About Me

Photo of Alayna in a blue shirt standing in front of some trees

As an evolutionary plant biologist focused on climate adaptation, I seek to understand plant responses to the environment across time scales – plastic responses across days, seasons, or years; and evolutionary responses across generations, populations, and species.

I am currently an NSF Plant Genome Postdoctoral Fellow, working with Jill Hamilton at Penn State University. I completed my PhD in 2023 with Victoria Sork at UCLA.

Research Interests

My work focuses on understanding the mechanisms of evolution both for the insight it provides into natural history and as a tool for conserving plants under rapidly changing climates. Forest trees are often foundational species in ecosystems, and their life history characteristics - long lifespans, high gene flow, and high genetic diversity - make them interesting subjects for studying evolution. My research includes both model species (Populus, poplars or cottonwoods) and non-model species (Quercus, oaks), as well as both common and endangered species. My work is rooted in genomic methods, but I believe that genomics is most useful when genetic variation can be linked to its phenotypic significance, so I also incorporate measurements of functional and ecophysiological traits.

Publications

  1. Mead A, Medeiros CD, Ochoa ME, Sack L, Sork V. 2025. Drought tolerance is associated with constitutive gene expression, not plasticity, across California oak species. bioRxiv. 2025:2025-08

  2. Mead A, Beasley-Bennett JR, Bleich A, Fischer D, Flint S, Golightly J, Klopf SK, Kulbaba MW, Lasky JR, LeBoldus JM, Lowry DB, Mitchell N, Moran E, Sexton JP, Søndreli KL, Worthing B, Zavala-Paez M, Fitzpatrick MC, Holliday J, Keller S, and Hamilton JA. 2025. Variation in responses to temperature across admixed genotypes of Populus trichocarpa × P. balsamifera predict geographic shifts in regions where hybrids are favored. bioRxiv: 2025.05.16.654548.

  3. Buck R, Mead A, Fitz-Gibbon S, Sork V. 2025. Ancient introgression shapes the evolutionary history of a California Channel Island relictual species, island oak (Quercus tomentella). Global Ecology and Conservation: e03706. PDF

  4. Mead A, Fitz-Gibbon S, Knapp J, Sork V. 2025. Comparison of conservation strategies for California Channel Island Oak (Quercus tomentella) using climate suitability predicted from genomic data. Evolutionary Applications: 17(12), e70057. PDF

  5. Mead A*, Di Santo LN*, Wright JW, Hamilton JA. 2025. Genetic basis of reproductive isolation in Torrey pine (Pinus torreyana Parry): insights from hybridization and adaptation. Evolutionary Applications 18(4): e70094 (*contributed equally). PDF

  6. Mead A, Fitz-Gibbon ST, Escalona M, Beraut E, Sacco S, Marimuthu MPA, Nguyen O, Sork VL. 2024. The genome assembly of Island Oak (Quercus tomentella), a relictual island tree species. Journal of Heredity: esae002. PDF

  7. Fitz-Gibbon S, Mead A, O’Donnell S, Li Z-Z, Escalona M, Beraut E, Sacco S, Marimuthu MPA, Nguyen O, Sork VL. 2023. Reference genome of California walnut, Juglans californica, and resemblance with other genomes in the order Fagales. Journal of Heredity 114: 570–579. PDF

  8. Browne L, Mead A, Horn C, Chang K, Celikkol ZA, Henriquez CL, Ma F, Beraut E, Meyer RS, Sork VL. 2020. Experimental DNA Demethylation Associates with Changes in Growth and Gene Expression of Oak Tree Seedlings. G3 Genes|Genomes|Genetics 10: 1019–1028. PDF

  9. Mead A, Ramirez JP, Bartlett MK, Wright JW, Sack L, Sork VL. 2019. Seedling response to water stress in valley oak (Quercus lobata) is shaped by different gene networks across populations. Molecular Ecology 28: 5248–5264. PDF