Abstract Detail


Querns, Aleah [1], Wooliver, Rachel [2], Vallejo-MarĂ­n, Mario [3], Sheth, Seema [1].

The Evolution of Thermal Tolerance and Clines in Native vs. Invasive Populations of Mimulus guttatus.

The rise of globalization has spread organisms beyond their natural range, allowing further opportunity for introduced species to outcompete native inhabitants. Many questions remain about how niche evolution contributes to the success of invasive species. Here, we use thermal performance curves (TPCs) to test the following hypotheses about thermal adaptation during the invasion process. First, in response to strong selection from novel temperature regimes, populations in the invasive range should evolve distinct TPCs relative to native populations. Second, by exhibiting a broad TPC with high maximum performance, invasive species may overcome specialist-generalist tradeoffs, whereby tolerance across a wide range of temperatures comes at the cost of lower peak performance. Third, the presence and steepness of latitudinal and temperature clines in TPC parameters may differ between native and invasive populations due to changes in genetic variation, the strength of temperature-mediated selection, and the time available for adaptation to temperature gradients in the invasive range. To test these hypotheses, we built TPCs for 18 native (United States) and 13 invasive (United Kingdom) populations of the yellow monkeyflower, Mimulus guttatus. We grew clones of multiple genotypes per population across a range of temperatures in growth chambers. We found that invasive populations have not evolved different thermal performance breadth or critical thermal limits, and there were similar specialist-generalist tradeoffs in both native and invasive populations. Native populations did not exhibit clines in TPC parameters, indicating limited thermal adaptation across latitudinal and temperature gradients across the native range. Invasive populations have evolved a higher thermal optimum and exhibited clines in TPC parameters which were absent in native populations, but these clines countered the direction expected based on environmental gradients. Thus, generalist characteristics of source populations and the evolutionary lability of thermal optimum may have promoted the invasion of M. guttatus in the United Kingdom.

1 - North Carolina State Unversity, Department Of Plant And Microbial Biology, Box 7612, Gardner Hall, Raleigh, NC, 27695, United States
2 - North Carolina State University, Department Of Plant And Microbial Biology, Box 7612, Gardner Hall, Raleigh, NC, 27695, United States
3 - University of Stirling, Biological and Environmental Sciences, Stirling, FK9 4LA, Scotland, UK


Presentation Type: Poster
Session: P, Ecology Posters
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 5:00 PM Time and date to be determined
Number: PEC008
Abstract ID:288
Candidate for Awards:Ecological Section Best Graduate Student Poster

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