TY - JOUR T1 - Genotypic variation in foundation species generates network structure that may drive community dynamics and evolution. JF - Ecology Y1 - 2016 A1 - Lau,Matthew K A1 - Keith,Arthur R A1 - Borrett,Stuart R A1 - Shuster,Stephen M A1 - Whitham,Thomas G KW - Animals KW - Biological Evolution KW - Computer Simulation KW - Food Chain KW - Genetic Variation KW - Genotype KW - Insecta KW - Models, Biological KW - Populus AB -

Although genetics in a single species is known to impact whole communities, little is known about how genetic variation influences species interaction networks in complex ecosystems. Here, we examine the interactions in a community of arthropod species on replicated genotypes (clones) of a foundation tree species, Populus angustifolia James (narrowleaf cottonwood), in a long-term, common garden experiment using a bipartite "genotype-species" network perspective. We combine this empirical work with a simulation experiment designed to further investigate how variation among individual tree genotypes can impact network structure. Three findings emerged: (1) the empirical "genotype-species network" exhibited significant network structure with modularity being greater than the highly conservative null model; (2) as would be expected given a modular network structure, the empirical network displayed significant positive arthropod co-occurrence patterns; and (3) furthermore, the simulations of "genotype-species" networks displayed variation in network structure, with modularity in particular clearly increasing, as genotypic variation increased. These results support the conclusion that genetic variation in a single species contributes to the structure of ecological interaction networks, which could influence eco-ogical dynamics (e.g., assembly and stability) and evolution in a community context.

VL - 97 SN - 0012-9658 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=27197399&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 3 ER - TY - JOUR T1 - Phylogenetic organization of bacterial activity. JF - The ISME journal Y1 - 2016 A1 - Ember M Morrissey A1 - Mau,Rebecca L A1 - Egbert Schwartz A1 - Caporaso,J Gregory A1 - P Dijkstra A1 - van Gestel,Natasja A1 - BJ Koch A1 - Liu,Cindy M A1 - Hayer,Michaela A1 - McHugh,Theresa A A1 - Jane C Marks A1 - Lance B Price A1 - Hungate,Bruce A KW - Bacteria KW - Biological Evolution KW - Carbon Isotopes KW - Ecology KW - Ecosystem KW - Oxygen Isotopes KW - Phenotype KW - Phylogeny AB -

Phylogeny is an ecologically meaningful way to classify plants and animals, as closely related taxa frequently have similar ecological characteristics, functional traits and effects on ecosystem processes. For bacteria, however, phylogeny has been argued to be an unreliable indicator of an organism's ecology owing to evolutionary processes more common to microbes such as gene loss and lateral gene transfer, as well as convergent evolution. Here we use advanced stable isotope probing with (13)C and (18)O to show that evolutionary history has ecological significance for in situ bacterial activity. Phylogenetic organization in the activity of bacteria sets the stage for characterizing the functional attributes of bacterial taxonomic groups. Connecting identity with function in this way will allow scientists to begin building a mechanistic understanding of how bacterial community composition regulates critical ecosystem functions.

VL - 10 SN - 1751-7362 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=26943624&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 9 ER - TY - JOUR T1 - Plant-herbivore interactions in a trispecific hybrid swarm of Populus: assessing support for hypotheses of hybrid bridges, evolutionary novelty and genetic similarity. JF - The New phytologist Y1 - 2016 A1 - Floate,Kevin D A1 - Godbout,Julie A1 - Lau,Matthew K A1 - Isabel,Nathalie A1 - Whitham,Thomas G KW - Alberta KW - Animals KW - Arthropods KW - biodiversity KW - Biological Evolution KW - Chimera KW - Ecosystem KW - Herbivory KW - Hybridization, Genetic KW - Populus KW - Trees KW - Utah AB -

Natural systems of hybridizing plants are powerful tools with which to assess evolutionary processes between parental species and their associated arthropods. Here we report on these processes in a trispecific hybrid swarm of Populus trees. Using field observations, common garden experiments and genetic markers, we tested the hypothesis that genetic similarities among hosts underlie the distributions of 10 species of gall-forming arthropods and their ability to adapt to new host genotypes.the degree of genetic relatedness among parental species determines whether hybridization is primarily bidirectional or unidirectional; host genotype and genetic similarity strongly affect the distributions of gall-forming species, individually and as a community. These effects were detected observationally in the wild and experimentally in common gardens; correlations between the diversity of host genotypes and their associated arthropods identify hybrid zones as centres of biodiversity and potential species interactions with important ecological and evolutionary consequences. These findings support both hybrid bridge and evolutionary novelty hypotheses. However, the lack of parallel genetic studies on gall-forming arthropods limits our ability to define the host of origin with their subsequent shift to other host species or their evolution on hybrids as their final destination.

VL - 209 SN - 0028-646X UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=26346922&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 2 ER - TY - JOUR T1 - Patterns of phytochemical variation in Mimulus guttatus (yellow monkeyflower). JF - Journal of chemical ecology Y1 - 2013 A1 - Holeski,Liza M A1 - Keefover-Ring,Ken A1 - Bowers,M Deane A1 - Harnenz,Zoe T A1 - Lindroth,Richard L KW - Animals KW - Biological Evolution KW - Butterflies KW - Genetic Variation KW - Glucosides KW - Glycosides KW - Herbivory KW - Larva KW - Mimulus KW - Phenols KW - Phenotype KW - Pheromones KW - Plant Leaves AB -

The search for general patterns in the production and allocation of plant defense traits will be facilitated by characterizing multivariate suites of defense, as well as by studying additional plant taxa, particularly those with available genomic resources. Here, we investigated patterns of genetic variation in phytochemical defenses (phenylpropanoid glycosides, PPGs) in Mimulus guttatus (yellow monkeyflower). We grew plants derived from several natural populations, consisting of multiple full-sibling families within each population, in a common greenhouse environment. We found substantial variation in the constitutive multivariate PPG phenotype and in constitutive levels of individual phytochemicals within plants (among leaves of different ages), within populations (among full-sibling families), and among populations. Populations consisting of annual plants generally, but not always, had lower concentrations of phytochemicals than did populations of perennial plants. Populations differed in their plastic response to artificial herbivory, both in the overall multivariate PPG phenotype and in the individual phytochemicals. The relationship between phytochemistry and another defense trait, trichomes, differed among populations. Finally, we demonstrated that one of the PPGs, verbascoside, acts as a feeding stimulant rather than a feeding deterrent for a specialist herbivore of M. guttatus, the buckeye caterpillar (Junonia coenia Nymphalidae). Given its available genetic resources, numerous, easily accessible natural populations, and patterns of genetic variation highlighted in this research, M. guttatus provides an ideal model system in which to test ecological and evolutionary theories of plant-herbivore interactions.

VL - 39 SN - 0098-0331 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=23468225&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 4 ER - TY - JOUR T1 - Community specificity: life and afterlife effects of genes. JF - Trends in plant science Y1 - 2012 A1 - Whitham,Thomas G A1 - Gehring,Catherine A A1 - Lamit,Louis J A1 - Wojtowicz,Todd A1 - Evans,Luke M A1 - Keith,Arthur R A1 - Smith,David Solance KW - Animals KW - Arthropods KW - Biological Evolution KW - Ecosystem KW - Genotype KW - Herbivory KW - Host-Parasite Interactions KW - Models, Biological KW - Plants KW - Species Specificity AB -

Community-level genetic specificity results when individual genotypes or populations of the same species support different communities. Our review of the literature shows that genetic specificity exhibits both life and afterlife effects; it is a widespread phenomenon occurring in diverse taxonomic groups, aquatic to terrestrial ecosystems, and species-poor to species-rich systems. Such specificity affects species interactions, evolution, ecosystem processes and leads to community feedbacks on the performance of the individuals expressing the traits. Thus, genetic specificity by communities appears to be fundamentally important, suggesting that specificity is a major driver of the biodiversity and stability of the world's ecosystems.

VL - 17 SN - 1360-1385 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=22322002&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 5 ER - TY - JOUR T1 - Relative importance of genetic, ontogenetic, induction, and seasonal variation in producing a multivariate defense phenotype in a foundation tree species. JF - Oecologia Y1 - 2012 A1 - Holeski,Liza M A1 - Hillstrom,Michael L A1 - Whitham,Thomas G A1 - Lindroth,Richard L KW - Animals KW - Biological Evolution KW - Chimera KW - Coleoptera KW - Genetic Variation KW - Herbivory KW - Larva KW - Multivariate Analysis KW - Phenotype KW - Plant Leaves KW - Populus KW - Seasons KW - Trees AB -

Plant adaptations for defense against herbivory vary both among species and among genotypes. Moreover, numerous forms of within-plant variation in defense, including ontogeny, induction, and seasonal gradients, allow plants to avoid expending resources on defense when herbivores are absent. We used an 18-year-old cottonwood common garden composed of Populus fremontii, Populus angustifolia, and their naturally occurring F(1) hybrids (collectively referred to as "cross types") to quantify and compare the relative influences of three hierarchical levels of variation (between cross types, among genotypes, and within individual genotypes) on univariate and multivariate phytochemical defense traits. Within genotypes, we evaluated ontogeny, induction (following cottonwood leaf beetle herbivory), and seasonal variation. We compared the effect sizes of each of these sources of variation on the plant defense phenotype. Three major patterns emerged. First, we observed significant differences in concentrations of defense phytochemicals among cross types, and/or among genotypes within cross types. Second, we found significant genetic variation for within-plant differences in phytochemical defenses: (a) based on ontogeny, levels of constitutive phenolic glycosides were nearly three times greater in the mature zone than in the juvenile zone within one cottonwood cross type, but did not significantly differ within another cross type; (b) induced levels of condensed tannins increased up to 65 % following herbivore damage within one cottonwood cross type, but were not significantly altered in another cross type; and (c) concentrations of condensed tannins tended to increase across the season, but did not do so across all cross types. Third, our estimates of effect size demonstrate that the magnitude of within-plant variation in a phytochemical defense can rival the magnitude of differences in defense among genotypes and/or cross types. We conclude that, in cottonwood and likely other plant species, multiple forms of within-individual variation have the potential to substantially influence ecological and evolutionary processes.

VL - 170 SN - 0029-8549 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=22652923&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 3 ER - TY - JOUR T1 - A genetic basis to community repeatability and stability. JF - Ecology Y1 - 2010 A1 - Keith,Arthur R A1 - JK Bailey A1 - Whitham,Thomas G KW - Animals KW - Arthropods KW - Biological Evolution KW - Ecosystem KW - Genotype KW - Populus AB -

Recent studies have shown that genetically based traits of plants can structure associated arthropod and microbial communities, but whether the effects are consistent and repeatable across years is unknown. If communities are both heritable (i.e., related individuals tend to support similar communities) and repeatable (i.e., the same patterns observed over multiple years), then plant genetics may also affect community properties previously thought to be emergent, such as "stability." Using replicated clones of narrowleaf cottonwood (Populus angustifolia) and examining an arthropod community of 103 species, we found that (1) individual tree genotypes supported significantly different arthropod communities, which exhibited broad-sense heritability; (2) these findings were highly repeatable over three consecutive years (repeatability = 0.91) indicating that community responses to individual tree genotypes are consistent from year to year; (3) differences among tree genotypes in community stability (i.e., changes in community composition over multiple years) exhibited broad-sense heritability (H(C)2 = 0.32). In combination, these findings suggest that an emergent property such as stability can be genetically based and thus subject to natural selection.

VL - 91 SN - 0012-9658 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=21141200&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 11 ER - TY - JOUR T1 - A geographic mosaic of genetic variation within a foundation tree species and its community-level consequences. JF - Ecology Y1 - 2009 A1 - Barbour,Robert C A1 - O'Reilly-Wapstra,Julianne M A1 - De Little,David W A1 - Jordan,Gregory J A1 - Steane,Dorothy A A1 - Humphreys,Jonathon R A1 - JK Bailey A1 - Whitham,Thomas G A1 - Potts,Bradley M KW - Animals KW - Australia KW - Biological Evolution KW - Demography KW - Ecosystem KW - Eucalyptus KW - Fungi KW - Genetic Variation KW - Insecta AB -

Knowledge of the manner in which genetic variation within a tree species affects associated communities and ecosystem processes across its entire range is important for understanding how geographic mosaics of genetic interactions might develop and support different communities. While numerous studies have investigated the community and ecosystem consequences of genetic variation at the hybrid cross type or genotype level within a species, none has investigated the community-level effects of intraspecific genetic variation across the geographic range of a widespread species. This is the scale at which geographic mosaics of coevolution are hypothesized to exist. Studies at this level are particularly important for foundation tree species, which typically support numerous microbial, fungal, plant, and animal communities. We studied genetic variation across eight geographical races of the forest tree Eucalyptus globulus representing its natural distribution across southeastern Australia. The study was conducted in a 15-year-old common garden trial based on families derived from single-tree open-pollinated seed collections from the wild. Neutral molecular genetic variation within E. globulus was also assessed and compared with genetic divergence in the phenotypic and community traits. Three major findings emerged. First, we found significant genetically based, hierarchical variation in associated communities corresponding to geographical races of E. globulus and families within races. Second, divergence in foliar communities at the racial level was associated with genetically based divergence in specific leaf morphological and chemical traits that have known defensive functions. Third, significant positive correlations between canopy community dissimilarity and both neutral molecular genetic and leaf quantitative genetic dissimilarity at the race level supported a genetic similarity rule. Our results argue that genetic variation within foundation tree species has the potential to be a significant driver of the geographical mosaics of variation typical of forest communities, which could have important ecological and evolutionary implications.

VL - 90 SN - 0012-9658 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=19694126&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 7 ER - TY - JOUR T1 - Separating ontogenetic and environmental determination of resistance to herbivory in cottonwood. JF - Ecology Y1 - 2009 A1 - Holeski,Liza M A1 - Kearsley,Michael J C A1 - Whitham,Thomas G KW - Animals KW - Aphids KW - Biological Evolution KW - Ecosystem KW - Feeding Behavior KW - Populus AB -

We used narrowleaf cottonwood, Populus angustifolia, and the gall-forming aphid, Pemphigus betae, to determine the extent to which ontogenetic variation in resistance to herbivory is due to endogenous, stable genetic influences. In a three-year common garden trial using ramets propagated from the top, middle, and bottom of mature trees, we found that the resistance of trees to aphids was significantly higher in top vs. bottom source ramets, supporting the hypothesis of a stable, genetically programmed component to aphid resistance. The magnitude of ontogenetically based variation in resistance within an individual tree is comparable to the genetic variation in resistance among narrowleaf cottonwood genotypes or populations found in other studies. These ontogenetic-based findings have the potential to alter ecological interactions and evolutionary trajectories of plant-herbivore interactions.

VL - 90 SN - 0012-9658 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=19967853&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 11 ER - TY - JOUR T1 - Extending genomics to natural communities and ecosystems. JF - Science Y1 - 2008 A1 - Whitham,Thomas G A1 - DiFazio,Stephen P A1 - Jennifer A Schweitzer A1 - Shuster,Stephen M A1 - Allan,Gery J A1 - JK Bailey A1 - Woolbright,Scott A KW - Animals KW - Biological Evolution KW - Ecosystem KW - Epigenesis, Genetic KW - Genome, Plant KW - Genomics KW - Plant Physiological Phenomena KW - Plants KW - Selection, Genetic KW - Symbiosis AB -

An important step in the integration of ecology and genomics is the progression from molecular studies of relatively simple model systems to complex field systems. The recent availability of sequenced genomes from key plants is leading to a new understanding of the molecular drivers of community composition and ecosystem processes. As genome sequences accumulate for species that form intimate associations in nature, a detailed view may emerge as to how these associations cause changes among species at the nucleotide level. This advance could dramatically alter views about the structure and evolution of communities and ecosystems.

VL - 320 SN - 0036-8075 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=18436780&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 5875 ER -