Ramsey, Justin

• Ph.D., Botany, University of Washington, Seattle, WA 

• B.S., Biology, Whitworth College, Spokane, WA

I am a population biologist who studies the phenotypic and genetic underpinnings of ecological adaptation in plants; this research focuses on non-model study systems, in particular, wild yarrow. The Achillea millefolium aggregate is a circumpolar polyploid complex that occurs in a wide range of climate/soil and shows exceptional phenotypic variability. These plants are easily propagated and experimentally manipulated -- including use in field and garden transplants, which can measure plant performance in contrasting environmental conditions, and controlled crosses, which produce pedigrees segregating for traits of interest. Our work leverages Achillea to tease apart the contributions of genetics and the environment to plant morphogenesis and ecophysiology, addressing longstanding questions about factors underlying complex trait variation and the spatial scales of adaptation. Since 2014, we have studied Achillea populations on a ~250 km elevational transect across the Black Hills and adjoining Great Plains (35 study sites at ~770 - 2,200 m elev., including prairies and badlands, coniferous and deciduous forests, montane grasslands and mountain peaks). Wild populations show 10-fold leaf size variation across this transect while stem lengths and flower numbers exhibit 5- and 3-fold variation, respectively; large plants with luxurious foliage are found in wet meadows and shady forests, while small plants with compact leaves occur in shortgrass prairies and exposed mountain summits. Garden experiments (2016- 2024) indicate a strong genetic component for trait differences (i.e., highly significant correlations in plant size and phenology for populations that are measured in the field vs. garden) which together influence whole-plant physiology and life history strategy (e.g., trade-offs in plant size vs. water use as well as flowering times vs. total flower production). Future work will evaluate ecotype performance (fitness) of the yarrows in contrasting environments and contributions of allelic variation vs. epigenetic changes to phenotypic differences.