About

Seema Sheth is an Associate Professor in the Department of Plant and Microbial Biology at North Carolina State University. Her research focuses on evolutionary ecology, investigating how genetic and environmental factors influence plant populations, particularly in response to climate change. Her work involves studying demographic responses, genetic adaptation, phenotypic plasticity, and population persistence across broad geographic and climatic gradients. She employs a combination of long-term demographic data, experimental studies, and genomic analyses to understand how species adapt to changing environments and to predict future population dynamics. Her contributions include evaluating the effects of climate variability on vital rates, assessing the roles of plasticity and genetic adaptation in demographic stability, and developing models to forecast species responses to global change.

Research topics

• Biology
• Ecology
• Artificial Intelligence
• Computer Science
• Sociology
• Evolutionary biology
• Neuroscience
• Demography

Selected publications

• Investigating genetic spillage in a Mimulus cardinalis (syn. Erythranthe cardinalis) common garden experiment

  2026-03-27

  articleOpen access

  Background and Aims Common gardens are critical to studying the trait variations in plant species and how environmental or genetic factors influence them. In common gardens, non-native species and non-local populations must be monitored closely to reduce their chances of escaping, as it can lead to genetic spillage, which is the introduction of foreign genetic material with potential unwanted phenotypes/genotypes into the native ecosystems. This could decrease the fitness of native populations and threaten natural habitats. This study investigated a possible spillage of genetic material from an existing common garden experiment of the Scarlet Monkeyflower. This garden consists of six populations that originated from three regions across its distribution (North, Central, and South), and were propagated at an Ecological Reserve in Southern California. A population of E. cardinalis was spotted a kilometer away from the common garden, leading to the question of whether it is a wild population or an escapee. Methods Leaf samples were collected from individuals of each provenance established at the common garden, as well as the “unknown” population. DNA was extracted from all samples and further processed for DArT sequencing to generate genome-wide SNPs. Genetic clustering analyses such as DAPC, PCoA, and ADMIXTURE were used to determine the genetic proximity of the unknown population against the six provenances from the common garden. Key Results Clustering analyses of all individuals revealed that the unknown population is genetically related to southern populations. A focused analysis of only the southern and unknown populations showed that the unknown individuals formed a distinct cluster, suggesting they are not escapees but represent a natural population in that region. Conclusion Although a spillage was not detected, these findings serve as a reminder for researchers to monitor their garden experiments to control escapees and reduce the possibility of a spillage from occurring.

  PublisherOA PDFDOI

• Rapid evolution predicts demographic recovery after extreme drought

  Science · 2026-03-12 · 4 citations

  article

  Populations that are declining as a result of climate change may need to evolve to persist. Although evolutionary rescue has been demonstrated in theory and in the laboratory, its relevance to natural populations facing climate change remains unknown. Here we link rapid evolution and population dynamics in scarlet monkeyflower, Mimulus cardinalis , during exceptional drought. We leverage whole-genome sequencing across 55 populations to identify climate-associated loci. Simultaneously we track demography and allele frequency change throughout the drought. We establish range-wide population decline during the drought, geographically variable rapid evolution, and variable population recovery that is predictable by standing genetic variation in, and rapid evolution at, climate-associated loci. These findings demonstrate the possibility of evolutionary rescue in the wild, showing that genetic variation at adaptive, but not neutral, loci predicts population recovery.

  PublisherDOI

• Realization of ongoing evolutionary adaptation in the field

  Evolution Letters · 2026-03-25

  articleOpen access

  Abstract The rapid pace of environmental change has prompted pressing concerns about the persistence of wild populations. For plants, because they move from one place to another only passively between generations, their persistence is especially likely to depend on their capacity for ongoing adaptive evolution. There are numerous examples of rapid adaptation in the recent past, but evidence about rates of adaptation in the wild is limited. Previously, to assess the capacity for genetic adaptation of three wild plant populations growing in their source locations, we have estimated their additive genetic variance for fitness in three successive years. Here, we present the actual difference between successive generations in their average absolute fitness. We partition this change into components resulting from genetic change and due to environmental difference, as well as a residual component. In each of six cases of intergenerational change, we have detected evolutionary adaptation as genetic increase in average fitness during the first generation, while also finding generally greater effects of differences in environment between years. Nevertheless, we show that when environmental change reduces a population’s average fitness, these adaptive genetic responses often substantively ameliorate its deleterious impact.

  PublisherDOI

• Rangewide responses of <i>Mimulus cardinalis</i> to an extreme heat event

  American Journal of Botany · 2026-01-14

  articleOpen accessSenior authorCorresponding

  PREMISE: Extreme events are an understudied aspect of ongoing anthropogenic climate change that could play a disproportionate role in the threat that rapid environmental shifts pose to natural populations. METHODS: We exposed plants originating from seeds that were harvested before (ancestors) and after (descendants) multiple extreme heat events from six populations across the range of Mimulus cardinalis (Phyrmaceae) to a short-term heat-wave treatment in controlled growth chamber environments. We assessed physiological, performance, and functional responses (stomatal conductance, leaf temperature deficit, photosystem II efficiency, relative growth rate, specific leaf area, and leaf dry matter content) to the heat-wave treatment, along with evolutionary responses (differences between ancestors and descendants) of M. cardinalis populations to the recent natural extreme heat event. RESULTS: Plants in the heat-wave treatment increased their overall performance, and the magnitude of increase was generally greatest among trailing-edge populations. Despite limited overall trait differences between ancestors and descendants, there was some evidence of divergent evolutionary responses among regions to the natural extreme heat event. However, we did not find evidence of adaptive evolution that affected how M. cardinalis populations responded to the heat-wave treatment. CONCLUSIONS: These results demonstrate that many M. cardinalis populations may reside in environments that are below their optimum average temperature, revealing potential resiliency to future warming. However, limited evolutionary responses in M. cardinalis to the recent extreme heat wave could still indicate potential for future vulnerability to extreme climate events of increased intensity, frequency, and duration.

  PublisherOA PDFDOI

• Limited directional change in mountaintop plant communities over 19 years in western North America

  Ecosphere · 2025-03-01 · 1 citations

  articleOpen accessSenior author

  Abstract Plant communities on mountain summits are commonly long‐lived, cold‐adapted perennials with low dispersal ability. These characteristics in tandem with limited area to track suitable conditions make these mountain communities potentially highly vulnerable to climate change, and indicators of climate change impacts. We investigated temporal changes in plant communities on 29 arid mountain summits across eight study regions in California and Nevada, USA, over 19 years. We analyzed community dynamics in terms of species richness, turnover, gain and loss of functional groups, and relative abundance of functional groups. First, across all summits and regions, we found no change in species richness over time. Second, there was relatively high species turnover (21.7%) between the five‐year survey intervals, but turnover was not significantly different from random expectation. Within functional groups, forbs had the greatest proportion of gains and cushions had the greatest proportion of losses. Third, qualitative abundance categories presented a small but consistent signal of decrease in the relative abundance of cushions, graminoids, and shrubs/trees over the study period. Across a broad geographic scale and nearly two decades, community patterns were widely similar, suggesting that climate change has not impacted local colonization or extirpation of mountaintop species in this arid region. These findings support observed differences in response to climate change between temperature‐limited and water‐limited regions globally, and highlight the lagged and variable nature of high‐elevation systems. Our findings fill a major data gap on alpine plant community responses to climate change in the western United States and bolster the importance of long‐term ecological monitoring with rapid climate change.

  PublisherOA PDFDOI

• Responses to climate change – insights and limitations from herbaceous plant model systems

  2025-03-24 · 1 citations

  preprintOpen accessSenior author

  Herbaceous plant species have been the focus of extensive, long-term research into climate change responses, but there has been little effort to synthesize results and predicted outlooks from different model species. We summarize research on climate change responses for eight intensively-studied herbaceous plant species. We establish generalities across species, examine limitations, interrogate biases, and propose a path forward. All six forb species exhibit reduced fitness, maladaptation, and/or population declines in at least part of the range. Plasticity alone is likely not sufficient to allow adjustment to shifting climates. Most model species also have spatially-restricted dispersal that may limit genetic and evolutionary rescue. These results are surprising, given that these species are widespread, span large elevation ranges, and generally have substantial levels of genetic and phenotypic variation. The focal species have diverse life histories, reproductive strategies, and habitats, but most are native to North America. Thus, these species may poorly represent rare species, habitat specialists, or species endemic to other parts of the world. We encourage researchers to design demographic and field experiments that evaluate plant traits and fitness in contemporary and potential future conditions across the full life cycle, and that consider the effects of climate change on biotic interactions.

  PublisherOA PDFDOI

• Author response for "Linking climate and demography to predict population dynamics and persistence under global change"

  2025-10-27

  peer-review
  PublisherDOI

• Two decades of resurrection studies: What have we learned about contemporary evolution of plant species?

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-07-31 · 5 citations

  preprintOpen access

  Abstract Global change has profoundly altered the eco-evolutionary trajectories of plant species. Longitudinal studies often document phenotypic shifts in response to climate change, such as earlier flowering in the spring, but it remains challenging to disentangle the contributions of phenotypic plasticity and adaptive evolution to shifted phenotypic distributions. The resurrection approach has emerged as a powerful method to study genetic and plastic responses to novel selection imposed by global change by contrasting ancestral and descendant lineages from the same population under common conditions. Here, we compiled a database of 52 resurrection studies to examine key hypotheses about plant evolutionary responses to global change using a meta-analysis (40 of the studies) and quantitative review (all 52 studies). We found evidence for rapid, contemporary evolution, which often appeared adaptive, in over half of the cases, including some of the fastest cases of evolution in natural populations ever observed. Annual plants evolved earlier reproduction, and leaf economic traits associated with stress escape strategies. We also found evolution of increased plasticity for annual plants in phenology and physiology traits, and a reduction of plasticity in traits related to the leaf economic spectrum. We found less evidence for evolution in perennial species. Overall, our findings demonstrate the key role of drought escape in plant responses to a warming world. However, the lack of evolution in other traits and species indicates that constraints may dampen evolutionary responses in some scenarios. Our review also suggests promising avenues of future research for resurrection studies.

  PublisherOA PDFDOI

• Evolutionary responses to historic drought across the range of scarlet monkeyflower

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-05-25 · 4 citations

  preprintOpen access1st authorCorresponding

  Adaptive evolution is a key means for populations to persist under environmental change, yet whether populations across a species' range can adapt quickly enough to keep pace with climate change remains unknown. The breeder's equation predicts the evolutionary change in a trait from one generation to the next as the product of the selection differential and the narrow-sense heritability in that trait. Incorporating these aspects of the breeder's equation, we performed a resurrection study with the scarlet monkeyflower (Mimulus cardinalis) to evaluate whether traits associated with drought adaptation have evolved in populations across a species' range in response to extreme drought. We compared trait and fitness differences of pre-drought ancestors and post-drought descendants from six populations transplanted into three latitudinally-arrayed common gardens and quantified phenotypic selection and trait heritabilities. The strength, direction, and mode of selection varied among traits and gardens. Trait heritabilities were relatively low, and did not differ dramatically among populations or gardens. Overall, instances of evolutionary responses between ancestors and descendants were few and small in magnitude, but the magnitude of these evolutionary differences varied among gardens. Together, these results suggest that the expression of genetic variation, and thus traits, depend on the environment, and that environmental variability in field settings may mask the genetic variation that is often detected in greenhouse environments.

  PublisherOA PDFDOI

• Evolutionary Responses to Historic Drought across the Range of Scarlet Monkeyflower

  The American Naturalist · 2025-09-05 · 3 citations

  article1st authorCorresponding

  ) to evaluate whether traits associated with drought adaptation have evolved in populations across a species' range in response to extreme drought. We compared trait and fitness differences of predrought ancestors and postdrought descendants from six populations transplanted into three latitudinally arrayed common gardens and quantified phenotypic selection and trait heritabilities. The strength, direction, and mode of selection varied among traits and gardens. Trait heritabilities were relatively low and did not differ dramatically among populations or gardens. Overall, instances of evolutionary responses between ancestors and descendants were few and small in magnitude, but the magnitude of these evolutionary differences varied among gardens. These results suggest that evolutionary responses to climate change vary among populations in unpredictable ways and that the expression of these responses depend on environmental conditions, hindering our ability to predict evolutionary rescue under changing climate.

  PublisherDOI

Recent grants

• NSF Postdoctoral Fellowship in Biology FY 2015

  NSF · $138k · 2016–2017

Frequent coauthors

• Amy L. Angert

  University of British Columbia

  33 shared

• Brian V. Smithers

  Montana State University

  15 shared

• Michael J. Koontz

  University of Colorado Boulder

  15 shared

• Meagan F. Oldfather

  University of Colorado Boulder

  9 shared

• Ruth G. Shaw

  University of Minnesota

  9 shared

• Rachel Wooliver

  University of Tennessee at Knoxville

  9 shared

• John R. Paul

  National Institute of Technology Tiruchirappalli

  6 shared

• Mason W. Kulbaba

  Our Lady of the Lake University

  6 shared

Education

• Ph.D., Ecology

  Colorado State University

  2014

• M.S., Biology

  University of Missouri-St. Louis

  2006

• BA, Environmental Studies & Spanish

  Washington University

  2002