Samuel S. Urlacher, PhD

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

I am an anthropologist and biologist who uses evolutionary thinking to better understand variation in human biology, aging, and health. I am particularly interested in how children allocate energetic resources (i.e., calories) between competing physiological tasks and how early life experiences and economic development shape lifetime metabolic health (e.g., obesity, inflammation, allergies/asthma, cardiovascular disease, type 2 diabetes). My long-term field and laboratory research is performed with small-scale populations in Ecuador and Papua New Guinea. The Human Evolutionary Biology and Health Lab that I direct at Baylor – housed in the state-of-the-art Anthropology Core Lab – specializes in the measurement of total daily energy expenditure (via doubly labeled water stable isotope analysis), basal metabolism (via indirect calorimetry) and immune/growth biomarkers and hormones (via ELISA and other methods). My projects are theoretically driven. However, I strive to improve the lives of the people that participate in my research and, ultimately, to reduce global health disparities.

My major research questions include:

1) How have humans evolved to spend calories on life’s competing metabolic tasks, including reproduction, growth, physical activity, and immune activity?

2) How do infections and energetic conditions experienced during childhood impact growth, aging, and adult metabolic health?

3) How does economic development (via effects on lifestyle, diet, stress, and pathogen exposure) alter patterns of energy expenditure in ways that lead to obesity and epidemiological transition?

4) How do gut microbes mediate the effects of economic development on metabolism, inflammation, and health?

5) What roles do somatic (e.g., body fat) and social (e.g., alloparenting) capital play in moderating relationships between energy availability/use, experienced stress, and expressed phenotype?

My research is highly collaborative, involving fantastic researchers, students, and local colleagues. I currently collaborate with individuals and institutions from the United States, Ecuador, Papua New Guinea, Mexico, Germany, France, Switzerland, and the Czech Republic. My work has been funded by the National Science Foundation, the LSB Leakey Foundation, the Czech Science Foundation, and others. I prioritize the communication of my research findings to policy makers and to the public. My work has been featured by media outlets such as Good Morning America, El País, The Scientist magazine, Discover magazine, and Muscle and Fitness. I have discussed the implications of my findings at the United Nations headquarters in New York, the ASU Center for Evolution and Medicine, the Senckenberg Naturmuseum in Frankfurt, and elsewhere.

Follow me on Twitter @SSUrlacher

Please contact me with educational and 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 teaching and mentoring students at both the undergraduate and graduate levels. My teaching centers around one theme: How would I like a student to grow by taking my class, hearing my lecture, or being in my lab? The precise answer to this question varies, but the belief that learning must be a transformative experience remains. I challenge myself to help students think about, interpret evidence for, and understand what it means to be human in new and exciting ways. To do this, I incorporate real world examples, active-learning techniques, and new technology to engage students during class and to foster integrative understandings of complex issues. I make a concerted effort to promote the development of different skillsets and modes of communication using assignments in a number of media forms. My students are encouraged to gain new skills and to test their own hypotheses by participating in my ongoing research in the field or in the lab.

Prospective students: All students are welcome in my classroom and in my lab! My policies are designed to provide a safe and welcoming environment for everyone. My research directly addresses topics of human variation and inequality, and I strive to enrich my classroom and lab by fostering an environment of individuals with diverse experiences and backgrounds. Potential PhD students should contact me directly ( The Baylor PhD program in Anthropology is also scheduled to begin in the near future. I am particularly interested in PhD students who would like to focus on topics relating to child energetics, evolutionary medicine, the developmental origins of health and disease, stress and immunity, and the role of the gut microbiome in obesity and the epidemiological transition. Underrepresented students, including native Spanish and Tok Pisin speakers, are highly encouraged to contact me.

Recent Publications

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.