Dr. Seth Newsome

Professor of Biology and Associate Director UNM Center for Stable Isotopes
My research has three overarching foci. First, I quantify niche breadth at multiple levels of biological organization –– individuals to communities –– to better understand the energetic basis of community assembly and structure. Second, I use controlled feeding experiments in which I vary the chemical composition and concentrations of dietary macromolecules to understand how animals process protein, lipids, and carbohydrates. This enables me to trace energy flow within organisms at the molecular level, which provides insights into which exogenous and endogenous resources are used to maintain homeostasis. Third, I often adopt a deep temporal perspective that compares species interactions in modern and ancient ecosystems to provide unique data on the full range of animal behavioral and ecological flexibility. Such information is important for designing effective long-term management and conservation strategies. Besides science, I enjoy mountain biking, rafting, fly fishing, and have a soft spot in my heart for old school hip-hop.

[email protected]

Lab Members


Dr. Geraldine Busquets Vass

I am interested in understanding the foraging ecology and reproductive physiology of marine megafauna via analysis of intrinsic biomarkers in animal tissues. During my Ph.D. at CICIMAR-IPN (La Paz, Mexico), I studied the foraging ecology, movement patterns, and physiology of blue whales using stable isotope analysis in metabolically active (skin) and inert (baleen) tissues. My postdoctoral research is sponsored by CONACYT and will characterize the foraging ecophysiology and migratory patterns of blue, gray, fin, and humpback whales in the eastern Pacific Ocean using bulk tissue and amino acid isotope analysis of baleen plates. This study will enable us to assess the vulnerability of baleen whales to environmental change that we anticipate will inform species-specific management plans.

[email protected]

Joshua Cortez

Ph.D. Student
I am interested in consumer-resource interactions in stochastic environments, specifically how community assembly is impacted by the behavioral decisions of rodents in desert ecosystems. Using novel techniques that track hundreds of individual rodents simultaneously, my projects aim to tease out which ecological factors are most important to foraging decisions and the impact of those decisions on individual body condition and survival. Further, I am interested in ecosystem engineering and am combining rodent behavioral and net primary production data to study the top down impacts of small mammals on plant communities. Currently, these projects are being pursued in an ecotone between creosote shrubland and black grama grassland at the Sevilleta National Wildlife Refuge in central New Mexico.

[email protected]
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Alana Robinson

CSI Technician
I am interested in the metabolic adaptations used by organisms to maintain homeostasis, especially under conditions of extreme stress. I am also interested in how this intersects with conservation, microbiology, and immunology. While pursuing my undergraduate degree in biochemistry, I used stable isotope analysis of individual amino acids to examine differences in sea otter protein metabolism between tissue types. I am currently collaborating with researchers at the UNM Cancer Center on a study using amino acid isotope analysis to explore the metabolism of brain tumors (glioblastoma). As a technician at the UNM Center for Stable Isotopes I prepare and analyze samples, perform outreach to students, and assist with graduate research. In the future, I hope to continue with interdisciplinary biochemical research at the graduate level.

[email protected]

Conner Mertz

Ph.D. Candidate
I am fascinated by the complexity and elegance of how cells maintain homeostasis, respond to stress and defend themselves against infectious agents. I am particularly interested in the interactions between microbes and their hosts. Since all animals host microbes in their gut, I plan to look at the gut microbiome’s impact on host physiology and protein metabolism. My graduate research integrates two fields, next-generation genetic analysis and amino acid isotope analysis, to describe the community composition of the gut microbiome while also exploring the role microbes play in the synthesis of amino acids used by the host. Host-microbe interactions range from mutualistic to pathogenic, therefore understanding these interactions are integral to our understanding of health and disease.

[email protected]
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Anejelique Martinez

M.Sc. Student
I am interested in the function of the gut microbiome in wild mammals, specifically how it intersects with conservation, microbiology, and the impact of humans on the natural world. My graduate research aims at understanding the interactions between prokaryotic and eukaryotic microbes and their hosts in a community of small mammals inhabiting a desert ecosystem at the Sevilleta National Wildlife Refuge in central New Mexico. I will use a combination of amino acid isotope and 16/18s genetic analysis to understand the functional role of the gut microbiome in host protein metabolism. The study of host-microbe will be integral to our understanding of species interactions and the importance of how an intrinsic source of (brown) microbial energy influences consumer resource selection.

[email protected]
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Rachel Seddon

Ph.D. Student
I am interested in the trophic dynamics of aquatic food webs, specifically how microplankton influence the movement of energy through aquatic ecosystems and their influence on biogeochemical cycling. Along with the Newsome Lab, I am also affiliated with the McMurdo Long-Term Ecological Research Site in the McMurdo Dry Valleys of Victoria Land, Antarctica. My research combines next-generation genetic sequencing and amino acid isotope analysis to study the ecological role of globally ubiquitous mixotrophic protists within the paleo-lakes of the McMurdo Dry Valleys. I aim to provide new insights into the impact that aquatic mixotrophic microbes have on trophic dynamics and the biological carbon pump with the hope of enabling more accurate predictions of how marine ecosystems will respond to climate change.

[email protected]
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Caitlin Zimmer

M.Sc. Student
I am interested in researching the factors that influence food web dynamics and community connectivity within marine environments. Understanding these ecological interactions is an essential first step to understanding what makes an ecosystem resilient and how this resiliency will be affected by natural and anthropogenic stressors. For my masters, I aim to use amino acid nitrogen isotope analysis to investigate how pelagic predator communities respond to shifts in ocean conditions and prey abundance, focusing specifically on food chain length and the linkages between epipelagic and mesopelagic food webs. Before beginning my graduate school journey, I was a marine ecology teacher at The Island School in the Bahamas. This has inspired me to want to communicate the diverse applications of stable isotope analysis to the wider public in everyday language.

[email protected]

Dr. Philip J. Manlick (Postdoc): Research Biologist, U.S. Forest Service (Juneau, AK)

Dr. Oliver Shipley (Postdoc): Research Assistant Professor, Stony Brook University (Stony Brook, NY)

Dr. John P. Whiteman (Postdoc): Assistant Professor, Old Dominion University (Norfolk, VA)

Dr. Christy J. Mancuso (Postdoc): Thermo Scientific (Albany, NY)

Dr. Nico Lubcker (Postdoc)

Dr. Emma A. Elliott Smith (Ph.D.): Postdoctoral Associate, Smithsonian Institution (Washington, DC)

Dr. Alexi C. Besser (Ph.D.): Postdoctoral Associate, Arizona State University (Tempe, AZ)

Deborah Boro (M.Sc.): Natural Heritage New Mexico (Albuquerque, NM)

Laura Pages Barcelo (M.Sc.): Bosque Ecosystem Monitoring Program (Albuquerque, NM)

Christina Blevins (M.Sc.): Sandia National Laboratory (Albuquerque, NM)

Jessica Johnson (M.Sc.): Los Alamos National Laboratory (Los Alamos, NM)

Dr. Rodrigo Bastos: Postdoctoral Fellow, Universidade Federal de Pernambuco (Recife, Brazil)

Juliano Coletto: Ph.D. Student, Universidade Federal do Rio Grande (Rio Grande, Brazil)

Andre Costa Pereira: Ph.D. Student, Universidade de Brasilia (Brasilia, Brazil)

Dr. Marilyn L. Fogel: Distinguished Professor and EDGE Director, UC Riverside (Riverside)

Michael Fox: Ph.D. Candidate, Scripps Institute of Oceanography (La Jolla)

Sean Hixon: Ph.D. Student, Pennsylvania State University (College Station)

Dr. Rocio Loizaga de Castro: Research Professor, Centro Nacional Patagonico (Puerto Madryn, Argentina)

Dr. Paul L. Koch: Distinguished Professor and Dean, UC Santa Cruz (Santa Cruz)

Sabina Llamazares: Ph.D. Student, Universidad de Buenos Aires (Buenos Aires, Argentina)

Nico Lubcker: Ph.D. Candidate, University of Pretoria (Pretoria, South Africa)

Dr. Karin Maldonado: Research Professor, University of Chile (Santiago, Chile)

Natasha Phillips: Ph.D. Candidate, Queens University (Belfast, Northern Ireland)

Dr. Francisca Santana: Postdoc, Universidad de Antofagasta (Antofagasta, Chile)

Juliann Schamel: Biologist, Channel Islands National Park (Ventura)

Clarissa Teixeira: Ph.D. Student, Universidade Federal de Santa Catarina (Santa Catarina, Brazil)

Matthew Tietbohl: Ph.D. Candidate, King Abdullah University of Science and Technology (Thuwal, Saudi Arabia)

Dr. Damian G. Vales: Research Professor, Centro Nacional Patagonico (Puerto Madryn, Argentina)

Katie Wedemeyer-Strombel: Ph.D. Candidate, University of Texas El Paso (El Paso)

Hannah Wellman: Ph.D. Candidate, University of Oregon (Eugene)

Dana Wright: Ph.D. Candidate, Duke University (Beaufort)

Dr. Nico deBruyn: Professor, Pretoria University (Pretoria)

Dr. Stanley Gehrt: Professor, Ohio State University (Columbus)

Dr. Marilyn L. Fogel: Professor and EDGE Director, UC Riverside (Riverside)

Dr. Chris Harrod: Professor, University of Antofagasta (Antofagasta, Chile)

Dr. Keith A. Hobson: Professor, Western Ontario University (London, Canada)

Dr. Tyler Kartzinel: Assistant Professor, Brown University (Providence)

Dr. Douglas Kelt: Professor, University of California Davis (Davis)

Dr. Kate Lyons: Assistant Professor, University of Nebraska (Lincoln)

Dr. Karin Maldonado: Professor, Universidade Adolfo Ibañez (Santiago, Chile)

Dr. Craig McClain: Executive Director, Louisiana Marine Consortium (Chauvin)

Dr. Gabriela Nardoto: Professor, Universidade de Brasilia (Brasilia, Brazil)

Dr. Luciana Riccialdelli: Professor, Centro Austral de Investigaciones Cientificas (Ushuaia, Argentina)

Dr. Andy Read: Professor, Duke University Marine Laboratory (Beaufort)

Dr. Pablo Sabat: Professor, Universidade de Chile (Santiago, Chile)

Dr. Irene Salinas: Associate Professor, University of New Mexico (Albuquerque)

Dr. Zachary Sharp: Distinguished Professor, University of New Mexico (Albuquerque)

Dr. Felisa Smith: Professor, University of New Mexico (Albuquerque)

Dr. Cristina Takacs-Vesbach: Professor, University of New Mexico (Albuquerque)

Dr. Justin Yeakel: Assistant Professor, University of California Merced (Merced)