (e.g., latex, cardenolides), growth (e.g., size), or both (e.g., specific leaf area [SLA], trichomes) were measured in natural populations and in a common garden, allowing us to evaluate plastic and genetically based variation in these traits. In natural populations, herbivore pressure increased toward warmer sites with longer growing seasons. Growth and defense traits showed strong clinal patterns and were positively correlated. In a common garden, clines with climatic origin were recapitulated only for defense traits. Correlations between growth and defense traits were also weaker and more negative in the common garden than in the natural populations. Thus, our data suggest that climatically favorable sites likely facilitate the evolution of greater defense at minimal costs to growth, likely because of increased resource acquisition.
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25
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Ligon RA, Diaz CD, Morano JL, Troscianko J, Stevens M, Moskeland A, Laman TG, Scholes E. Evolution of correlated complexity in the radically different courtship signals of birds-of-paradise. PLoS Biol 2018; 16:e2006962. [PMID: 30457985 PMCID: PMC6245505 DOI: 10.1371/journal.pbio.2006962] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/17/2018] [Indexed: 12/25/2022] Open
Abstract
Ornaments used in courtship often vary wildly among species, reflecting the evolutionary interplay between mate preference functions and the constraints imposed by natural selection. Consequently, understanding the evolutionary dynamics responsible for ornament diversification has been a longstanding challenge in evolutionary biology. However, comparing radically different ornaments across species, as well as different classes of ornaments within species, is a profound challenge to understanding diversification of sexual signals. Using novel methods and a unique natural history dataset, we explore evolutionary patterns of ornament evolution in a group—the birds-of-paradise—exhibiting dramatic phenotypic diversification widely assumed to be driven by sexual selection. Rather than the tradeoff between ornament types originally envisioned by Darwin and Wallace, we found positive correlations among cross-modal (visual/acoustic) signals indicating functional integration of ornamental traits into a composite unit—the “courtship phenotype.” Furthermore, given the broad theoretical and empirical support for the idea that systemic robustness—functional overlap and interdependency—promotes evolutionary innovation, we posit that birds-of-paradise have radiated extensively through ornamental phenotype space as a consequence of the robustness in the courtship phenotype that we document at a phylogenetic scale. We suggest that the degree of robustness in courtship phenotypes among taxa can provide new insights into the relative influence of sexual and natural selection on phenotypic radiations. Animals frequently vary widely in ornamentation, even among closely related species. Understanding the patterns that underlie this variation is a significant challenge, requiring comparisons among drastically different traits—like comparing apples to oranges. Here, we use novel analytical approaches to quantify variation in ornamental diversity and richness across the wildly divergent birds-of-paradise, a textbook example of how sexual selection can profoundly shape organismal phenotypes. We find that color and acoustic complexity, along with behavior and acoustic complexity, are positively correlated across evolutionary timescales. Positive links among ornament classes suggests that selection is acting on correlated suites of traits—a composite courtship phenotype—and this integration may be partially responsible for the extreme variation in signal form that we see in birds-of-paradise.
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Affiliation(s)
- Russell A. Ligon
- Cornell Lab of Ornithology, Cornell University, Ithaca, New York, United States of America
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York, United States of America
- * E-mail:
| | - Christopher D. Diaz
- Cornell Lab of Ornithology, Cornell University, Ithaca, New York, United States of America
| | - Janelle L. Morano
- Cornell Lab of Ornithology, Cornell University, Ithaca, New York, United States of America
| | - Jolyon Troscianko
- Centre for Ecology and Conservation, College of Life and Environmental Science, University of Exeter, Penryn, United Kingdom
| | - Martin Stevens
- Centre for Ecology and Conservation, College of Life and Environmental Science, University of Exeter, Penryn, United Kingdom
| | - Annalyse Moskeland
- Cornell Lab of Ornithology, Cornell University, Ithaca, New York, United States of America
| | - Timothy G. Laman
- Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Edwin Scholes
- Cornell Lab of Ornithology, Cornell University, Ithaca, New York, United States of America
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Dahirel M, De Cock M, Vantieghem P, Bonte D. Urbanization-driven changes in web building and body size in an orb web spider. J Anim Ecol 2018; 88:79-91. [PMID: 30280386 DOI: 10.1111/1365-2656.12909] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 09/07/2018] [Indexed: 12/23/2022]
Abstract
In animals, behavioural responses may play an important role in determining population persistence in the face of environmental changes. Body size is a key trait central to many life-history traits and behaviours. Correlations with body size may constrain behavioural variation in response to environmental changes, especially when size itself is influenced by environmental conditions. Urbanization is an important human-induced rapid environmental change that imposes multiple selection pressures on both body size and (size-constrained) behaviour. How these combine to shape behavioural responses of urban-dwelling species is unclear. Using web building, an easily quantifiable behaviour linked to body size and the garden spider Araneus diadematus as a model, we evaluated direct behavioural responses to urbanization and body size constraints across a network of 63 selected populations differing in urbanization intensity. We additionally studied urbanization at two spatial scales to account for some environmental pressures varying across scales and to obtain first qualitative insights about the role of plasticity and genetic selection. Spiders were smaller in highly urbanized sites (local scale only), in line with expectations based on reduced prey biomass availability and the Urban Heat Island effect. Web surface and mesh width decreased with urbanization at the local scale, while web surface also increased with urbanization at the landscape scale. The latter two responses are expected to compensate, at least in part, for reduced prey biomass availability in cities. The use of multivariate mixed modelling reveals that although web traits and body size are correlated within populations, behavioural responses to urbanization do not appear to be constrained by size: there is no evidence of size-web correlations among populations or among landscapes, and web traits appear independent from each other. Our results demonstrate that responses in size-dependent behaviours may be decoupled from size changes, thereby allowing fitness maximization in novel environments. The spatial scale at which traits respond suggests contributions of both genetic adaptation (for web investment) and plasticity (for mesh width). Although fecundity decreased with local-scale urbanization, A. diadematus abundances were similar across urbanization gradients; behavioural responses thus appear overall successful at the population level.
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Affiliation(s)
- Maxime Dahirel
- Terrestrial Ecology Unit, Department of Biology, Ghent University, Gent, Belgium.,Univ Rennes, CNRS, ECOBIO (Ecosystèmes, biodiversité, évolution) - UMR 6553, Rennes, France
| | - Maarten De Cock
- Terrestrial Ecology Unit, Department of Biology, Ghent University, Gent, Belgium
| | - Pieter Vantieghem
- Terrestrial Ecology Unit, Department of Biology, Ghent University, Gent, Belgium
| | - Dries Bonte
- Terrestrial Ecology Unit, Department of Biology, Ghent University, Gent, Belgium
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Debecker S, Stoks R. Pace of life syndrome under warming and pollution: integrating life history, behavior, and physiology across latitudes. ECOL MONOGR 2018. [DOI: 10.1002/ecm.1332] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Sara Debecker
- Evolutionary Stress Ecology and Ecotoxicology; KU Leuven (University of Leuven); Charles Deberiotstraat 32 3000 Leuven Belgium
| | - Robby Stoks
- Evolutionary Stress Ecology and Ecotoxicology; KU Leuven (University of Leuven); Charles Deberiotstraat 32 3000 Leuven Belgium
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Messier J, Violle C, Enquist BJ, Lechowicz MJ, McGill BJ. Similarities and differences in intrapopulation trait correlations of co-occurring tree species: consistent water-use relationships amid widely different correlation patterns. AMERICAN JOURNAL OF BOTANY 2018; 105:1477-1490. [PMID: 30216410 DOI: 10.1002/ajb2.1146] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 05/16/2018] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY General relationships among functional traits have been identified across species, but the forces shaping these relationships remain largely unknown. Adopting an approach from evolutionary biology, we studied similarities and differences in intrapopulation trait correlations among locally co-occurring tree species to assess the roles of constraints, phylogeny, and the environmental niche in shaping multivariate phenotypes. We tested the hypotheses (1) that intrapopulation correlations among functional traits are largely shaped by fundamental trade-offs or constraints and (2) that differences among species reflect adaptation to their environmental niches. METHODS We compared pairwise correlations and correlation matrices of 17 key functional traits within and among temperate tree species. These traits describe three well-established trade-off dimensions characterizing interspecific relationships among physiological functions: resource acquisition and conservation; sap transport and mechanical support; and branch architecture. KEY RESULTS Six trait pairs are consistently correlated within populations. Of these, only one involves dimensionally independent traits: LMA-δ13 C. For all other traits, intrapopulation functional trait correlations are weak, are species-specific, and differ from interspecific correlations. Species intrapopulation correlation matrices are related to neither phylogeny nor environmental niche. CONCLUSIONS The results (1) suggest that the functional design of these species is centered on efficient water use, (2) highlight flexibility in plant functional design across species, and (3) suggest that intrapopulation, local interspecific, and global interspecific correlations are shaped by processes acting at each of these scales.
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Affiliation(s)
- Julie Messier
- Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721, USA
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec, J1K 2R1, Canada
| | - Cyrille Violle
- CNRS, CEFE UMR 5175, Université de Montpellier-Université Paul Valéry-EPHE, Montpellier, 34293, France
| | - Brian J Enquist
- Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721, USA
- Santa Fe Institute, Santa Fe, New Mexico, 87501, USA
| | | | - Brian J McGill
- School of Biology and Ecology, University of Maine, Orono, Maine, 04469, USA
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Abbott JM, DuBois K, Grosberg RK, Williams SL, Stachowicz JJ. Genetic distance predicts trait differentiation at the subpopulation but not the individual level in eelgrass, Zostera marina. Ecol Evol 2018; 8:7476-7489. [PMID: 30151164 PMCID: PMC6106171 DOI: 10.1002/ece3.4260] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 03/29/2018] [Accepted: 05/15/2018] [Indexed: 11/08/2022] Open
Abstract
Ecological studies often assume that genetically similar individuals will be more similar in phenotypic traits, such that genetic diversity can serve as a proxy for trait diversity. Here, we explicitly test the relationship between genetic relatedness and trait distance using 40 eelgrass (Zostera marina) genotypes from five sites within Bodega Harbor, CA. We measured traits related to nutrient uptake, morphology, biomass and growth, photosynthesis, and chemical deterrents for all genotypes. We used these trait measurements to calculate a multivariate pairwise trait distance for all possible genotype combinations. We then estimated pairwise relatedness from 11 microsatellite markers. We found significant trait variation among genotypes for nearly every measured trait; however, there was no evidence of a significant correlation between pairwise genetic relatedness and multivariate trait distance among individuals. However, at the subpopulation level (sites within a harbor), genetic (FST) and trait differentiation were positively correlated. Our work suggests that pairwise relatedness estimated from neutral marker loci is a poor proxy for trait differentiation between individual genotypes. It remains to be seen whether genomewide measures of genetic differentiation or easily measured "master" traits (like body size) might provide good predictions of overall trait differentiation.
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Affiliation(s)
- Jessica M. Abbott
- Center for Population BiologyUniversity of CaliforniaDavisCalifornia
- Department of Evolution and EcologyUniversity of CaliforniaDavisCalifornia
- Institute for Wildlife StudiesArcataCalifornia
| | - Katherine DuBois
- Department of Evolution and EcologyUniversity of CaliforniaDavisCalifornia
- Bodega Marine LaboratoryBodega BayCalifornia
| | - Richard K. Grosberg
- Center for Population BiologyUniversity of CaliforniaDavisCalifornia
- Department of Evolution and EcologyUniversity of CaliforniaDavisCalifornia
| | - Susan L. Williams
- Department of Evolution and EcologyUniversity of CaliforniaDavisCalifornia
- Bodega Marine LaboratoryBodega BayCalifornia
| | - John J. Stachowicz
- Center for Population BiologyUniversity of CaliforniaDavisCalifornia
- Department of Evolution and EcologyUniversity of CaliforniaDavisCalifornia
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30
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Galloway LF, Watson RHB, Prendeville HR. Response to joint selection on germination and flowering phenology depends on the direction of selection. Ecol Evol 2018; 8:7688-7696. [PMID: 30151182 PMCID: PMC6106181 DOI: 10.1002/ece3.4334] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/11/2018] [Accepted: 06/15/2018] [Indexed: 01/03/2023] Open
Abstract
Flowering and germination time are components of phenology, a complex phenotype that incorporates a number of traits. In natural populations, selection is likely to occur on multiple components of phenology at once. However, we have little knowledge of how joint selection on several phenological traits influences evolutionary response. We conducted one generation of artificial selection for all combinations of early and late germination and flowering on replicated lines within two independent base populations in the herb Campanula americana. We then measured response to selection and realized heritability for each trait. Response to selection and heritability were greater for flowering time than germination time, indicating greater evolutionary potential of this trait. Selection for earlier phenology, both flowering and germination, did not depend on the direction of selection on the other trait, whereas response to selection to delay germination and flowering was greater when selection on the other trait was in the opposite direction (e.g., early germination and late flowering), indicating a negative genetic correlation between the traits. Therefore, the extent to which correlations shaped response to selection depended on the direction of selection. Furthermore, the genetic correlation between timing of germination and flowering varies across the trait distributions. The negative correlation between germination and flowering time found when selecting for delayed phenology follows theoretical predictions of constraint for traits that jointly determine life history schedule. In contrast, the lack of constraint found when selecting for an accelerated phenology suggests a reduction of the covariance due to strong selection favoring earlier flowering and a shorter life cycle. This genetic architecture, in turn, will facilitate further evolution of the early phenology often favored in warm climates.
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Affiliation(s)
| | - Ray H. B. Watson
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginia
| | - Holly R. Prendeville
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginia
- Present address:
USDA FS Pacific Northwest Research StationCorvallisOregon
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Brans KI, Stoks R, De Meester L. Urbanization drives genetic differentiation in physiology and structures the evolution of pace-of-life syndromes in the water flea Daphnia magna. Proc Biol Sci 2018; 285:rspb.2018.0169. [PMID: 30051844 DOI: 10.1098/rspb.2018.0169] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 06/22/2018] [Indexed: 11/12/2022] Open
Abstract
Natural and human-induced stressors elicit changes in energy metabolism and stress physiology in populations of a wide array of species. Cities are stressful environments that may lead to differential selection on stress-coping mechanisms. Given that city ponds are exposed to the urban heat island effect and receive polluted run-off, organisms inhabiting these ecosystems might show genetic differentiation for physiological traits enabling them to better cope with higher overall stress levels. A common garden study with 62 Daphnia magna genotypes from replicated urban and rural populations revealed that urban Daphnia have significantly higher concentrations of total body fat, proteins and sugars. Baseline activity levels of the antioxidant defence enzymes superoxide dismutase (SOD) and glutathione-S-transferase (GST) were higher in rural compared with city populations, yet urban animals were equally well protected against lipid peroxidation. Our results add to the recent evidence of urbanization-driven changes in stress physiology and energy metabolism in terrestrial organisms. Combining our results with data on urban life history evolution in Daphnia revealed that urban genotypes show a structured pace-of-life syndrome involving both life-history and physiological traits, whereas this is absent in rural populations.
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Affiliation(s)
- Kristien I Brans
- Laboratory of Aquatic Ecology, Evolution and Conservation, KU Leuven, Ch. Deberiotstraat 32, 3000, Leuven, Belgium
| | - Robby Stoks
- Laboratory of Evolutionary Stress Ecology and Ecotoxicology, KU Leuven, Ch. Deberiotstraat 32, 3000, Leuven, Belgium
| | - Luc De Meester
- Laboratory of Aquatic Ecology, Evolution and Conservation, KU Leuven, Ch. Deberiotstraat 32, 3000, Leuven, Belgium
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