Scientific American - Ecology & Evolutionary Biology - University of ...
Scientific American - Ecology & Evolutionary Biology - University of ... Scientific American - Ecology & Evolutionary Biology - University of ...
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Established 1845 ® Becoming Human is published by the staff of Scientifi c American, with project management by: EDITOR IN CHIEF: John Rennie EXECUTIVE EDITOR: Mariette DiChristina ISSUE EDITOR: Dawn Stover ISSUE CONSULTANT: Kate Wong ART DIRECTOR: Edward Bell ISSUE DESIGNER: Lucy Reading-Ikkanda PHOTOGRAPHY EDITORS: Emily Harrison, Smitha Alampur PRODUCTION EDITOR: Richard Hunt COPY DIRECTOR: Maria-Christina Keller COPY CHIEF: Molly K. Frances ASSISTANT COPY CHIEF: Daniel C. Schlenoff COPY AND RESEARCH: Michael Battaglia, Sara Beardsley EDITORIAL ADMINISTRATOR: Jacob Lasky SENIOR SECRETARY: Maya Harty ASSOCIATE PUBLISHER, PRODUCTION: William Sherman MANUFACTURING MANAGER: Janet Cermak ADVERTISING PRODUCTION MANAGER: Carl Cherebin PREPRESS AND QUALITY MANAGER: Silvia De Santis PRODUCTION MANAGER: Christina Hippeli CUSTOM PUBLISHING MANAGER: Madelyn Keyes-Milch ASSOCIATE PUBLISHER/VICE PRESIDENT, CIRCULATION: Lorraine Leib Terlecki CIRCULATION DIRECTOR: Simon Aronin RENEWALS MANAGER: Karen Singer FULFILLMENT AND DISTRIBUTION MANAGER: Rosa Davis VICE PRESIDENT AND PUBLISHER: Bruce Brandfon WESTERN SALES MANAGER: Debra Silver SALES DEVELOPMENT MANAGER: David Tirpack SALES REPRESENTATIVES: Jeffrey Crennan, Stephen Dudley, Stan Schmidt ASSOCIATE PUBLISHER, STRATEGIC PLANNING: Laura Salant PROMOTION MANAGER: Diane Schube RESEARCH MANAGER: Aida Dadurian PROMOTION DESIGN MANAGER: Nancy Mongelli GENERAL MANAGER: Michael Florek BUSINESS MANAGER: Marie Maher MANAGER, ADVERTISING ACCOUNTING AND COORDINATION: Constance Holmes DIRECTOR, SPECIAL PROJECTS: Barth David Schwartz MANAGING DIRECTOR, ONLINE: Mina C. Lux OPERATIONS MANAGER, ONLINE: Vincent Ma SALES REPRESENTATIVE, ONLINE: Gary Bronson MARKETING DIRECTOR, ONLINE: Han Ko DIRECTOR, ANCILLARY PRODUCTS: Diane McGarvey PERMISSIONS MANAGER: Linda Hertz MANAGER OF CUSTOM PUBLISHING: Jeremy A. Abbate CHAIRMAN EMERITUS: John J. Hanley CHAIRMAN: John Sargent PRESIDENT AND CHIEF EXECUTIVE OFFICER: Gretchen G. Teichgraeber VICE PRESIDENT AND MANAGING DIRECTOR, INTERNATIONAL: Dean Sanderson VICE PRESIDENT: Frances Newburg PHIL SAUNDERS Space Channel Ltd. letter from the editor An Unlikely Ascendancy a savvy handicapper would never have put money on the continued existence of this evolutionary dark horse. Nearly hairless, weak— no sharp claws or slicing teeth here— and slow, with a bumpy bipedal gait, humans might initially appear to be one of the unlikeliest survivors on earth. Except for the oversize brains. As the articles in this special edition collectively underscore, so much of the rise of our ancestors from humble beginnings to today’s worlddominant swell of humanity tracked the stunning growth of all that furrowed cortex. From roughly two million years to 250,000 years ago, the brain’s total volume expanded by a tablespoonful every 100,000 years, estimates Harvard University biologist E. O. Wilson. If we could stretch a modern person’s cortex fl at, it would occupy an area the size of four sheets of standard letter-size paper. In contrast, a chimp’s would cover one sheet; a monkey’s, a postcard; and a rat’s, a stamp. But size alone does not explain our matchless reasoning skills. One of the mysteries of human evolution is that other species with large brains (such as Neandertals) seemingly did not achieve comparable levels of cognition. Could a cultural innovation, perhaps driven by rapid environmental changes, have contributed to the rise of symbolic thought, language and cooperative group society? Ian Tattersall speculates along these lines in “How We Came to Be Human,” starting on page 66, and William H. Calvin explores “The Emergence of Intelligence,” beginning on page 84. As our primate ancestors’ intellects deepened, their bodies continued to morph. Their need to stoke the energy-consuming organ in their skulls with nutritious, calorie-rich fuel created selection pressure favoring features now characteristic of primates, such as grasping hands with opposable thumbs, relates Katharine Milton in “Diet and Primate Evolution,” starting on page 22. “To a great extent,” concludes Milton, “we are truly what we eat.” Other articles in the issue explore how and when early humans and our ape cousins began to sprawl around the planet. Even as recent discoveries answer some questions about our fascinating and complex history, they raise others. Alone among creatures alive today, we enjoy the ability to contemplate our species’ odyssey through time. Food for thought. Mariette DiChristina Executive Editor Scientifi c American editors@sciam.com www.sciam.com SCIENTIFIC AMERICAN 1 COPYRIGHT 2006 SCIENTIFIC AMERICAN, INC.
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- Page 7 and 8: Apes BY DAVID R. BEGUN Fossil ape r
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- Page 19 and 20: LAURIE GRACE mony, I labeled them r
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