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Haines GE, Moisan L, Derry AM, Hendry AP. Corrigendum. Am Nat 2024; 203:147-159. [PMID: 38207146 DOI: 10.1086/728406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
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Haines GE, Moisan L, Derry AM, Hendry AP. Dimensionality and Modularity of Adaptive Variation: Divergence in Threespine Stickleback from Diverse Environments. Am Nat 2023; 201:175-199. [PMID: 36724467 DOI: 10.1086/722483] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
AbstractPopulations are subjected to diverse environmental conditions that affect fitness and induce evolutionary or plastic responses, resulting in phenotypic divergence. Some authors contend that such divergence is concentrated along a single major axis of trait covariance even if that axis does not lead populations directly toward a fitness optimum. Other authors argue that divergence can occur readily along many phenotype axes at the same time. We use populations of threespine stickleback (Gasterosteus aculeatus) from 14 lakes with contrasting ecological conditions to find some resolution along the continuum between these two extremes. Unlike many previous studies, we included several functional suites of traits (defensive, swimming, trophic) potentially subject to different sources of selection. We find that populations exhibit dimensionality of divergence that is high enough to preclude a history of constraint along a single axis-both for divergence in multivariate mean trait values and for the structure of trait covariances. Dimensionality varied among trait suites and were strongly influenced by the inclusion of specific traits, and integration of trait suites varied between populations. We leverage this variation into new insights about the process of divergence and suggest that similar analyses could increase understanding of other adaptive radiations.
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Schwarz R, Stark G, Antonopolous A, Itescu Y, Pafilis P, Chapple DG, Meiri S. Specialist versus Generalist at the Intraspecific Level: Functional Morphology and Substrate Preference of Mediodactylus kotschyi Geckos. Integr Comp Biol 2021; 61:62-75. [PMID: 34010416 DOI: 10.1093/icb/icab066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Populations of the same species occupying different microhabitats can either exhibit generalized traits across them or display intraspecific variability, adapting to each microhabitat in order to maximize performance. Intraspecific variability contributes to the generation of diversity, following selection and adaptation, and understanding such variability is important for comprehending how individuals choose their microhabitats. Compared with interspecific variability, however, intraspecific variability in functional morphology and its relationship with microhabitat preference and use have been relatively little studied. Here we examined whether populations of the gecko Mediodactylus kotschyi that differ in the substrates they occupy display habitat-specific behaviors and differing morphologies associated with functional adaptation to their microhabitats. We collected 207 geckos from under or on rocks or on trees from seven populations in Greece. On large islands individuals occupy both substrates; whereas small islets are devoid of trees and the geckos are restricted to rocks, while on the mainland they are only found on trees. We determined gecko substrate preferences in the laboratory, together with their clinging abilities to the different substrates. We measured their limbs, digits, and claws and assessed how these measurements relate to clinging ability. Geckos from all populations preferred the tree made available to them, but this preference was not statistically significant. Geckos from both large and small islands clung better to the tree than to the rock in the laboratory, while those from the mainland clung similarly to both substrates. Geckos collected from trees had longer manual digits and hind limbs. Geckos collected from large and small islands had taller (longer on the dorso-ventral axis; henceforth "deeper") claws. Longer digits and deeper but shorter claws were associated with a better ability to cling to rocks. Our findings suggest that while M. kotschyi is potentially preferentially arboreal, due to the great variation and plasticity it possesses, it can successfully also exploit the habitats available on the smallest, treeless islets in the Aegean Sea. Our study suggests that the dichotomous use of generalist versus specialist in describing species' habitat use is oversimplified, and we suggest the use of a generalist-specialist gradient instead.
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Affiliation(s)
- Rachel Schwarz
- School of Zoology, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Gavin Stark
- School of Zoology, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Antonis Antonopolous
- Department of Biology, National and Kapodistrian University of Athens, Athens 157 72, Greece
| | - Yuval Itescu
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin 12587, Germany.,Institute of Biology, Freie Universität Berlin, Berlin 14195, Germany
| | - Panayiotis Pafilis
- Department of Biology, National and Kapodistrian University of Athens, Athens 157 72, Greece
| | - David G Chapple
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Shai Meiri
- School of Zoology, Tel Aviv University, Tel Aviv 6997801, Israel.,The Steinhardt Museum of Natural History, Tel Aviv University, Tel Aviv 6997801, Israel
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Chavarie L, Howland KL, Harris LN, Gallagher CP, Hansen MJ, Tonn WM, Muir AM, Krueger CC. Among-individual diet variation within a lake trout ecotype: Lack of stability of niche use. Ecol Evol 2021; 11:1457-1475. [PMID: 33598144 PMCID: PMC7863394 DOI: 10.1002/ece3.7158] [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: 07/30/2020] [Revised: 11/17/2020] [Accepted: 12/02/2020] [Indexed: 11/22/2022] Open
Abstract
In a polyphenic species, differences in resource use are expected among ecotypes, and homogeneity in resource use is expected within an ecotype. Yet, using a broad resource spectrum has been identified as a strategy for fishes living in unproductive northern environments, where food is patchily distributed and ephemeral. We investigated whether specialization of trophic resources by individuals occurred within the generalist piscivore ecotype of lake trout from Great Bear Lake, Canada, reflective of a form of diversity. Four distinct dietary patterns of resource use within this lake trout ecotype were detected from fatty acid composition, with some variation linked to spatial patterns within Great Bear Lake. Feeding habits of different groups within the ecotype were not associated with detectable morphological or genetic differentiation, suggesting that behavioral plasticity caused the trophic differences. A low level of genetic differentiation was detected between exceptionally large-sized individuals and other piscivore individuals. We demonstrated that individual trophic specialization can occur within an ecotype inhabiting a geologically young system (8,000-10,000 yr BP), a lake that sustains high levels of phenotypic diversity of lake trout overall. The characterization of niche use among individuals, as done in this study, is necessary to understand the role that individual variation can play at the beginning of differentiation processes.
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Affiliation(s)
- Louise Chavarie
- Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life SciencesÅsNorway
- Scottish Centre for Ecology and the Natural EnvironmentIBAHCMGlasgowUK
- Department of Fisheries and WildlifeCenter for Systems Integration and SustainabilityMichigan State UniversityEast LansingMIUSA
| | - Kimberly L. Howland
- Fisheries and Oceans CanadaWinnipegMBCanada
- Department of Biological SciencesUniversity of AlbertaEdmontonABCanada
| | | | | | - Michael J. Hansen
- U.S. Geological Survey (retired)Hammond Bay Biological StationMillersburgMIUSA
| | - William M. Tonn
- Department of Biological SciencesUniversity of AlbertaEdmontonABCanada
| | | | - Charles C. Krueger
- Department of Fisheries and WildlifeCenter for Systems Integration and SustainabilityMichigan State UniversityEast LansingMIUSA
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Chavarie L, Howland KL, Harris LN, Hansen MJ, Harford WJ, Gallagher CP, Baillie SM, Malley B, Tonn WM, Muir AM, Krueger CC. From top to bottom: Do Lake Trout diversify along a depth gradient in Great Bear Lake, NT, Canada? PLoS One 2018; 13:e0193925. [PMID: 29566015 PMCID: PMC5863968 DOI: 10.1371/journal.pone.0193925] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 02/21/2018] [Indexed: 11/19/2022] Open
Abstract
Depth is usually considered the main driver of Lake Trout intraspecific diversity across lakes in North America. Given that Great Bear Lake is one of the largest and deepest freshwater systems in North America, we predicted that Lake Trout intraspecific diversity to be organized along a depth axis within this system. Thus, we investigated whether a deep-water morph of Lake Trout co-existed with four shallow-water morphs previously described in Great Bear Lake. Morphology, neutral genetic variation, isotopic niches, and life-history traits of Lake Trout across depths (0-150 m) were compared among morphs. Due to the propensity of Lake Trout with high levels of morphological diversity to occupy multiple habitat niches, a novel multivariate grouping method using a suite of composite variables was applied in addition to two other commonly used grouping methods to classify individuals. Depth alone did not explain Lake Trout diversity in Great Bear Lake; a distinct fifth deep-water morph was not found. Rather, Lake Trout diversity followed an ecological continuum, with some evidence for adaptation to local conditions in deep-water habitat. Overall, trout caught from deep-water showed low levels of genetic and phenotypic differentiation from shallow-water trout, and displayed higher lipid content (C:N ratio) and occupied a higher trophic level that suggested an potential increase of piscivory (including cannibalism) than the previously described four morphs. Why phenotypic divergence between shallow- and deep-water Lake Trout was low is unknown, especially when the potential for phenotypic variation should be high in deep and large Great Bear Lake. Given that variation in complexity of freshwater environments has dramatic consequences for divergence, variation in the complexity in Great Bear Lake (i.e., shallow being more complex than deep), may explain the observed dichotomy in the expression of intraspecific phenotypic diversity between shallow- vs. deep-water habitats. The ambiguity surrounding mechanisms driving divergence of Lake Trout in Great Bear Lake should be seen as reflective of the highly variable nature of ecological opportunity and divergent natural selection itself.
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Affiliation(s)
- Louise Chavarie
- Department of Fisheries and Wildlife, Center for Systems Integration and Sustainability, Michigan State University, East Lansing, MI, United States of America
- * E-mail:
| | - Kimberly L. Howland
- Fisheries and Oceans Canada, Winnipeg, Canada
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | | | - Michael J. Hansen
- U.S. Geological Survey, Hammond Bay Biological Station, Millersburg, MI, United States of America
| | - William J. Harford
- Cooperative Institute of Marine & Atmospheric Studies, University of Miami, Miami, FL, United States of America
| | | | | | | | - William M. Tonn
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | - Andrew M. Muir
- Great Lakes Fishery Commission, Ann Arbor, MI, United States of America
| | - Charles C. Krueger
- Department of Fisheries and Wildlife, Center for Systems Integration and Sustainability, Michigan State University, East Lansing, MI, United States of America
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Kahilainen KK, Thomas SM, Nystedt EKM, Keva O, Malinen T, Hayden B. Ecomorphological divergence drives differential mercury bioaccumulation in polymorphic European whitefish (Coregonus lavaretus) populations of subarctic lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:1768-1778. [PMID: 28545204 DOI: 10.1016/j.scitotenv.2017.05.099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 06/07/2023]
Abstract
Resource polymorphism, whereby ancestral trophic generalists undergo divergence into multiple specialist morphs, is common in salmonid fish populations inhabiting subarctic lakes. However, the extent to which such resource specialization into the three principal lake habitats (littoral, profundal, and pelagic) affects patterns of contaminant bioaccumulation remains largely unexplored. We assessed total mercury concentrations (THg) of European whitefish (Coregonus lavaretus (L.)) and their invertebrate prey in relation to potential explanatory variables across 6 subarctic lakes, of which three are inhabited by polymorphic (comprised of four morphs) and three by monomorphic populations. Among invertebrate prey, the highest THg concentrations were observed in profundal benthic macroinvertebrates, followed by pelagic zooplankton, with concentrations lowest in littoral benthic macroinvertebrates in both lake types. Broadly similar patterns were apparent in whitefish in polymorphic systems, where average age-corrected THg concentrations and bioaccumulation rates were the highest in pelagic morphs, intermediate in the profundal morph, and the lowest in the littoral morph. In monomorphic systems, age-corrected THg concentrations were generally lower, and showed pronounced lake-specific variation. In the polymorphic systems, we found significant relationships between whitefish muscle tissue THg concentration and gill raker count, resource use, lipid content and maximum length, whilst no such relationships were apparent in the monomorphic systems. Across all polymorphic lakes, the major variables explaining THg in whitefish were gill raker count and age, whereas in monomorphic systems, the factors were lake-specific. Whitefish resource polymorphism across the three main lake habitats therefore appears to have profound impacts on THg concentration and bioaccumulation rate. This highlights the importance of recognizing such intraspecific diversity in both future scientific studies and mercury monitoring programs.
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Affiliation(s)
- Kimmo K Kahilainen
- Department of Environmental Sciences, University of Helsinki, P.O. Box 65, FIN-00014, Finland; Kilpisjärvi Biological Station, Käsivarrentie 14622, FIN-99490 Kilpisjärvi, Finland.
| | - Stephen M Thomas
- Department of Environmental Sciences, University of Helsinki, P.O. Box 65, FIN-00014, Finland
| | - Elina K M Nystedt
- Department of Environmental Sciences, University of Helsinki, P.O. Box 65, FIN-00014, Finland
| | - Ossi Keva
- Department of Environmental Sciences, University of Helsinki, P.O. Box 65, FIN-00014, Finland
| | - Tommi Malinen
- Department of Environmental Sciences, University of Helsinki, P.O. Box 65, FIN-00014, Finland
| | - Brian Hayden
- Canadian Rivers Institute, Biology Department, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
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Chavarie L, Muir AM, Zimmerman MS, Baillie SM, Hansen MJ, Nate NA, Yule DL, Middel T, Bentzen P, Krueger CC. Challenge to the model of lake charr evolution: shallow- and deep-water morphs exist within a small postglacial lake. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12913] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Louise Chavarie
- Center for Systems Integration and Sustainability; Michigan State University; 115 Manly Miles Building, 1405 South Harrison Road East Lansing Michigan USA
| | - Andrew M. Muir
- Great Lakes Fishery Commission; 2100 Commonwealth Blvd. Suite 100 Ann Arbor Michigan USA
| | - Mara S. Zimmerman
- Washington Department of Fish and Wildlife; 600 Capitol Way N. Olympia Washington USA
| | - Shauna M. Baillie
- Department of Biology; Dalhousie University; 1355 Oxford St. Halifax Nova Scotia Canada
| | - Michael J. Hansen
- United States Geological Survey; Hammond Bay Biological Station; 11188 Ray Road Millersburg Michigan USA
| | - Nancy A. Nate
- Center for Systems Integration and Sustainability; Michigan State University; 115 Manly Miles Building, 1405 South Harrison Road East Lansing Michigan USA
| | - Daniel L. Yule
- United States Geological Survey; Lake Superior Biological Station; 2800 Lakeshore Drive Ashland Wisconsin USA
| | - Trevor Middel
- Harkness Laboratory of Fisheries Research; Ontario Ministry of Natural Resources and Forestry; Trent University; 2140 East Bank Drive Peterborough Ontario Canada
| | - Paul Bentzen
- Department of Biology; Dalhousie University; 1355 Oxford St. Halifax Nova Scotia Canada
| | - Charles C. Krueger
- Center for Systems Integration and Sustainability; Michigan State University; 115 Manly Miles Building, 1405 South Harrison Road East Lansing Michigan USA
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Chavarie L, Harford WJ, Howland KL, Fitzsimons J, Muir AM, Krueger CC, Tonn WM. Multiple generalist morphs of Lake Trout: Avoiding constraints on the evolution of intraspecific divergence? Ecol Evol 2016; 6:7727-7741. [PMID: 30128124 PMCID: PMC6093156 DOI: 10.1002/ece3.2506] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 08/26/2016] [Accepted: 08/30/2016] [Indexed: 12/29/2022] Open
Abstract
A generalist strategy, as an adaptation to environmental heterogeneity, is common in Arctic freshwater systems, often accompanied, however, by intraspecific divergence that promotes specialization in niche use. To better understand how resources may be partitioned in a northern system that supports intraspecific diversity of Lake Trout, trophic niches were compared among four shallow‐water morphotypes in Great Bear Lake (N65° 56′ 39″, W120° 50′ 59″). Bayesian mixing model analyses of stable isotopes of carbon and nitrogen were conducted on adult Lake Trout. Major niche overlap in resource use among four Lake Trout morphotypes was found within littoral and pelagic zones, which raises the question of how such polymorphism can be sustained among opportunistic generalist morphotypes. Covariances of our morphological datasets were tested against δ13C and δ15N values. Patterns among morphotypes were mainly observed for δ15N. This link between ecological and morphological differentiation suggested that selection pressure(s) operate at the trophic level (δ15N), independent of habitat, rather than along the habitat‐foraging opportunity axis (δ13C). The spatial and temporal variability of resources in Arctic lakes, such as Great Bear Lake, may have favored the presence of multiple generalists showing different degrees of omnivory along a weak benthic–pelagic gradient. Morphs 1–3 had more generalist feeding habits using both benthic and pelagic habitats than Morph 4, which was a top‐predator specialist in the pelagic habitat. Evidence for frequent cannibalism in Great Bear Lake was found across all four morphotypes and may also contribute to polymorphism. We suggest that the multiple generalist morphs described here from Great Bear Lake are a unique expression of diversity due to the presumed constraints on the evolution of generalists and contrast with the development of multiple specialists, the standard response to intraspecific divergence.
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Affiliation(s)
- Louise Chavarie
- Center for Systems Integration and Sustainability Michigan State University East Lansing MI USA.,Department of Biological Sciences University of Alberta Edmonton AB Canada
| | - William J Harford
- Cooperative Institute of Marine & Atmospheric Studies University of Miami Miami FL USA
| | - Kimberly L Howland
- Department of Biological Sciences University of Alberta Edmonton AB Canada.,Fisheries and Oceans Canada Winnipeg MB Canada
| | | | | | - Charles C Krueger
- Center for Systems Integration and Sustainability Michigan State University East Lansing MI USA
| | - William M Tonn
- Department of Biological Sciences University of Alberta Edmonton AB Canada
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