@article{wadgymar_sheth_josephs_demarche_anderson_2024, title={Defining Fitness in Evolutionary Ecology}, volume={5}, ISSN={["1537-5315"]}, DOI={10.1086/729360}, abstractNote={Previous articleNext article FreeDefining fitness in evolutionary ecologySusana Wadgymar, Seema N Sheth, Emily B Josephs, Megan L DeMarche, and Jill T AndersonSusana Wadgymar, Seema N Sheth, Emily B Josephs, Megan L DeMarche, and Jill T AndersonPDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmailPrint SectionsMoreDetailsFiguresReferencesCited by International Journal of Plant Sciences Just Accepted Article DOIhttps://doi.org/10.1086/729360 PermissionsRequest permissions Views: 621Total views on this site HistoryAccepted December 26, 2023 © 2024 The University of Chicago. All Rights reserved.PDF download Crossref reports no articles citing this article.}, journal={INTERNATIONAL JOURNAL OF PLANT SCIENCES}, author={Wadgymar, Susana M. and Sheth, Seema and Josephs, Emily and Demarche, Megan and Anderson, Jill}, year={2024}, month={May} } @article{wooliver_vtipilthorpe_wiegmann_sheth_2022, title={A viewpoint on ecological and evolutionary study of plant thermal performance curves in a warming world}, volume={14}, ISSN={["2041-2851"]}, DOI={10.1093/aobpla/plac016}, abstractNote={Abstract}, number={3}, journal={AOB PLANTS}, author={Wooliver, Rachel and Vtipilthorpe, Emma E. and Wiegmann, Amelia M. and Sheth, Seema N.}, year={2022}, month={May} } @article{geyer_kulbaba_sheth_pain_eckhart_shaw_2022, title={Additive genetic variance for lifetime fitness and the capacity for adaptation in an annual plant (vol 73, pg 1746, 2019)}, volume={9}, ISSN={["1558-5646"]}, url={https://doi.org/10.1111/evo.14607}, DOI={10.1111/evo.14607}, abstractNote={,}, journal={EVOLUTION}, author={Geyer, Charles J. and Kulbaba, Mason W. and Sheth, Seema N. and Pain, Rachel E. and Eckhart, Vincent M. and Shaw, Ruth G.}, year={2022}, month={Sep} } @article{sasaki_barley_gignoux-wolfsohn_hays_kelly_putnam_sheth_villeneuve_cheng_2022, title={Greater evolutionary divergence of thermal limits within marine than terrestrial species}, volume={12}, ISSN={["1758-6798"]}, url={https://doi.org/10.1038/s41558-022-01534-y}, DOI={10.1038/s41558-022-01534-y}, abstractNote={There is considerable uncertainty regarding which ecosystems are most vulnerable to warming. Current understanding of organismal sensitivity is largely centred on species-level assessments that do not consider variation across populations. Here we used meta-analysis to quantify upper thermal tolerance variation across 305 populations from 61 terrestrial, freshwater, marine and intertidal taxa. We found strong differentiation in heat tolerance across populations in marine and intertidal taxa but not terrestrial or freshwater taxa. This is counter to the expectation that increased connectivity in the ocean should reduce intraspecific variation. Such adaptive differentiation in the ocean suggests there may be standing genetic variation at the species level to buffer climate impacts. Assessments of vulnerability to warming should account for variation in thermal tolerance among populations (or the lack thereof) to improve predictions about climate vulnerability. The authors quantify the thermal tolerance of 305 populations from 61 taxa by meta-analysis. They reveal strong population-level differentiation in marine and intertidal taxa, but not terrestrial or freshwater taxa, and highlight the need to consider such variation in climate vulnerability predictions.}, number={12}, journal={NATURE CLIMATE CHANGE}, author={Sasaki, Matthew and Barley, Jordanna M. and Gignoux-Wolfsohn, Sarah and Hays, Cynthia G. and Kelly, Morgan W. and Putnam, Alysha B. and Sheth, Seema N. and Villeneuve, Andrew R. and Cheng, Brian S.}, year={2022}, month={Dec}, pages={1175-+} } @misc{wadgymar_demarche_josephs_sheth_anderson_2022, title={Local Adaptation: Causal Agents of Selection and Adaptive Trait Divergence}, volume={53}, ISSN={["1545-2069"]}, url={http://dx.doi.org/10.1146/annurev-ecolsys-012722-035231}, DOI={10.1146/annurev-ecolsys-012722-035231}, abstractNote={ Divergent selection across the landscape can favor the evolution of local adaptation in populations experiencing contrasting conditions. Local adaptation is widely observed in a diversity of taxa, yet we have a surprisingly limited understanding of the mechanisms that give rise to it. For instance, few have experimentally confirmed the biotic and abiotic variables that promote local adaptation, and fewer yet have identified the phenotypic targets of selection that mediate local adaptation. Here, we highlight critical gaps in our understanding of the process of local adaptation and discuss insights emerging from in-depth investigations of the agents of selection that drive local adaptation, the phenotypes they target, and the genetic basis of these phenotypes. We review historical and contemporary methods for assessing local adaptation, explore whether local adaptation manifests differently across life history, and evaluate constraints on local adaptation. }, number={1}, journal={ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS}, publisher={Annual Reviews}, author={Wadgymar, Susana M. and DeMarche, Megan L. and Josephs, Emily B. and Sheth, Seema N. and Anderson, Jill T.}, year={2022}, pages={87–111} } @article{coughlin_wooliver_sheth_2022, title={Populations of western North American monkeyflowers accrue niche breadth primarily via genotypic divergence in environmental optima}, volume={12}, ISSN={["2045-7758"]}, url={https://doi.org/10.1002/ece3.9434}, DOI={10.1002/ece3.9434}, abstractNote={Abstract}, number={10}, journal={ECOLOGY AND EVOLUTION}, author={Coughlin, Aeran O. and Wooliver, Rachel and Sheth, Seema N.}, year={2022}, month={Oct} } @article{querns_wooliver_vallejo-marin_sheth_2022, title={The evolution of thermal performance in native and invasive populations of Mimulus guttatus}, volume={2}, ISSN={["2056-3744"]}, url={https://doi.org/10.1002/evl3.275}, DOI={10.1002/evl3.275}, abstractNote={Abstract}, journal={EVOLUTION LETTERS}, author={Querns, Aleah and Wooliver, Rachel and Vallejo-Marin, Mario and Sheth, Seema Nayan}, year={2022}, month={Feb} } @article{barley_cheng_sasaki_gignoux-wolfsohn_hays_putnam_sheth_villeneuve_kelly_2021, title={Limited plasticity in thermally tolerant ectotherm populations: evidence for a trade-off}, volume={288}, ISSN={["1471-2954"]}, url={https://doi.org/10.1098/rspb.2021.0765}, DOI={10.1098/rspb.2021.0765}, abstractNote={Many species face extinction risks owing to climate change, and there is an urgent need to identify which species' populations will be most vulnerable. Plasticity in heat tolerance, which includes acclimation or hardening, occurs when prior exposure to a warmer temperature changes an organism's upper thermal limit. The capacity for thermal acclimation could provide protection against warming, but prior work has found few generalizable patterns to explain variation in this trait. Here, we report the results of, to our knowledge, the first meta-analysis to examine within-species variation in thermal plasticity, using results from 20 studies (19 species) that quantified thermal acclimation capacities across 78 populations. We used meta-regression to evaluate two leading hypotheses. The climate variability hypothesis predicts that populations from more thermally variable habitats will have greater plasticity, while the trade-off hypothesis predicts that populations with the lowest heat tolerance will have the greatest plasticity. Our analysis indicates strong support for the trade-off hypothesis because populations with greater thermal tolerance had reduced plasticity. These results advance our understanding of variation in populations' susceptibility to climate change and imply that populations with the highest thermal tolerance may have limited phenotypic plasticity to adjust to ongoing climate warming.}, number={1958}, journal={PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES}, author={Barley, Jordanna M. and Cheng, Brian S. and Sasaki, Matthew and Gignoux-Wolfsohn, Sarah and Hays, Cynthia G. and Putnam, Alysha B. and Sheth, Seema and Villeneuve, Andrew R. and Kelly, Morgan}, year={2021}, month={Sep} } @article{preston_wooliver_driscoll_coughlin_sheth_2021, title={Spatial variation in high temperature-regulated gene expression predicts evolution of plasticity with climate change in the scarlet monkeyflower}, volume={12}, ISSN={["1365-294X"]}, url={https://doi.org/10.1111/mec.16300}, DOI={10.1111/mec.16300}, abstractNote={Abstract}, journal={MOLECULAR ECOLOGY}, publisher={Wiley}, author={Preston, Jill C. and Wooliver, Rachel and Driscoll, Heather and Coughlin, Aeran and Sheth, Seema N.}, year={2021}, month={Dec} } @article{a. lee-yaw_l. mccune_pironon_n. sheth_2021, title={Species distribution models rarely predict the biology of real populations}, volume={12}, ISSN={["1600-0587"]}, url={https://doi.org/10.1111/ecog.05877}, DOI={10.1111/ecog.05877}, abstractNote={Species distribution models (SDMs) are widely used in ecology. In theory, SDMs capture (at least part of) species' ecological niches and can be used to make inferences about the distribution of suitable habitat for species of interest. Because habitat suitability is expected to influence population demography, SDMs have been used to estimate a variety of population parameters, from occurrence to genetic diversity. However, a critical look at the ability of SDMs to predict independent data across different aspects of population biology is lacking. Here, we systematically reviewed the literature, retrieving 201 studies that tested predictions from SDMs against independent assessments of occurrence, abundance, population performance, and genetic diversity. Although there is some support for the ability of SDMs to predict occurrence (~53% of studies depending on how support was assessed), the predictive performance of these models declines progressively from occurrence to abundance, to population mean fitness, to genetic diversity. At the same time, we observed higher success among studies that evaluated performance for single versus multiple species, pointing to a possible publication bias. Thus, the limited accuracy of SDMs reported here may reflect the best‐case scenario. We discuss the limitations of these models and provide specific recommendations for their use for different applications going forward. However, we emphasize that predictions from SDMs, especially when used to inform conservation decisions, should be treated as hypotheses to be tested with independent data rather than as stand‐ins for the population parameters we seek to know.}, journal={ECOGRAPHY}, author={A. Lee-Yaw, Julie and L. McCune, Jenny and Pironon, Samuel and N. Sheth, Seema}, year={2021}, month={Dec} } @article{vtipil_sheth_2020, title={A resurrection study reveals limited evolution of phenology in response to recent climate change across the geographic range of the scarlet monkeyflower}, url={https://doi.org/10.1002/ece3.7011}, DOI={10.1002/ece3.7011}, abstractNote={Abstract}, journal={Ecology and Evolution}, author={Vtipil, Emma E. and Sheth, Seema Nayan}, year={2020}, month={Dec} } @article{wooliver_tittes_sheth_2020, title={A resurrection study reveals limited evolution of thermal performance in response to recent climate change across the geographic range of the scarlet monkeyflower}, volume={2}, url={https://doi.org/10.1101/2020.02.14.934166}, DOI={10.1101/2020.02.14.934166}, abstractNote={Abstract}, publisher={Cold Spring Harbor Laboratory}, author={Wooliver, Rachel and Tittes, Silas B. and Sheth, Seema N.}, year={2020}, month={Feb} } @article{wooliver_tittes_sheth_2020, title={A resurrection study reveals limited evolution of thermal performance in response to recent climate change across the geographic range of the scarlet monkeyflower}, volume={74}, url={https://doi.org/10.1111/evo.14041}, DOI={10.1111/evo.14041}, abstractNote={Evolutionary rescue can prevent populations from declining under climate change, and should be more likely at high-latitude, “leading” edges of species’ ranges due to greater temperature anomalies and gene flow from warm-adapted populations. Using a resurrection study with seeds collected before and after a seven-year period of record warming, we tested for thermal adaptation in the scarlet monkeyflower Mimulus cardinalis. We grew ancestors and descendants from northern-edge, central, and southern-edge populations across eight temperatures. Despite recent climate anomalies, populations showed limited evolution of thermal performance curves. However, one southern population evolved a narrower thermal performance breadth by 1.25 °C, which matches the direction and magnitude of the average decrease in seasonality experienced. Consistent with the climate variability hypothesis, thermal performance breadth increased with temperature seasonality across the species’ geographic range. Inconsistent with performance trade-offs between low and high temperatures across populations, we did not detect a positive relationship between thermal optimum and mean temperature. These findings fail to support the hypothesis that evolutionary response to climate change is greatest at the leading edge, and suggest that the evolution of thermal performance is unlikely to rescue most populations from the detrimental effects of rapidly changing climate.}, number={8}, journal={Evolution}, publisher={Wiley}, author={Wooliver, Rachel and Tittes, Silas B. and Sheth, Seema N.}, year={2020}, month={Aug}, pages={1699–1710} } @article{smithers_oldfather_koontz_bishop_bishop_nachlinger_sheth_2020, title={Community turnover by composition and climatic affinity across scales in an alpine system}, volume={107}, ISSN={["1537-2197"]}, DOI={10.1002/ajb2.1376}, abstractNote={PremiseExamining community turnover across climate gradients at multiple scales is vital to understanding biogeographic response to climate change. This approach is especially important for alpine plants in which the relative roles of topographic complexity and nonclimatic or stochastic factors vary across spatial scales.}, number={2}, journal={AMERICAN JOURNAL OF BOTANY}, author={Smithers, Brian V and Oldfather, Meagan F. and Koontz, Michael J. and Bishop, Jim and Bishop, Catie and Nachlinger, Jan and Sheth, Seema N.}, year={2020}, month={Feb}, pages={239–249} } @article{briscoe runquist_gorton_yoder_deacon_grossman_kothari_lyons_sheth_tiffin_moeller_2020, title={Context Dependence of Local Adaptation to Abiotic and Biotic Environments: A Quantitative and Qualitative Synthesis}, volume={195}, ISSN={["1537-5323"]}, DOI={10.1086/707322}, abstractNote={Understanding how spatially variable selection shapes adaptation is an area of long-standing interest in evolutionary ecology. Recent meta-analyses have quantified the extent of local adaptation, but the relative importance of abiotic and biotic factors in driving population divergence remains poorly understood. To address this gap, we combined a quantitative meta-analysis and a qualitative metasynthesis to (1) quantify the magnitude of local adaptation to abiotic and biotic factors and (2) characterize major themes that influence the motivation and design of experiments that seek to test for local adaptation. Using local-foreign contrasts as a metric of local adaptation (or maladaptation), we found that local adaptation was greater in the presence than in the absence of a biotic interactor, especially for plants. We also found that biotic environments had stronger effects on fitness than abiotic environments when ignoring whether those environments were local versus foreign. Finally, biotic effects were stronger at low latitudes, and abiotic effects were stronger at high latitudes. Our qualitative analysis revealed that the lens through which local adaptation has been examined differs for abiotic and biotic factors. It also revealed biases in the design and implementation of experiments that make quantitative results challenging to interpret and provided directions for future research.}, number={3}, journal={AMERICAN NATURALIST}, author={Briscoe Runquist, Ryan D. and Gorton, Amanda J. and Yoder, Jeremy B. and Deacon, Nicholas J. and Grossman, Jake J. and Kothari, Shan and Lyons, Marta P. and Sheth, Seema N. and Tiffin, Peter and Moeller, David A.}, year={2020}, month={Mar}, pages={412–431} } @article{sheth_morueta‐holme_angert_2020, title={Determinants of geographic range size in plants}, url={https://doi.org/10.1111/nph.16406}, DOI={10.1111/nph.16406}, abstractNote={Summary}, journal={New Phytologist}, author={Sheth, Seema Nayan and Morueta‐Holme, Naia and Angert, Amy L.}, year={2020}, month={May} } @article{oldfather_kling_sheth_emery_ackerly_2020, title={Range edges in heterogeneous landscapes: Integrating geographic scale and climate complexity into range dynamics}, volume={26}, url={https://doi.org/10.1111/gcb.14897}, DOI={10.1111/gcb.14897}, abstractNote={Abstract}, number={3}, journal={Global Change Biology}, publisher={Wiley}, author={Oldfather, Meagan F. and Kling, Matthew M. and Sheth, Seema N. and Emery, Nancy C. and Ackerly, David D.}, year={2020}, month={Mar}, pages={1055–1067} } @article{querns_wooliver_vallejo-marín_sheth_2020, title={The evolution of thermal performance in native and invasive populations of Mimulus guttatus}, volume={9}, url={https://doi.org/10.1101/2020.09.10.291252}, DOI={10.1101/2020.09.10.291252}, abstractNote={Abstract}, publisher={Cold Spring Harbor Laboratory}, author={Querns, Aleah and Wooliver, Rachel and Vallejo-Marín, Mario and Sheth, Seema Nayan}, year={2020}, month={Sep} } @article{kulbaba_sheth_pain_eckhart_shaw_2019, title={Additive genetic variance for lifetime fitness and the capacity for adaptation in an annual plant}, volume={73}, url={https://doi.org/10.1111/evo.13830}, DOI={10.1111/evo.13830}, abstractNote={The immediate capacity for adaptation under current environmental conditions is directly proportional to the additive genetic variance for fitness, VA(W). Mean absolute fitness, , is predicted to change at the rate , according to Fisher’s Fundamental Theorem of Natural Selection. Despite ample research evaluating degree of local adaptation, direct assessment of VA(W) and the capacity for ongoing adaptation is exceedingly rare. We estimated VA(W) and in three pedigreed populations of annual Chamaecrista fasciculata, over three years in the wild. Contrasting with common expectations, we found significant VA(W) in all populations and years, predicting increased mean fitness in subsequent generations (0.83 to 6.12 seeds per individual). Further, we detected two cases predicting “evolutionary rescue”, where selection on standing VA(W) was expected to increase fitness of declining populations ( < 1.0) to levels consistent with population sustainability and growth. Within populations, interannual differences in genetic expression of fitness were striking. Significant genotype-by-year interactions reflected modest correlations between breeding values across years (all r < 0.490), indicating temporally variable selection at the genotypic level; that could contribute to maintaining VA(W). By directly estimating VA(W) and total lifetime , our study presents an experimental approach for studies of adaptive capacity in the wild.}, number={9}, journal={Evolution}, publisher={Wiley}, author={Kulbaba, Mason W. and Sheth, Seema N. and Pain, Rachel E. and Eckhart, Vincent M. and Shaw, Ruth G.}, year={2019}, month={Sep}, pages={1746–1758} } @article{lowry_sobel_angert_ashman_baker_blackman_brandvain_byers_cooley_coughlan_et al._2019, title={The case for the continued use of the genus name Mimulus for all monkeyflowers}, volume={68}, ISSN={["1996-8175"]}, DOI={10.1002/tax.12122}, abstractNote={Additional co-authors: Jannice Friedman, Dena L Grossenbacher, Liza M Holeski, Christopher T Ivey, Kathleen M Kay, Vanessa A Koelling, Nicholas J Kooyers, Courtney J Murren, Christopher D Muir, Thomas C Nelson, Megan L Peterson, Joshua R Puzey, Michael C Rotter, Jeffrey R Seemann, Jason P Sexton, Seema N Sheth, Matthew A Streisfeld, Andrea L Sweigart, Alex D Twyford, John H Willis, Kevin M Wright, Carrie A Wu, Yao-Wu Yuan}, number={4}, journal={TAXON}, author={Lowry, David B. and Sobel, James M. and Angert, Amy L. and Ashman, Tia-Lynn and Baker, Robert L. and Blackman, Benjamin K. and Brandvain, Yaniv and Byers, Kelsey J. R. P. and Cooley, Arielle M. and Coughlan, Jennifer M. and et al.}, year={2019}, month={Aug}, pages={617–623} } @article{morueta-holme_oldfather_olliff-yang_weitz_levine_kling_riordan_merow_sheth_thornhill_et al._2018, title={Best practices for reporting climate data in ecology}, volume={8}, url={http://www.nature.com/articles/s41558-017-0060-2}, DOI={10.1038/s41558-017-0060-2}, abstractNote={A large number of published ecological studies fail to include basic information about the climate data used. In the interest of reproducibility and transparency, we offer recommendations for best practices that we urge Editors, authors, and reviewers to adopt in future publications.}, number={2}, journal={Nature Climate Change}, publisher={Nature Publishing Group}, author={Morueta-Holme, Naia and Oldfather, Meagan F. and Olliff-Yang, Rachael L. and Weitz, Andrew P. and Levine, Carrie R. and Kling, Matthew M. and Riordan, Erin C. and Merow, Cory and Sheth, Seema N. and Thornhill, Andrew H. and et al.}, year={2018}, month={Feb}, pages={92–94} } @misc{pain_shaw_sheth_2018, title={Data from "Detrimental effects of rhizobial inoculum early in the life of the partridge pea Chamaecrista fasciculata"}, url={https://conservancy.umn.edu/handle/11299/192838}, DOI={10.13020/D68Q38}, abstractNote={These data files include data on relative growth rate, biomass, and soil moisture from Pain et al. 2018 (American Journal of Botany). See readme file associated with each data file for more information.}, publisher={Data Repository for the University of Minnesota (DRUM)}, author={Pain, Rachel E and Shaw, Ruth G and Sheth, Seema N}, year={2018} } @article{sheth_angert_2018, title={Demographic compensation does not rescue populations at a trailing range edge}, url={https://doi.org/10.1073/pnas.1715899115}, DOI={10.1073/pnas.1715899115}, abstractNote={Significance}, journal={Proceedings of the National Academy of Sciences}, author={Sheth, Seema Nayan and Angert, Amy Lauren}, year={2018}, month={Mar} } @article{pain_shaw_sheth_2018, title={Detrimental effects of rhizobial inoculum early partridge pea, Chamaecrista fasciculata}, volume={105}, ISSN={["1537-2197"]}, url={https://onlinelibrary.wiley.com/doi/abs/10.1002/ajb2.1077}, DOI={10.1002/ajb2.1077}, abstractNote={Premise of the StudyMutualistic relationships with microbes may aid plants in overcoming environmental stressors and increase the range of abiotic environments where plants can persist. Rhizobia, nitrogen‐fixing bacteria associated with legumes, often confer fitness benefits to their host plants by increasing access to nitrogen in nitrogen‐limited soils, but effects of rhizobia on host fitness under other stresses, such as drought, remain unclear.}, number={4}, journal={AMERICAN JOURNAL OF BOTANY}, author={Pain, Rachel E. and Shaw, Ruth G. and Sheth, Seema N.}, year={2018}, month={Apr}, pages={796–802} } @article{sheth_kulbaba_pain_shaw_2018, title={Expression of additive genetic variance for fitness in a population of partridge pea in two field sites}, volume={72}, ISSN={["1558-5646"]}, url={https://doi.org/10.1111/evo.13614}, DOI={10.1111/evo.13614}, abstractNote={Despite the importance of adaptation in shaping biological diversity over many generations, little is known about populations’ capacities to adapt at any particular time. Theory predicts that a population's rate of ongoing adaptation is the ratio of its additive genetic variance for fitness, VA(W) , to its mean absolute fitness, W¯ . We conducted a transplant study to quantify W¯ and standing VA(W) for a population of the annual legume Chamaecrista fasciculata in one field site from which we initially sampled it and another site where it does not currently occur naturally. We also examined genotype‐by‐environment interactions, G × E, as well as its components, differences between sites in VA(W) and in rank of breeding values for fitness. The mean fitness indicated population persistence in both sites, and there was substantial VA(W) for ongoing adaptation at both sites. Statistically significant G × E indicated that the adaptive process would differ between sites. We found a positive correlation between fitness of genotypes in the “home” and “away” environments, and G × E was more pronounced as the life‐cycle proceeds. This study exemplifies an approach to assessing whether there is sufficient VA(W) to support evolutionary rescue in populations that are declining.}, number={11}, journal={EVOLUTION}, publisher={Wiley}, author={Sheth, Seema Nayan and Kulbaba, Mason W. and Pain, Rachel E. and Shaw, Ruth G.}, year={2018}, month={Nov}, pages={2537–2545} } @article{angert_bayly_sheth_paul_2018, title={Testing Range-Limit Hypotheses Using Range-Wide Habitat Suitability and Occupancy for the Scarlet Monkeyflower (Erythranthe cardinalis)}, volume={191}, url={https://doi.org/10.1086/695984}, DOI={10.1086/695984}, abstractNote={Determining the causes of geographic range limits is a fundamental problem in ecology, evolution, and conservation biology. Range limits arise because of fitness and dispersal limitation, which yield contrasting predictions about habitat suitability and occupancy of suitable habitat across geographic ranges. If a range edge is limited primarily by fitness, occupancy of suitable habitat should be high, habitat suitability should decline toward the edge, and no suitable habitat should exist beyond it. In contrast, a range edge limited primarily by dispersal should have unoccupied but suitable habitat at and beyond the edge. We built ecological niche models relating occurrence records for the scarlet monkeyflower (Erythranthe cardinalis) to climatic variables and applied these models to independent data from systematic, range-wide surveys of presence and absence to estimate the availability and occupancy of climatically suitable habitat. We found that fitness limitation predominated over dispersal limitation, but dispersal limitation also played a role at the poleward edge. These results are consistent with the hypothesis that dispersal limitation is more important along shallow environmental gradients and also suggest that synergy between dispersal and fitness limitation can contribute to colonization failure. The framework used here is validated by independent data and could be readily applied to inferring causes of range limits in many other species.}, number={3}, journal={The American Naturalist}, author={Angert, Amy L. and Bayly, Matthew and Sheth, Seema N. and Paul, John R.}, year={2018}, pages={E76–E89} } @article{sheth_angert_2017, title={Demographic compensation does not rescue populations at a trailing range edge}, volume={3}, url={https://doi.org/10.1101/117606}, DOI={10.1101/117606}, abstractNote={ABSTRACT}, number={10}, journal={Proceedings of the National Academy of Sciences of the United States of America}, publisher={Cold Spring Harbor Laboratory}, author={Sheth, Seema Nayan and Angert, Amy Lauren}, year={2017}, month={Mar}, pages={2413–2418} } @article{sheth_angert_2016, title={Artificial selection reveals high genetic variation in phenology at the trailing edge of a species range}, volume={187}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84957824444&partnerID=MN8TOARS}, DOI={10.1086/684440}, abstractNote={Species responses to climate change depend on the interplay of migration and adaptation, yet we know relatively little about the potential for adaptation. Genetic adaptations to climate change often involve shifts in the timing of phenological events, such as flowering. If populations at the edge of a species range have lower genetic variation in phenological traits than central populations, then their persistence under climate change could be threatened. To test this hypothesis, we performed artificial selection experiments using the scarlet monkeyflower (Mimulus cardinalis) and compared genetic variation in flowering time among populations at the latitudinal center, northern edge, and southern edge of the species range. We also assessed whether selection on flowering time yielded correlated responses in functional traits, potentially representing a cost associated with early or late flowering. Contrary to prediction, southern populations exhibited greater responses to selection on flowering time than central or northern populations. Further, selection for early flowering resulted in correlated increases in specific leaf area and leaf nitrogen, whereas selection for late flowering led to decreases in these traits. These results provide critical insights about how spatial variation in the potential for adaptation may affect population persistence under changing climates.}, number={2}, journal={American Naturalist}, author={Sheth, S.N. and Angert, A.L.}, year={2016}, pages={182–193} } @phdthesis{sheth_2014, place={United States -- Colorado}, title={Determinants of geographic distribution in western North American monkeyflowers}, url={https://search.proquest.com/docview/1614530607/abstract/1D0947DD4E2F42F7PQ/1}, school={Colorado State University}, author={Sheth, Seema Nayan}, year={2014} } @article{sheth_jiménez_angert_2014, title={Identifying the paths leading to variation in geographical range size in western North American monkeyflowers}, volume={41}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84939252863&partnerID=MN8TOARS}, DOI={10.1111/jbi.12378}, abstractNote={Abstract}, number={12}, journal={Journal of Biogeography}, author={Sheth, S.N. and Jiménez, I. and Angert, A.L.}, year={2014}, pages={2344–2356} } @article{sheth_angert_2014, title={The evolution of environmental tolerance and range size: A comparison of geographically restricted and widespread mimulus}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84906531223&partnerID=MN8TOARS}, DOI={10.1111/evo.12494}, abstractNote={The geographic ranges of closely related species can vary dramatically, yet we do not fully grasp the mechanisms underlying such variation. The niche breadth hypothesis posits that species that have evolved broad environmental tolerances can achieve larger geographic ranges than species with narrow environmental tolerances. In turn, plasticity and genetic variation in ecologically important traits and adaptation to environmentally variable areas can facilitate the evolution of broad environmental tolerance. We used five pairs of western North American monkeyflowers to experimentally test these ideas by quantifying performance across eight temperature regimes. In four species pairs, species with broader thermal tolerances had larger geographic ranges, supporting the niche breadth hypothesis. As predicted, species with broader thermal tolerances also had more within‐population genetic variation in thermal reaction norms and experienced greater thermal variation across their geographic ranges than species with narrow thermal tolerances. Species with narrow thermal tolerance may be particularly vulnerable to changing climatic conditions due to lack of plasticity and insufficient genetic variation to respond to novel selection pressures. Conversely, species experiencing high variation in temperature across their ranges may be buffered against extinction due to climatic changes because they have evolved tolerance to a broad range of temperatures.}, journal={Evolution}, author={Sheth, S.N. and Angert, A.L.}, year={2014} } @article{sheth_lohmann_distler_jiménez_2012, title={Understanding bias in geographic range size estimates}, volume={21}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84862325044&partnerID=MN8TOARS}, DOI={10.1111/j.1466-8238.2011.00716.x}, abstractNote={ABSTRACT}, number={7}, journal={Global Ecology and Biogeography}, author={Sheth, S.N. and Lohmann, L.G. and Distler, T. and Jiménez, I.}, year={2012}, pages={732–742} } @article{angert_sheth_paul_2011, title={Incorporating Population-Level Variation in Thermal Performance into Predictions of Geographic Range Shifts}, volume={51}, ISSN={1557-7023 1540-7063}, url={http://dx.doi.org/10.1093/icb/icr048}, DOI={10.1093/icb/icr048}, abstractNote={Determining how species' geographic ranges are governed by current climates and how they will respond to rapid climatic change poses a major biological challenge. Geographic ranges are often spatially fragmented and composed of genetically differentiated populations that are locally adapted to different thermal regimes. Tradeoffs between different aspects of thermal performance, such as between tolerance to high temperature and tolerance to low temperature or between maximal performance and breadth of performance, suggest that the performance of a given population will be a subset of that of the species. Therefore, species-level projections of distribution might overestimate the species' ability to persist at any given location. However, current approaches to modeling distributions often do not consider variation among populations. Here, we estimated genetically-based differences in thermal performance curves for growth among 12 populations of the scarlet monkeyflower, Mimulus cardinalis, a perennial herb of western North America. We inferred the maximum relative growth rate (RGR(max)), temperature optimum (T(opt)), and temperature breadth (T(breadth)) for each population. We used these data to test for tradeoffs in thermal performance, generate mechanistic population-level projections of distribution under current and future climates, and examine how variation in aspects of thermal performance influences forecasts of range shifts. Populations differed significantly in RGR(max) and had variable, but overlapping, estimates of T(opt) and T(breadth). T(opt) declined with latitude and increased with temperature of origin, consistent with tradeoffs between performances at low temperatures versus those at high temperatures. Further, T(breadth) was negatively related to RGR(max), as expected for a specialist-generalist tradeoff. Parameters of the thermal performance curve influenced properties of projected distributions. For both current and future climates, T(opt) was negatively related to latitudinal position, while T(breadth) was positively related to projected range size. The magnitude and direction of range shifts also varied with T(opt) and T(breadth), but sometimes in unexpected ways. For example, the fraction of habitat remaining suitable increased with T(opt) but decreased with T(breadth). Northern limits of all populations were projected to shift north, but the magnitude of shift decreased with T(opt) and increased with T(breadth). Median latitude was projected to shift north for populations with high T(breadth) and low T(opt), but south for populations with low T(breadth) and high T(opt). Distributions inferred by integrating population-level projections did not differ from a species-level projection that ignored variation among populations. However, the species-level approach masked the potential array of divergent responses by populations that might lead to genotypic sorting within the species' range. Thermal performance tradeoffs among populations within the species' range had important, but sometimes counterintuitive, effects on projected responses to climatic change.}, number={5}, journal={Integrative and Comparative Biology}, publisher={Oxford University Press (OUP)}, author={Angert, Amy L. and Sheth, Seema N. and Paul, John R.}, year={2011}, month={Jun}, pages={733–750} } @article{paul_sheth_angert_2011, title={Quantifying the impact of gene flow on phenotype- environment mismatch: A demonstration with the scarlet monkeyflower Mimulus cardinalis}, volume={178}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-80053223826&partnerID=MN8TOARS}, DOI={10.1086/661781}, abstractNote={Geographic range margins offer testing grounds for limits to adaptation. If range limits are concordant with niche limits, range expansions require the evolution of new phenotypes that can maintain populations beyond current range margins. However, many species’ range margins appear static over time, suggesting limits on the ability of marginal populations to evolve appropriate phenotypes. A potential explanation is the swamping gene flow hypothesis, which posits that asymmetrical gene flow from large, well-adapted central populations prevents marginal populations from locally adapting. We present an empirical framework for combining gene flow, environment, and fitness-related phenotypes to infer the potential for maladaptation, and we demonstrate its application using the scarlet monkeyflower Mimulus cardinalis. We grew individuals sampled from populations on a latitudinal transect under varied temperatures and determined the phenotypic deviation (PD), the mismatch between phenotype and local environment. We inferred gene flow among populations and predicted that populations receiving the most temperature- or latitude-weighted immigration would show the greatest PD and that these populations were likely marginal. We found asymmetrical gene flow from central to marginal populations. Populations with more latitude-weighted immigration had significantly greater PD but were not necessarily marginal. Gene flow may limit local adaptation in this species, but swamping gene flow is unlikely to explain its northern range limit.}, number={SUPPL. 1}, journal={American Naturalist}, author={Paul, J.R. and Sheth, S.N. and Angert, A.L.}, year={2011} } @article{sheth_loiselle_blake_2009, title={Phylogenetic constraints on fine-scale patterns of habitat use by eight primate species in eastern Ecuador}, volume={25}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-74049151075&partnerID=MN8TOARS}, DOI={10.1017/S0266467409990216}, abstractNote={Abstract:}, number={6}, journal={Journal of Tropical Ecology}, author={Sheth, S.N. and Loiselle, B.A. and Blake, J.G.}, year={2009}, pages={571–582} } @article{sheth_lohmann_consiglio_jiménez_2008, title={Effects of detectability on estimates of geographic range size in Bignonieae}, volume={22}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-38849091349&partnerID=MN8TOARS}, DOI={10.1111/j.1523-1739.2007.00858.x}, abstractNote={Abstract:  Extinction risk has not been evaluated for 96% of all described plant species. Given that the Global Strategy for Plant Conservation proposes preliminary conservation assessments of all described plant species by 2010, herbarium specimens (i.e., primary occurrence data) are increasingly being used to infer threat components from estimates of geographic range size. Nevertheless, estimates of range size based on herbarium data may be inaccurate due to collection bias associated with interspecific variation in detectability. We used data on 377 species of Bignonieae to test the hypothesis that there is a positive relationship between detectability and estimates of geographic range size derived from herbarium specimens. This relationship is expected if the proportion of the true geographic range size of a species that is documented by herbarium specimens is given by the product of the true geographic range size and the detectability of the species, assuming no relationship between true geographic range size and detectability. We developed 4 measures of detectability that can be estimated from herbarium data and examined the relationship between detectability and 2 types of estimates of geographic range size: area of occupancy and extent of occurrence. Our results from regressing estimates of extent of occurrence and area of occupancy on detectability across genera provided no support for this hypothesis. The same was true for regressions of estimated extent of occurrence on detectability across species within genera. Nevertheless, regressions of estimated area of occupancy on detectability across species within genera provided partial support for our hypothesis. We considered 3 possible explanations for this mixed outcome: violation of the assumption of no relationship between true geographic range size and detectability; the relationships between estimated geographic range size and detectability may be an artifact of a negative relationship between estimated area of occupancy and the sampling variance of detectability; detectability may have had 2 opposite effects on estimated species range sizes: one determines the proportion of the true range of a species documented by herbarium specimens and the other determines the distribution of true range size for the species actually observed with herbarium data. Our findings should help improve understanding of the potential biases incurred with the use of herbarium data.}, number={1}, journal={Conservation Biology}, author={Sheth, S.N. and Lohmann, L.G. and Consiglio, T. and Jiménez, I.}, year={2008}, pages={200–211} } @article{sheth_jiménez_consiglio_lohmann_2006, title={Evaluating phylogenetic patterns of threat in Bignonieae (Bignoniaceae) using herbarium data}, url={https://bdpi.usp.br/item/002696357}, journal={Abstracts - Poster}, author={Sheth, Seema N. and Jiménez, Iván and Consiglio, Trisha K. and Lohmann, Lúcia Garcez}, year={2006} } @article{sheth_2006, title={PATTERNS OF HABITAT USE BY PRIMATES IN EASTERN ECUADOR}, volume={41}, url={https://irl.umsl.edu/thesis/41}, journal={Theses}, author={Sheth, Seema}, year={2006}, month={Jun}, pages={146} } @article{amend_meyer-dombard_sheth_zolotova_amend_2003, title={Palaeococcus helgesonii sp, nov., a facultatively anaerobic, hyperthermophilic archaeon from a geothermal well on Vulcano Island, Italy}, volume={179}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0037861947&partnerID=MN8TOARS}, number={6}, journal={Archives of Microbiology}, author={Amend, J.P. and Meyer-Dombard, D.R. and Sheth, S.N. and Zolotova, N. and Amend, A.C.}, year={2003}, pages={394–401} }