Samuel S. Urlacher, PhD

Samuel S. Urlacher, PhD
Assistant Professor
High Res Photo
Research in Progress

I am an anthropologist and human evolutionary biologist with an integrative biocultural research program. My lab's primary aim is to define the evolved energetic pathways that drive variation in human development, metabolism, and health. To do so, we address a range of research questions that span the traditional disciplines of human biology, behavioral ecology, evolutionary medicine, and global health. Our research questions include:

1. How have humans evolved to spend calories on life’s competing metabolic tasks (e.g., immune activity, brain development, growth, reproduction) across the life course?

2. Why are disadvantaged children and those experiencing rapid lifestyle change at risk for the “dual burden” of growth faltering and later life obesity?

3. How do chronic stress and altered gut microbiomes impact child development and lifetime metabolism/health?

4. Why did childhood and the unique human life history pattern evolve?

The Human Evolutionary Biology and Health Lab that I direct at Baylor specializes in the measurement of human energy expenditure (via doubly labeled water stable isotope tracking) and physiological biomarkers and hormones. My long-term field research is performed collaboratively with Indigenous populations in Ecuador and Papua New Guinea. I am also engaged in other domestic and international projects. This work addresses fundamental topics in anthropology and biology, but it also strives to reduce health disparities and to improve the lives of the amazing people that participate in my research.

My research has been funded by the National Science Foundation, the Leakey Foundation, CIFAR, the Jacobs Foundation, the Czech Science Foundation, and others. Science communication is important to me. My work has been featured by various outlets, including The New York Times, Good Morning America, Healthline, El País, The Chicago Tribune, and The Scientist magazine. I am currently a CIFAR Azrieli Global Scholar in the Child and Brain Development Program.

Please contact me with education and public outreach opportunities!


PhD in Human Evolutionary Biology, Harvard University, 2016

MA in Human Evolutionary Biology, Harvard University, 2012

BS in Human Biology and Anthropology, Brown University, 2009


Teaching is closely integrated with my role as a researcher, and I am committed to mentoring students at both the undergraduate and graduate levels. I strive to provide my students with a transformative learning experience. I challenge them to think about, interpret evidence for, and understand what it means to be human in new and exciting ways. I apply active-learning techniques and new technology to engage students and to foster integrative understanding of complex issues. I make a concerted effort to promote the development of different skillsets and modes of communication using assignments in several media forms. Importantly, my students are encouraged to gain new skills and to test their own hypotheses by actively participating in research in the field or in the lab.

Prospective students: Graduate and undergraduate students are essential members of my lab. All are welcome – our lab policies are designed to provide an environment for everyone to do good science and to thrive intellectually (and to have fun while doing it, of course). Interested students should visit the HEBHL website and email me directly (, including a CV/resume. PhD applicants should consider both the Anthropology PhD and Biology PhD programs at Baylor. I am particularly interested in PhD applicants who would like to focus on evolutionary energetics projects involving children’s nutrition/epidemiological transition, human aging and life history evolution, the role of inflammation/stress in the developmental origins of health disparities, and the dual burden of growth stunting and later life obesity. Those with field, lab, and/or computational modeling experience are especially encouraged to apply.

Recent Publications

Pontzer H and the IAEA DLW Database Team (incl. Urlacher SS). 2021. Daily energy expenditure through the human life course. Science 373:808-812. DOI: 10.1126/science.abe5017.

Careau V and the IAEA DLW Database Team (incl. Urlacher SS). 2021. Energy compensation and adiposity in humans. Current Biology 31:1-8. DOI: 10.1016/j.cub.2021.08.016.

Urlacher SS, Snodgrass JJ, Dugas LR, Madimenos FC, Sugiyama LS, Liebert MA, Joyce CJ, Terán E, Pontzer H. 2021. Childhood daily energy expenditure does not decrease with market integration and is not related to adiposity in Amazonia. The Journal of Nutrition 195(3):695-704. DOI:

Cepon-Robins TA, Blackwell AD, Gildner TE, Liebert MA, Urlacher SS, Madimenos FC, Eick GN, Snodgrass JJ, Sugiyama LS. 2021. Pathogen disgust sensitivity protects against infection in a high pathogen environment. Proceedings of the National Academy of Sciences 118(8):e2018552118. DOI: 10.1073/pnas.2018552118.

DeLouize AM, Liebert MA, Madimenos FC, Urlacher SS, Schrock JM, Cepon-Robins TJ, Gildner TE, Blackwell AD, Harrington CJ, Amir D, Bribiescas RG, Snodgrass JJ, Sugiyama LS. 2021. Low prevalence of anemia among Shuar communities of Amazonian Ecuador. American Journal of Human Biology 2021:e23590. DOI: 10.1002/ajhb.23590.

Pontzer H, Brown MH, Wood BM, Raichlen DA, Mabulla AZP, Harris JA, Dunsworth H, Hare B, Walker K, Luke A, Dugas LR, Schoeller D, Plange-Rhule J, Shumaker PRW, Rothman JM, Vogel E, Sulistyo F, Alavi S, Prasetyo D, Urlacher SS, Ross SR. 2021. Evolution of Water Conservation in Humans. Current Biology 31:1-7. DOI:

Speakman J and the IAEA DLW Database Team (incl. Urlacher SS). 2021. A standard calculation methodology for human doubly labeled water studies. Cell Reports Medicine 2:100203. DOI: 10.1016/j.xcrm.2021.100203. 

Gildner TE, Cepon-Robins TJ, Liebert MA, Urlacher SS, Schrock JM, Harrington CJ, Madimenos FC, Snodgrass JJ, Sugiyama LS. 2020. Market integration and soil-transmitted helminth infection among the Shuar of Amazonian Ecuador. PLoS ONE 15(7):e0236924. DOI: 10.1371/journal.pone.0236924. 

Madimenos FC, Liebert MA, Cepon-Robins TJ, Urlacher SS, Snodgrass JJ, Sugiyama LS, Stieglitz J. 2020. Disparities in bone density across contemporary Amazonian forager-horticulturalists: Cross population comparison of the Tsimane and Shuar. American Journal of Physical Anthropology 171(1):50-64.

Urlacher SS, Snodgrass JJ, Dugas LR, Sugiyama LS, Liebert MA, Joyce CJ, Pontzer H. 2019. Constraint and tradeoffs regulate energy expenditure during childhood. Science Advances 5(12):eaax1065.

Cepon-Robins TJ, Gildner TE, Schrock J, Eick G, Liebert MA, Urlacher SS, Madimenos FC, Harrington CJ, Amir D, Bribiescas RG, Sugiyama LS, Snodgrass JJ. 2019. Soil-transmitted helminth infection and intestinal inflammation among the Shuar of Amazonian Ecuador. American Journal of Physical Anthropology 170(1):65-74.

Christopher L, Madimenos FC, Bribiescas RG, Urlacher SS, Snodgrass JJ, Sugiyama LS, Pontzer H. 2019. High energy requirements and water throughput of adult Shuar forager horticulturalists of Amazonian Ecuador. American Journal of Human Biology 31:e23223.

Urlacher SS, Ellison PT, Sugiyama LS, Pontzer H, Eick G, Liebert MA, Cepon-Robins TJ, Gildner TE, Snodgrass JJ. 2018. Tradeoffs between immune function and childhood growth among Amazonian forager-horticulturalists. Proceedings of the National Academy of Sciences 115(17):e3914-3921.

Urlacher SS & Kramer KL. 2018. Evidence for energetic tradeoffs between physical activity and childhood growth across the nutritional transition. Scientific Reports 8(369):1-10.

Urlacher SS, Liebert MA, and Konečná M. 2018. Global variation in diurnal cortisol rhythms: Evidence from Garisakang forager-horticulturalists of lowland Papua New Guinea. Stress 21(2):101-109.

Slopen N, Zhang J, Urlacher SS, DeSilva G, Mittal M. 2018. Maternal experiences of intimate partner violence and C-reactive protein levels in young children in Tanzania. Social Science & Medicine – Population Health 6(2018):107-115.

Stagaman K, Cepon-Robins TJ, Liebert MA, Gildner TE, Urlacher SS, Madimenos FC, Guillemin K, Snodgrass JJ, Sugiyama LS, Bohannan BJM. 2018. Market Integration Predicts Human Gut Microbiome Attributes across a Gradient of Economic Development. mSystems 3(1):1-10.

Konečná M & Urlacher SS. 2017. Male social status and its predictors among Garisakang forager-horticulturalists of lowland Papua New Guinea. Evolution and Human Behavior 38(6):789-797.

Blackwell AD, Urlacher SS, Boheim B, von Rueden C, Jaeggi A, Stieglitz J, Trumble BC, Gurven M, Kaplan H. 2017. Growth references for Tsimane forager-horticulturalists of the Bolivian Amazon. American Journal of Physical Anthropology 162(3):441-461.

Urlacher SS, Liebert MA, Snodgrass JJ, Blackwell AB, Cepon-Robins TJ, Gildner TE, Madimenos, FC, Amir D, Bribiescas RG, Sugiyama LS. 2016. Heterogeneous effects of market integration on sub-adult body size and nutritional status among the Shuar of Amazonian Ecuador. Annals of Human Biology 43(4):316-329.

Urlacher SS, Snodgrass JJ, Cepon-Robins TJ, Liebert MA, Gildner TE, Sugiyama LS. 2016. The application of knemometry to measure childhood short-term growth among the indigenous Shuar of Ecuador. American Journal of Physical Anthropology 160(2):353-357.

Urlacher SS, Blackwell AD, Liebert MA, Madimenos FC, Snodgrass JJ, Sugiyama LS. 2016. Physical growth of the Shuar: Height, weight, and BMI references for an indigenous Amazonian population. American Journal of Human Biology 28(1):16-30.

Eick G, Urlacher SS, McDade TW, Snodgrass JJ. 2016. Validation of an optimized ELISA for quantitative assessment of Epstein-Barr virus antibodies from dried blood spots. Biodemography and Social Biology 62(2):222-233.

Gildner TE, Cepon-Robins TJ, Liebert MA, Urlacher SS, Madimenos FC, Snodgrass JJ, Sugiyma LS. 2016. Regional variation in Ascaris lumbricoides and Trichuris trichiura infections by age cohort and sex: effects of market integration among the indigenous Shuar of Amazonian Ecuador. Journal of Physiological Anthropology 35(28):1-11.