Greg ThomGreg Thom

Assistant Professor
SEE Division

2014-2018 - Ph.D., Genetics and Evolutionary Biology, University of São Paulo, São Paulo-SP, Brazil
2010-2013 - M.S., Zoology, Federal University of Para, Belem-PA, Brazil
2006-2010 - B.S. Biology, Regional University of Blumenau, Blumenau-SC, Brazil

Office: 204 Foster Hall
Phone: 681-285-7137                                       

Thom lab

Area of Interest

Tropical regions are hotspots to study speciation due to their diverse biological communities with complex patterns of geographic distribution, and unique ecological attributes. Despite the amazing potential of these regions to explore fundamental questions in evolutionary biology, we are still far from having a comprehensive understanding of the phenotypic traits and genomic underpinnings that allow populations to adapt to heterogeneous environments, and integrate dense species assemblages. My lab has an integrative research program centered on the use of scientific collections that bridge evolution, ecology, and organismal biology to explore the processes driving bird diversification in the Tropics. We develop population genomic studies that link theory with empirical models to produce general insights on the neutral and adaptive mechanisms underlying avian speciation across multiple evolutionary scales, from genomics of species interactions to community-wide patterns of diversification. Our research makes ample use of computational tools, such as supervised machine learning approaches, designed to track genomic signatures of selection, test alternative modes of speciation, and estimate demographic parameters. 

Selected Publications

Smith, B. T.; J. Merwin; K. L. Provost; G. Thom; R. T. Brumfield; M. Ferreira; W. M. Mauck iii; R. G. Moyle; T. Wright; L. Joseph. Phylogenomic analysis of the parrots of the world distinguishes artifactual from biological sources of gene tree discordance. Systematic Biology syac055. 2022. link

Thom, G.; Moreira, L.R.; Batista, R.; Gehara, M.; Aleixo, A.; Smith, B. Genomic architecture controls spatial structuring in Amazonian birds. BioRxiv 2021.12.01.470789 Submission to Molecular Ecology, 2022. link

Musher, L.J.; Giakoumis, M.; Albert, J.; Del Rio, G.; Rego, M.; Thom, G.; Aleixo, A.; Ribas, C.C.; Brumfield, R.T.; Smith, B.T.; Cracraft, J. River network rearrangements promote speciation in lowland Amazonian birds. Science Advances, 2022. link

Thom,‌‌ G.‌; ‌‌Ribas, ‌‌C.; ‌‌Shultz, ‌‌E.; ‌‌Aleixo, ‌‌A.; ‌‌Miyaki, ‌‌C. ‌‌Y. ‌‌Population ‌‌dynamics ‌‌of ‌‌Amazonian ‌‌floodplain‌‌ forest‌‌ specialists ‌‌support ‌‌spatial ‌‌variation ‌‌on ‌‌genetic ‌‌diversity ‌‌but ‌‌not ‌‌range‌ ‌expansions ‌‌through ‌‌time. ‌‌Journal‌‌ of‌‌ Biogeography, 2022 link

Raposo-do-Amaral,‌‌ F.;‌‌ Thom, ‌‌G.‌; ‌‌Lima‐Ribeiro, ‌‌M. ‌‌S.; ‌‌Alvarado‐Serrano, ‌‌D. ‌‌F.; ‌‌Montesanti, ‌‌J. ‌‌A. ‌‌C.;‌‌ Pellegrino,‌ ‌K.;‌‌ Miyaki‌ ‌C.‌‌M.;‌‌ Hickerson,‌ M.‌‌J.;‌‌Maldonado‐Coelho,‌‌M.‌‌ Rugged‌‌ relief,‌ and‌‌ climate‌‌ promote‌‌ isolation‌‌ and‌‌ divergence‌‌ between‌‌ two‌‌ neotropical‌‌ cold‐associated‌‌ birds.‌ Evolution,‌‌ 2021 link

Thom, G.; M. Gehara; Smith, B. T.; Miyaki, C. Y.; Amaral, F. R. Microevolutionary dynamics show tropical valleys are deeper for montane birds of the Atlantic Forest. Nature Communications 12: 6269, 2021 link

Thom, G.; Smith, B. T.; M. Gehara; J. Montesanti; Lima-Ribeiro, M. S. ; Piacentini, V. Q. ; Miyaki, C. Y; Amaral, F. R . Climatic Dynamics And Topography Control Genetic Variation In Atlantic Forest Montane Birds. Molecular Phylogenetics And Evolution, 148 – 106812, 2020. link

Musher, L.; P. Galante; Thom, G.; J. Huntley; M. Blair. Shifting Ecosystem Connectivity During The Pleistocene Drove Diversification And Gene-flow In A Species-complex Of Neotropical Birds (Tityridae: Pachyramphus). Journal Of Biogeography, 106812, 2020. link

Thom, G.; Xue, A. T.; Sawakuchi, A. O.; Ribas, C. C.; Hickerson, M. J.; Aleixo, A.; Miyaki, C. Quaternary Climate Changes As Speciation Drivers In The Amazon Floodplains. Science Advances, V. 6, P. Eaax4718, 2020. link

Silva, S. M. ; Peterson, A. T. ; Carneiro, L. ; Burlamaqui, T. C. T. ; Ribas, C.a C. ; Sousa-neves, T. ; Miranda, L. S. ; Fernandes, A. M. ; D'horta, F. M. ; Araújo-silva, L. E. ; Batista, R. ; Bandeira, C. H. M. M. ; Dantas, S. M. ; Ferreira, M. ; Martins, D. M. ; Oliveira, J. ; Rocha, T. C. ; Sardelli, C. H. ; Thom, G. ; Rêgo, P. S. ; Santos, M. P. ; Sequeira, F. ; Vallinoto, M. ; Aleixo, A. A Dynamic Continental Moisture Gradient Drove Amazonian Bird Diversification. Science Advances, V. 5, P. Eaat5752, 2019. link

Thom, G; Amaral, F R; Hickerson, M J; Aleixo, A; Araujo-Silva, L E; Ribas, C C; Choueri, E; Miyaki, C Y Phenotypic and genetic structure support gene flow generating gene tree discordances in an Amazonian floodplain endemic species. Systematic Biology, 67: 700-718, 2018. link

Amaral, F R; Maldonado-Coelho, M; Aleixo, A; Luna, L W; Rego, P; Araripe, J; Souza, T O; Silva, W A G; Thom, G. Recent chapters of neotropical history overlooked in phylogeography: shallow divergence explains phenotype and genotype uncoupling in Antilophia manakins. Molecular Ecology, 27: 4108-4120, 2018. *Journal Cover link

Choueri, É L; Gubili, C; Borges, S H; Thom, G; Sawakuchi, AO; Soares, E A A; Ribas, C C. Phylogeography and population dynamics of antbirds (Thamnophilidae) from amazonian fluvial islands. Journal of Biogeography, 47:2284-2294, 2017. link

Thom, G; Aleixo, A. Cryptic speciation in the white-shouldered antshrike (Thamnophilus aethiops, Aves - Thamnophilidae): the tale of a transcontinental radiation across rivers in lowland Amazonia and the northeastern Atlantic forest. Molecular Phylogenetics And Evolution, 82: 95-110, 2015. link