We Are What We Ate: The Diets That Fueled Human Evolution

The vast majority of human evolutionary history was fueled by diets composed exclusively of wild foods gathered and hunted rather than planted and raised. Compared to our ape-ancestors, and in contrast to today's living apes, members of the genus Homo have increasingly relied on technology and cumulative culture, such as use of complex tools, fire, and later fermentation, to access a broader range of foods across diverse ecosystems while defining foodways and regional identities. These innovations facilitated the global radiation of humans to every corner of the planet. Following the Last Glacial Maximum, approximately 12,000 years ago, the transition to agriculture marked a pivotal shift in human dietary patterns. The domestication of crops and livestock enabled food surplus, sedentism, and population growth, while introducing new nutritional and health consequences. More recently, widespread industrial food processing and ultra-refined diets may be driving additional physiological changes with unknown consequences for metabolism, disease, and the human microbiome, along with environmental impacts. This symposium examines the diets that fueled human evolution, drawing on evidence from paleontology, archeology, genetics, comparative anatomy and physiology, modern nutritional science, microbiome research, and ethnographic studies of the few remaining living foragers. Together, these perspectives can illuminate how dietary adaptations have shaped and continue to influence human biology, health, and culture.

Event Sessions:

Speakers	Session
Matthew Sponheimer	The diets of early hominins
Jessica Thompson	The hominin predatory pattern
Nathaniel Dominy	Plant/starch consumption in human evolution
Ajit Varki	The role of red meat: From a blessing to a curse
Rachel Carmody	The importance of cooked food
Justin Sonnenburg Erica Sonnenburg	The microbiome
Erin Hecht	Fermentation and human brain expansion The expansion of the human brain represents a metabolic paradox: how did our ancestors fuel such an energetically expensive organ while reducing the size of the digestive tract? While the "Cooking Hypothesis" suggests fire was the primary driver, the transition likely began much earlier. This talk will explore the External Fermentation Hypothesis, proposing that the intentional or accidental fermentation of foods could have provided a crucial "external stomach." By outsourcing the work of... read more
Stefan Ruhl	Human evolution, spit by spit
Lora Iannotti	The diets of children past and present
All Speakers Erica Sonnenburg Pascal Gagneux	Wrap-up, Question & Answer Session, and Closing Remarks Question and answer session with all speakers. Wrap-Up by symposium co-chair, Erica Sonnenburg. Closing remarks by CARTA Executive Co-Director, Pascal Gagneux.