Climate-Driven Evolution: Exploring Genetic Diversity, Range Shifts, and Dispersal in Terrestrial Mammals
Why do some species maintain stable ranges while others undergo drastic shifts? What roles do genetic diversity and life history traits play in shaping these responses?
My PhD research explores these questions by focusing on terrestrial mammals in North America. I investigate how spatial patterns of genetic diversity are changing under climate stress and how those changes relate to species' generation length—a key life history trait. To address this, I use both empirical and theoretical approaches.
By integrating genetic, ecological, and climatic data, my work aims to uncover how biodiversity is structured across space and time—and how it may shift in the future. Ultimately, this research contributes to a deeper understanding of eco-evolutionary dynamics under global change, with implications for conservation planning, climate adaptation strategies, and predicting species persistence in rapidly changing environments.
Evolutionary Affinities within the Genus Ratufa Revealed Through Genetic and Phenotypic Markers
How do evolutionary history and environmental gradients shape patterns of diversity within a threatened mammalian lineage?
As part of my undergraduate research, I investigated the phylogenetic relationships and phenotypic variation within the genus Ratufa, a group of giant arboreal squirrels considered “living fossils.” I reconstructed the phylogeny of all four extant species—including all three subspecies of Ratufa macroura—using mitochondrial DNA sequences (cytochrome b and 12S regions), and applied both maximum likelihood and Bayesian inference methods. The results revealed two major clades corresponding to body coloration: a lighter clade (R. macroura, R. affinis) and a darker clade (R. indica, R. bicolor), supporting the monophyly of the genus and clarifying evolutionary affinities.
In parallel, I conducted a detailed analysis of morphological traits—such as coat coloration, vocalization, and hair structure—across R. macroura populations in Sri Lanka. I tested whether phenotypic divergence resulted from local adaptation to environmental gradients or from genetic drift via isolation-by-distance. The variation was largely clinal and strongly correlated with rainfall, suggesting ecological selection plays a key role. Notably, R. m. melanochora—inhabiting the wet zone—exhibited the most distinct morphology, potentially due to selection on pigmentation genes like Mc1r.
This research deepened understanding of how evolutionary forces shape both genetic and phenotypic diversity in endemic mammals, and provided insights relevant to conservation, taxonomy, and biogeography in tropical South Asia.
Skills learned
Collected and processed tissue and hair samples from wild and captive R. macroura populations (n=18)
Extracted DNA, conducted PCR, and performed phylogenetic analysis together with sequences from GenBank using RAxML and MrBayes.
Measured cranial and morphometric measurements (n=61) from museum specimens and retrieved records from collection directories.
Conducted statistical analyses on biometric data, including regression, correlation, and principal component analysis (PCA).
Captured and analyzed vocalizations of wild R. macroura in Raven Pro.
Analyzed coat coloration via spectrophotometry using MATLAB and CLR.
Integrated climatic and topographic data into spatial analyses.
Examined hair microstructure across body regions under microscopy for taxonomic comparison.
Related Conference Papers
Pathirana, K., & Seneviratne, S. S. (2021, April). Evolutionary affinities of the melanistic Grizzled Giant Squirrel of Sri Lanka. Paper presented at the Annual Session of the Department of Wildlife Conservation, Colombo, Sri Lanka.
Pathirana, K., & Seneviratne, S. S. (2021, January). Wet climate drives melanistic giant squirrel (Ratufa macroura melanochora) in wet zone of Sri Lanka. Paper presented at the International Forestry and Environment Symposium 2020, Colombo, Sri Lanka.
Pathirana, K., & Seneviratne, S. S. (2020, September). Phylogenetic history of the genus Ratufa (giant squirrels) in tropical Asia. Paper presented at the conference Using the Resilience of Nature to Face the Reality of Climate Change, Colombo, Sri Lanka.
Research Awards
_______________2025
Ray C. Anderson Fellowship
University of Minnesota
Awarded to graduate students conducting genetics-related research for their dissertation.
_______________2021
Dayton Bell Museum Fund
Bell Museum
Awarded to graduate students conducting research in the field of natural history.
Certificate of Commendation for Undergraduate Research
Sri Lanka Natural History Society
Recognized for outstanding undergraduate research in zoology.
Best Oral Presenter
International Forestry and Environment Symposium
Awarded for the best oral presentation: Wet climate drives melanistic giant squirrel (Ratufa macroura melanochora) in the wet zone of Sri Lanka.
_______________2020
Gulamhusein A.J. Noorbhai Gold Medal
University of Colombo, Sri Lanka, 2020
Awarded for the best undergraduate research project in zoology.
Academic & Professional Development Awards
_______________2026
EEB Research Award
University of Minnesota
Awarded to support graduate-level technical training related to the dissertation research project
_______________2025
EEB Travel and Tuition Award
University of Minnesota
Awarded to support graduate-level professional training with a focus on teaching development.
EEB Spring Research Funding
University of Minnesota
Awarded to support the professional development and research activities of graduate students.
_______________2017
Keertisinghe Memorial Award
University of Colombo, Sri Lanka
Awarded for achieving the highest academic results in zoology in the B.Sc. degree program.
Gulamhusein A.J. Noorbhai Scholarship
University of Colombo, Sri Lanka
Scholarship awarded to the top-performing student entering the Zoology honors degree program.
Museum-Based Experience
Bell Museum of Natural History, University of Minnesota | 2021-2022
Conducted craniological measurements on Peromyscus species to investigate morphological variation.
Extracted and integrated morphological records from GBIF, Arctos, VertNet, and local museum databases.
Manually georeferenced over 500 Ratufa specimens housed in North American natural history collections.
Managed and cleaned large-scale specimen datasets for downstream ecological and evolutionary analyses.
National Museum of Sri Lanka | 2019
Measured skin coloration and craniological traits from Ratufa macroura specimens for comparative morphological research.
Digitized and extracted data from museum directories and specimen catalogs.
Research Mentorship & Review
Undergraduate Research Mentor
Department of Ecology, Evolution, and Behavior, UMN | Fall 2024 – Spring 2025
Mentored Brooklyn Lennes, a senior majoring in EEB, on her research project focusing on the Spatial Distribution and Biogeography of Mustelids. Held weekly meetings, guided her in using natural history archives, and assisted with data management, cleaning, and spatial visualization.
Undergraduate Research Proposal Reviewer
College of Biological Sciences, UMN | 2025
Reviewed proposals submitted to the Undergraduate Research Opportunities Program (UROP), which provides semester-long funding for student-led research projects.
Technical Skills & Analytical Training
_______________2026
Project Management 010
Graduate School, UMN
Learned core project management concepts through hands-on practice and gained experience with Work Breakdown Structures, project scheduling (including critical path and triple constraints), and the difference between cost estimating and budgeting. See Credentials: Maroon Badge, Gold Badge
Working With Zebrafish (Danio rerio) in Research Settings
CITI Program
Learned the principles of working with zebrafish in research settings, explored their biology, husbandry, water quality management, handling, anesthesia, and euthanasia, and gained an understanding of regulatory and safety considerations for their ethical use in research. See Credentials
Working With Fish in Research Settings
CITI Program
Learned the principles of working with fish in research settings, explored their biology, humane care standards, handling, anesthesia, surgery, and euthanasia, and completed all modules with a focus on minimizing pain and distress. See Credentials
Animal Use Tutorial
Office of VP for Research, UMN
Learnt basics about the ethical treatment of animals, what to know about doing research at the University of Minnesota, and training information specific to biomedical, agricultural, or wildlife research.
ROHP Introductory Training
University Health and Safety, UMN
Gained knowledge about zoonotic diseases, tetanus, and gastrointestinal diseases, as well as animal allergens. Explored symptoms and basic preventative measures.
_______________2025
Best Foot Forward! Skills for Presenting Yourself & Your Research
Graduate School, UMN
Learned and developed skills to present myself and my research clearly, persuasively, and confidently by strengthening research storytelling, slide design, interview communication, and job-talk preparation through workshops, peer reflection, and engagement with the Three-Minute Thesis (3MT) competition. See credentials
Research Presentation as Storytelling
Graduate School, UMN
Through lectures and hands-on activities, I learned how to approach research presentations as storytelling. I can now think about my presentations in terms of narrative, apply storytelling principles to my research, and craft talks that are engaging and story-driven. See credentials
Fundamentals for Using Hyperspectral and Thermal NASA Earth Observation Data
NASA
Learnt the fundamentals of hyperspectral and thermal imaging, and explored how to access, visualize, and apply VSWIR and TIR datasets for Earth science research using cloud-based tools.
Integrating Mechanisms in Biogeography with Microclimate and Biophysical Models
International Biogeography Society
Worked through the full pipeline of modeling a terrestrial species’ spatial distribution using mechanistic biogeography software and microclimate models.
Interactive Maps in R
Physalia Courses
Gained hands-on experience in creating interactive, publication-ready maps using R.
High-Performance Computing Use Badge
Minnesota Supercomputing Institute
Learned how to connect to remote cyberinfrastructure, schedule compute jobs on shared clusters, and operate within a command-line interface for large-scale computing. See credentials
Phylogenetic Comparative Methods in R
Physalia Courses
Explored how to generate ultrametric phylogenies and apply phylogenetic comparative methods to investigate trait and lineage evolution using R.
Species Distribution Modeling in R with the sdm Package
International Biogeography Society
Trained in the SDM framework for fitting correlative, mechanistic, and agent-based species distribution models at individual and community scales.
Using Microclimate Data and Models for Ecological Implications
International Biogeography Society
Trained in extracting and modeling microclimate data to mechanistically predict the thermal environment of terrestrial mammals using ecological modeling tools in R.
_______________2024
GIS and Spatial Analysis Workshop
SEEDS Program, Ecological Society of America
A five-day hands-on workshop focused on geospatial tools and spatial data applications in ecological research.
_______________2021
Writing in the Sciences
Stanford University
Learned to become more effective writers through practical examples and exercises focused on clarity, structure, and efficiency. Topics included principles of good writing, strategies for faster writing with less anxiety, scientific manuscript formats, peer review, grant writing, ethics in publishing, and writing for general audiences. See Credentials
_______________2019
Taxonomy and Phylogeny
Sri Lanka Association for the Advancement of Science
Introduced to taxonomic principles across taxa and approaches to reconstructing phylogenies in evolutionary biology.
Field Workshops
_______________2018
National Bird Ringing Program — Mannar Island, Sri Lanka
Participated in field-based bird banding and monitoring efforts as part of a national-scale avian research initiative.
_______________2017
Beginners’ Workshop for Birding — Sinharaja Rainforest, Sri Lanka
Introduced to tropical bird identification, behavioral observation, and fundamental ornithological field techniques during a five-day rainforest immersion.
Bird Study Field Techniques Workshop — Field Ornithology Group of Sri Lanka (FOGSL), Rajarata University
A four-day workshop on avian field research methods, data recording, and survey design.
Field Training Related Courses
The best training I received as a field biologist was during my undergraduate years at the University of Colombo. From tropical rainforests to marine national parks, I gained hands-on experience across diverse landscapes in Sri Lanka—conducting wildlife surveys, species identification, and behavioral observations under the guidance of incredible mentors. I learned not only field techniques but also how to navigate challenges, adapt on the go, and respect the unpredictability of the wild—including what to do, and what not to do. These experiences shaped me into a more grounded, resilient scientist and human being and left me with skills, stories, and life lessons that continue to guide my path.
_______________2016
ZL 1009 – Evolution and Biogeography
Learned how to conduct field biodiversity surveys and species identification.
Conducted a butterfly diversity survey at Anawilundawa Wetland Sanctuary.
ZL 1010 – Animal Behavior
Gained skills in behavioral observation and ethogram development.
Conducted behavioral analyses of elephants at Pinnawala Elephant Orphanage.
_______________2017
ZL 2009 – Principles of Ecology
Performed demographic analysis of invertebrates, determining sex ratios of crabs and mollusks in a selected site of Attaragoda Wetland.
Learned wetland bird observation techniques, including constructing hides, identifying wetland bird species at Bundala National Park, and standard data recording methods.
_______________2018
ZL 3018 – Animal and Human Parasites
Learned parasitological sampling and fecal analysis techniques.
Conducted fecal analysis on selected captive species at the National Zoological Gardens of Sri Lanka.
ZL 3069 – Fundamentals of Conservation Biology and Wildlife Management
Trained in mammal survey techniques, including direct (visual) and indirect (pellets, tracks, calls, signs) methods; conducted in Kumana National Park.
Learned stakeholder analysis for wildlife management, considering social and ecological needs of local communities; fieldwork held in Wasgamuwa National Park.
ZL 3071 – Animal Kingdom I
Trained in insect sampling and identification methods.
Collected and surveyed dragonflies and damselflies in the Gilimale Forest Reserve.
ZL 3074 – Animal Kingdom II
Learned methods for bird identification and observation of mixed-species foraging flocks in Sinharaja Rainforest.
Trained in handling and identification of amphibians and snakes during fieldwork at Maduru Oya National Park.
_______________2019
ZL 4063 – Ornithology
Learned mist-netting, biometric data collection, and temporal behavioral observations of birds in Sinharaja Rainforest.
Studied nesting behavior of ground-nesting birds and mist-netting of woodland birds at Adam’s Bridge Marine National Park.
ZL 4065 – Wildlife Management
Surveyed how animal abundance varies with human settlement patterns by comparing two trails (forest-covered and paved) along Adam’s Peak.
Field-Based Experience
Served as a Research Assistant (2018–2021) in a PhD project on avian migration in the Central Asian Flyway at the University of Colombo. Contributed to field research on migratory waders, including bird ringing, satellite tagging, and field data collection to study stopover dynamics and regional connectivity.
Worked as a Research Assistant (2019–2020) on a PhD project investigating gene flow and vocal plasticity in the Dicrurus (drongo) species complex. Field responsibilities included mist-netting and bioacoustic recording for analyses of vocal divergence and hybridization across contact zones.