www.diako.ir ON THE COVER To celebrate this special issue on food, the cover of this month’s Scientifi c American comes in three fl avorful variations on a culinary theme. Photographs by Dan Saelinger. Prop styling by Dominique Baynes. September 2013 Volume 309, Number 3 the food issue INTRODUCTION 34 On the mysteries of food, including: What makes it taste so darn good? By Michael Moyer feast fuel farm CELEBRATING OUR HOW FOOD THE FUTURE OF THE LOVE OF FOOD CHANGES US FOOD SUPPLY ECOLOGY NUTRITION CONSERVATION 40 How (and Why) to Eat 56 Everything You Know 70 Return of the Natives Invasive Species about Calories Is Wrong If honeybees collapse, so will To tame the world’s gnarliest The count on the label on that a big swath of our food supply. pests, feed them to the world’s bag of almonds can di er wild- Maybe it’s time to enlist other greatest predator. By Bun Lai ly from what your body actually types of bees. By Hillary Rosner NEUROSCIENCE extracts. By Rob Dunn MICROBIOLOGY 44 The Food Addiction PHYSIOLOGY 76 Super Dirt What brain research reveals 60 Which One Will Soil microbes could o er about the obesity epidemic. Make You Fat? an alternative to heavy use By Paul J. Kenny Does an excess of calories cause of fertilizers and pesticides. INNOVATION obesity, or do carbohydrates? By Richard Conni Rigorous studies may soon fi nd 50 The Amazing BIOTECHNOLOGY Multimillion-Year out at last. By Gary Taubes 80 Are Engineered History of ANTHROPOLOGY Foods Evil? Processed Food 66 The First Cookout GMOs are essential to feeding It’s not all Spam and Tang. Anthropologist Richard Wrang- the world, proponents say. Humanity wouldn’t be here ham has new support for the Tampering with nature is peril- without the technologies of notion that cooking made us ous, critics say. Who is right? the kitchen. By Evelyn Kim human. Interview by Kate Wong By David H. Freedman Photograph by Grant Cornett September 2013, Scientifi cAmerican.com 1 www.diako.ir sad0913Toc3p.indd 1 7/29/13 9:04 AM DEPARTMENTS 4 From the Editor 6 Letters 10 Science Agenda Mandatory labeling of genetically modifi ed food is a bad idea. By the Editors 12 Forum Reviving mammoths and other extinct creatures makes sense. By George Church 14 Advances Vultures on extinction’s edge. Crowdsourced sleep science. 3-D-printed body parts. Overprotecting Mars. 28 The Science of Health Lingering lead can be toxic to adults as well as children. By Ingfei Chen 32 TechnoFiles Do gadgets have to become obsolete a week after you bring them home? By David Pogue 90 Recommended The marvelous gira e. Our best hope for Earth. The notorious Milgram experiments. By Lee Billings 92 Skeptic Why great scientists make great mistakes. By Michael Shermer 93 Anti Gravity The reign of incompetent criminals. By Steve Mirsky 94 50, 100 & 150 Years Ago 96 Graphic Science The 5,000-mile salad. By Mark Fischetti ON THE WEB What to Eat? If your appetite for food science is stimulated by this special issue, explore more resources—on everything from fad diets to GMOs to misleadingly labeled foodstu s—to help navigate the sea of confusing information. Go to www.Scientifi cAmerican.com/sep2013/food-resources Scientifi c American (ISSN 0036-8733), Volume 309, Number 3, September 2013, published monthly by Scientifi c American, a division of Nature America, Inc., 75 Varick Street, 9th Floor, New York, N.Y. 10013-1917. Periodicals postage paid at New York, N.Y., and at additional mailing offi ces. Canada Post International Publications Mail (Canadian Distribution) Sales Agreement No. 40012504. Canadian BN No. 127387652RT; TVQ1218059275 TQ0001. Publication Mail Agreement #40012504. Return undeliverable mail to Scientifi c American, P.O. Box 819, Stn Main, Markham, ON L3P 8A2. Individual Subscription rates: 1 year $39.97 (USD), Canada $49.97 (USD), International $61 (USD). Institutional Subscription rates: Schools and Public Libraries: 1 year $72 (USD), Canada $77 (USD), International $84 (USD). Businesses and Colleges/Universities: 1 year $330 (USD), Canada $335 (USD), International $342 (USD). Postmaster: Send address changes to Scientifi c American, Box 3187, Harlan, Iowa 51537. Reprints available: write Reprint Department, Scientifi c American, 75 Varick Street, 9th Floor, New York, N.Y. 10013-1917; fax: 646-563-7138; [email protected]. Subscription inquiries: U.S. and Canada (800) 333-1199; other (515) 248-7684. Send e-mail to scacustserv@cdsfulfi llment.com. Printed in U.S.A. Copyright © 2013 by Scientifi c American, a division of Nature America, Inc. All rights reserved. 2 Scientifi c American, September 2013 www.diako.ir sad0913Toc2p.indd 2 7/24/13 6:35 PM From the Editor Mariette DiChristina is editor in chief of Scientific American. Follow her on Twitter @mdichristina A Scientific Feast er Gary Taubes discusses, be- story, “How (and Why) to Eat ginning on page 60, in “Which Invasive Species,” on page 40. One Will Make You Fat?” It As one editor put it, the even helped make us human; issue ultimately is about how turn to page 66 for senior edi- we play with our food and tor Kate Wong’s interview with how food, in turn, plays with Richard Wrangham of Harvard us. We invite you to dig in. University, “The First Cookout.” On the other hand, we in- SCIENCE IN ACTION tensively manage our sources of sustenance, shaping them Congrats, to our needs and desires and Elif Bilgin affecting the environment on a We have announced erhaps the most months ago, we all became in- global scale. “Are Engineered the 2013 winner of the in timate relation- trigued by the intricate recip- Foods Evil?” David H. Freed- $50,000 Science in Action ship each of us rocal interactions between us man asks regarding our mod- prize, sponsored by will ever have is and our chow. On the one ern breeding techniques, be- S cientific American as part not with any fel- hand, we certainly are what we ginning on page 80. On page of the Google Science Fair, Plow member of our own human eat. Food constitutes our very 50, culinary expert Evelyn Kim the annual global compe- species. Instead—as you have being. It can serve up sensory traces “The Amazing Multimil- tition for students ages no doubt already guessed from delights, as senior editor Mi- lion-Year History of Processed 13 to 18: Elif Bilgin, age 16, the subject and title of this chael Moyer, who organized Food” that has led to the pres- hails from Istanbul, Turkey. special issue—it is between our this single-topic issue, explains ent-day nutritional outputs of See “Turning Peels into bodies and our food. in his essay on the nature of de- the food-industrial complex. Plastic” [Advances], on In fact, when our editorial liciousness, starting on page What we ingest can even work page 19, to learn about her team first discussed pursuing 34. It affects our long-term as an ecosystem corrective, as remarkable work. —M.D. this edition’s theme several health, as nutrition research- chef Bun Lai points out in his BOARD OF ADVISERS Leslie C. Aiello Harold “Skip” Garner Morten L. Kringelbach Carolyn Porco Michael Shermer President, Wenner-Gren Foundation Director, Medical Informatics and Director, Hedonia: TrygFonden Leader, Cassini Imaging Science Publisher, Skeptic magazine for Anthropological Research Systems Division, and Professor, Virginia Research Group, University of Oxford Team, and Director, CICLOPS, Bioinformatics Institute, Virginia Tech and University of Aarhus Michael Snyder Roger Bingham Space Science Institute Professor of Genetics, Stanford Michael S. Gazzaniga Steven Kyle University School of Medicine Co-Founder and Director, Vilayanur S. Ramachandran The Science Network Director, Sage Center for the Study of Mind, Professor of Applied Economics and University of California, Santa Barbara Management, Cornell University Director, Center for Brain and Cognition, Michael E. Webber G. Steven Burrill University of California, San Diego Co-director, Clean Energy Incubator, David J. Gross Robert S. Langer and Associate Professor, CEO, Burrill & Company Professor of Physics and Permanent David H. Koch Institute Professor, Lisa Randall Department of Mechanical Engineering, Arthur Caplan Member, Kavli Institute for Theoretical Department of Chemical Professor of Physics, Harvard University University of Texas at Austin Director, Division of Medical Ethics, Physics,University of California, Santa Engineering, M.I.T. Martin Rees Steven Weinberg Department of Population Health, Barbara (Nobel Prize in Physics, 2004) Lawrence Lessig Astronomer Royal and Professor Director, Theory Research Group, NYU Langone Medical Center Lene Vestergaard Hau Professor, Harvard Law School Department of Physics, of Cosmology and Astrophysics, George M. Church Mallinckrodt Professor of University of Texas at Austin Physics and of Applied Physics, John P. Moore Institute of Astronomy, University (Nobel Prize in Physics, 1979) Director, Center for Computational Professor of Microbiology and Harvard University of Cambridge Genetics, Harvard Medical School Immunology, Weill Medical George M. Whitesides Danny Hillis College of Cornell University John Reganold Professor of Chemistry and Rita Colwell Co-chairman, Applied Minds, LLC Regents Professor of Soil Science Chemical Biology, Harvard University M. Granger Morgan Distinguished University Professor, and Agroecology, Washington University of Maryland College Park Daniel M. Kammen Professor and Head of Nathan Wolfe State University and Johns Hopkins Bloomberg School Class of 1935 Distinguished Professor Engineering and Public Policy, Director, Global Viral Forecasting Initiative of Public Health of Energy, Energy and Resources Group, Carnegie Mellon University Jeffrey D. Sachs and Director, Renewable and Appropriate R. James Woolsey Miguel Nicolelis Director, The Earth Institute, Chairman, Foundation for the Defense Drew Endy Energy Laboratory, University Co-director, Center for of Democracies, and Venture Partner, Professor of Bioengineering, of California, Berkeley Columbia University Neuroengineering, Duke University Lux Capital Management Stanford University Vinod Khosla Eugenie Scott Partner, Khosla Ventures Martin A.