The material in this book came together over more than a decade with the help and input of countless family, friends, and collaborators. First and foremost I thank my wife, Janice, and children, Alex and Clara, for their support and good humor while I was off doing fieldwork, stuck in the lab measuring urine samples, or cloistered in the basement pounding out this book. Thanks, guys. Love you.
I’m likewise grateful to my family (Mom, Dad, George, Heide, Holly, and Emily) for raising me to think critically and enjoy a good argument. Jeff Kurland, Alan Walker, Bob Burkolder, and others at Penn State provided guidance and opportunities during those formative undergrad years that shaped my trajectory as a scientist and ultimately made this book possible.
The Hadza community has been incredibly generous and welcoming to my colleagues and me, graciously welcoming us into their camps and putting up with our endless questions and requests. Stories and conversations in this book from my research with the Hadza (and elsewhere) all come from real experiences, and are rendered as accurately as my memory and occasional journal entries will allow. I thank the Hadza for their hospitality and friendship, and I hope the accounts of their life in this book paint an accurate portrait of their remarkable culture. To learn more about the Hadza community, please visit HadzaFund.org.
None of my work with the Hadza would have been possible without my close friends and collaborators, Brian Wood and David Raichlen. My work in Tanzania over the years has also been facilitated and enriched by a long list of friends, including Mariamu Anyawire, Herieth Cleophas, Jake Harris, Christian Kiffner, Fides Kirei, Lieve Lynen, Nathaniel Makoni, Audax Mabulla, Ibrahim Mabulla, Carla Mallol, Frank Marlowe, Ruth Mathias, Elena Mauriki, Bunga Paolo, Daudi Peterson, and Christopher and Nani Schmelling.
Science is a team sport, and I’ve had the great fortune of learning from and working with many of the best researchers in human evolution and energetics. Stephan Guyenet, Kevin Hall, Daniel Lieberman, and John Speakman have shared critical insights over the years as well as feedback on an early draft of this book. The ideas and material here also benefited from conversations and collaborations with Leslie Aiello, Andrew Biewener, Rick Bribiescas, John Buse, Vincent Careau, Eric Charnov, Steve Churchill, Meg Crofoot, Maureen Devlin, Lara Dugas, Holly Dunsworth, Peter Ellison, Melissa Emery Thompson, Reid Ferring, Michael Gurven, Anthony Hackney, Lewis Halsey, Steve Heymsfield, Kim Hill, Richard Kahn, Hillard Kaplan, William Kraus, Christopher Kuzawa, Mitchell Irwin, Karen Isler, Amy Luke, Paul MacLean, Felicia Madimenos, Andrew Marshall, Ed Melanson, Deborah Muoio, Martin Muller, Guy Plasqui, Susan Racette, Eric Ravussin, Leanne Redman, Jessica Rothman, Stephen Ross, Robert Shumaker, Joshua Snodgrass, Dale Schoeller, Lawrence Sugiyama, Benjamin Trumble, Claudia Valeggia, Carel Van Schaik, Erin Vogel, Kara Walker, Christine Wall, Klaas Westerterp, William Wong, Richard Wrangham, and Yosuke Yamada. I thank the U.S. National Science Foundation, the Wenner-Gren Foundation, and the Leakey Foundation for supporting my research.
I’ve also been fortunate to work closely with a great team of students, postdocs, and research assistants who made much of the research in this book possible and nearly all of it fun. I thank them for their collegiality, clever ideas, and hard work. A full list would be a book unto itself, but I’d be remiss not to mention Caitlin Thurber (who led the Race Across the USA study), Sam Urlacher (who led the Shuar studies featured in this book), Mary Brown, Eric Castillo, Martin Hora, Jörg Jäger, Elaine Kozma, Myra Laird, Cara Ocobock, Jenny Paltan, Rebecca Rimbach, Khalifa Stafford, Zane Swanson, and Anna Warrener.
I’m indebted to Max Brockman, my agent, for his work to find this book a home. I thank Caroline Sutton, my keen-eyed and encouraging editor, along with Hannah Steigmeyer, Dorian Hastings, and the production team at Penguin Random House, for shepherding me through the long process of making this book. Kasia Konopka produced the graphs in this book. Victoria Ehrhardt, Holly Daniels, Emily Khan, Saleem Khan, and Janice Wang read a draft of this book and provided helpful feedback. Finally, I thank the community here at Duke University, particularly Brian Hare and Vanessa Woods, for their friendship and support while I wrote this book.