Research Areas

Conservation Biology, Evolutionary Biology

Research Interests

Our research takes an integrative approach to study the evolution of natural populations on short timescales. We aim to understand the contributions of different evolutionary forces in shaping patterns of variation across the genome through space and time, and to link genetic variation to variation in individual phenotypes, fitness, and population dynamics. Much of our work is focused on elucidating the consequences of habitat fragmentation and population decline. We address these questions by generating and analyzing large-scale genomic datasets for multi-decade field demographic studies that have accumulated phenotypic and fitness measures for thousands of individuals on multigenerational pedigrees. Our primary study systems include the endangered Florida Scrub-Jay at Archbold Biological Station, North American Red Squirrels at Kluane National Park, and Weddell Seals at Erebus Bay.

Selected Publications

Summers J, Cosgrove EJ, Bakley T, Barve S, Fitzpatrick JW, Chen N. 2026. Sustained multigenerational fitness benefits of natural immigration. bioRxiv doi: 10.64898/2026.05.13.724961.

Cosgrove EJ, Tringali A, Fitzpatrick JW, Bowman R, Clark AG, Chen N. 2025. Genome-wide associations of fitness components reveal antagonistic pleiotropy and sexual conflict in the Florida Scrub-Jay. bioRxiv doi: 10.1101/2025.09.09.673786.

Shah S, Diamond J, Barve S, Cosgrove EJ, Bowman R, Fitzpatrick JW, Chen N. 2024. Lifetime fitness benefits of short-distance dispersal are associated with inbreeding tolerance despite multiple inbreeding avoidance mechanisms. bioRxiv doi: 10.1101/2024.09.21.614049.

Summers J, Cosgrove EJ, Bowman R, Fitzpatrick JW, Chen N. 2024. Density dependence maintains long-term stability despite increased isolation and inbreeding in the Florida Scrub-Jay. Ecology Letters 27: e14483.

Chen N, Juric I, Cosgrove EJ, Bowman R, Fitzpatrick JW, Schoech SJ, Clark AG, Coop GM. 2019. Allele frequency dynamics in a pedigreed natural population. PNAS 116(6): 2158-2164.

Aguillon SM, Fitzpatrick JW, Bowman R, Schoech SJ, Clark AG, Coop GM, Chen N. 2017. Deconstructing isolation-by-distance: The genomic consequences of limited dispersal. PLOS Genetics 13(8): e1006911.

Chen N, Cosgrove EG, Bowman R, Fitzpatrick JW, Clark AG. 2016. Genomic consequences of population decline in the Endangered Florida Scrub-Jay. Current Biology 26: 2974-2979.

Chen N, Van Hout CV, Gottipati S, Clark AG. 2014. Using Mendelian inheritance to improve high throughput SNP discovery. Genetics 198: 847-857.