UNDERSTANDING CLIMATE’S INFLUENCE ON HUMAN EVOLUTION
THE NATIONAL ACADEMIES PRESS
Washington, D.C.
www.nap.edu
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NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.
The opinions, findings, and conclusions or recommendations contained in this document are those of the authors and do not necessarily reflect the views of the National Science Foundation. Mention of trade names or commercial products does not constitute their endorsement by the U.S. government. Supported by the National Science Foundation under Award No. EAR-0625247.
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Cover: Cover design by Francesca Moghari. Front Cover: Five fossil human skulls show how the shape of the face and braincase of early humans changed over the past 2.5 million years (from left to right: Australopithecus africanus, 2.5 million years old; Homo rudolfensis, 1.9 million years old; Homo erectus, ~1 million years old; Homo heidelbergensis, ~350,000 years old; Homo sapiens, ~4,800 years old). The images are courtesy of the Human Origins Program of the Smithsonian Institution and photo credits include Chip Clark, Jim DiLoreto, and Don Hurlbert, all of the Smithsonian Institution. The bottom image is a composite image with an oxygen isotope record from and courtesy of James Zachos. The cracked mud image is courtesy of Free Nature Pictures. The woodland image is courtesy of Kaye Reed, National Science Foundation. Back Cover: The drill rig is courtesy of Jason Agnich, University of Minnesota-Duluth. The wetland, savannah, and ground examination images are also courtesy of Kaye Reed.
Copyright 2010 by the National Academy of Sciences. All rights reserved.
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THE NATIONAL ACADEMIES
Advisers to the Nation on Science, Engineering, and Medicine
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COMMITTEE ON THE EARTH SYSTEM CONTEXT FOR HOMININ EVOLUTION
ROBERT M. HAMILTON (Chair) Independent Consultant,
Zelienople, Pennsylvania
BERHANE ASFAW,
Rift Valley Research Service, Addis Ababa, Ethiopia
GAIL M. ASHLEY,
Rutgers University, Piscataway, New Jersey
THURE E. CERLING,
University of Utah, Salt Lake City
ANDREW S. COHEN,
University of Arizona, Tucson
PETER B. DEMENOCAL,
Lamont-Doherty Earth Observatory, Palisades, New York
ANDREW P. HILL,
Yale University, New Haven, Connecticut
THOMAS C. JOHNSON,
University of Minnesota, Duluth
JOHN E. KUTZBACH,
University of Wisconsin, Madison
RICHARD POTTS,
National Museum of Natural History, Smithsonian Institution, Washington, D.C.
KAYE E. REED,
Arizona State University, Tempe (resigned May 2009)
ALAN R. ROGERS,
University of Utah, Salt Lake City
ALAN C. WALKER,
The Pennsylvania State University, University Park
National Research Council Staff
DAVID A. FEARY, Study Director
NICHOLAS D. ROGERS, Research Associate
JENNIFER T. ESTEP, Financial and Administrative Associate
TONYA E. FONG YEE, Senior Program Assistant
BOARD ON EARTH SCIENCES AND RESOURCES
CORALE L. BRIERLEY (Chair),
Brierley Consultancy, LLC, Highlands Ranch, Colorado
KEITH C. CLARKE,
University of California, Santa Barbara
DAVID J. COWEN,
University of South Carolina, Columbia
WILLIAM E. DIETRICH,
University of California, Berkeley
ROGER M. DOWNS,
The Pennsylvania State University, University Park
JEFF DOZIER,
University of California, Santa Barbara
KATHERINE H. FREEMAN,
The Pennsylvania State University, University Park
WILLIAM L. GRAF,
University of South Carolina, Columbia
RUSSELL J. HEMLEY,
Carnegie Institution of Washington, Washington, D.C.
MURRAY W. HITZMAN,
Colorado School of Mines, Golden
EDWARD KAVAZANJIAN, JR.,
Arizona State University, Tempe
LOUISE H. KELLOGG,
University of California, Davis
ROBERT B. MCMASTER,
University of Minnesota, Minneapolis
CLAUDIA INÉS MORA,
Los Alamos National Laboratory, New Mexico
BRIJ M. MOUDGIL,
University of Florida, Gainesville
CLAYTON R. NICHOLS,
Department of Energy, Idaho Operations Office (Retired), Ocean Park, Washington
JOAQUIN RUIZ,
University of Arizona, Tucson
PETER M. SHEARER,
University of California, San Diego
REGINAL SPILLER,
Allied Energy, Houston, Texas
RUSSELL E. STANDS-OVER-BULL,
Anadarko Petroleum Corporation, Denver, Colorado
TERRY C. WALLACE, JR.,
Los Alamos National Laboratory, New Mexico
HERMAN B. ZIMMERMAN,
National Science Foundation (Retired), Portland, Oregon
National Research Council Staff
ANTHONY R. DE SOUZA, Director
ELIZABETH A. EIDE, Senior Program Officer
DAVID A. FEARY, Senior Program Officer
ANNE M. LINN, Senior Program Officer
SAMMANTHA L. MAGSINO, Program Officer
MARK D. LANGE, Associate Program Officer
LEA A. SHANLEY, Postdoctoral Fellow
JENNIFER T. ESTEP, Financial and Administrative Associate
NICHOLAS D. ROGERS, Financial and Research Associate
COURTNEY R. GIBBS, Program Associate
JASON R. ORTEGO, Research Associate
ERIC J. EDKIN, Senior Program Assistant
TONYA E. FONG YEE, Senior Program Assistant
Preface
Understanding the origins of humanity has long been one of our foremost intellectual pursuits, and one that greatly interests the general public as evidenced by museum attendance and by numerous media productions and general interest publications. Progress toward an improved understanding of our heritage is a continuing challenge for the scientific community, requiring advances in a range of disciplines that include archaeology, anthropology, geology, biology, oceanography, and genetics, and particularly research advances in areas where two or more of these fields intersect. One of the key questions in this interdisciplinary quest is how the environment, and specifically climate, shaped the evolution of our species and that of our close relatives.
Some of the most critical world issues today also bear on human evolution, in the sense that how we got here is relevant to where we are going as a species. For example, global warming, population growth with its attendant demands on limited resources, pandemic threats of virulent diseases, and availability of weapons that can cause massive damage and render parts of the globe uninhabitable, all demand more rational policy decisions that take into account the long evolutionary process that brought humanity to world dominance. Perhaps a greater appreciation of what the people of the world have in common, rather than their differences, might encourage more cooperation.
Although recent advances in knowledge of human evolution have been substantial, they really have only laid the groundwork for future achievements. New methodologies for establishing the ages of specimens and analyzing them with sophisticated instrumentation, and for acquiring information about past environments through drilling on land and in lakes and the ocean, set the stage for further discoveries. Accelerated research not only offers potential for highly significant
advances, there is also an urgency in moving ahead due not only to the global and regional threats mentioned above, but also to the loss of potential specimen sites as a result of development and even vandalism.
Although research activity at the intersection of different scientific disciplines is inherently difficult, such research carries with it great potential for advances that can transform understanding. Although the usual issues of differing perspectives and different jargon were encountered during this study, the challenges of providing recommendations for new approaches that would guide research activity over the next decade or more provided the incentive to bridge the divisions. Our deliberations were particularly helped by the open community workshop hosted by the committee, with its focus on receiving a broad range of input from many experts whose disciplinary fields impinged upon the broad scope of the committee’s charge. This input, and the presentations by other experts at committee meetings, provided a solid base for informing the committee’s deliberations and recommendations.
Robert M. Hamilton
Chair
Acknowledgments
This report was greatly enhanced by those who made presentations to the committee at the public committee meetings and by the participants at the open workshop sponsored by the committee to gain community input—Leslie Aiello, Ray Bernor, René Bobe, Erik Brown, Frank Brown, Tony de Souza, Larry Edwards, Sarah Feakins, Mikael Fortelius, Don Grayson, Tim Herbert, Tim Jull, Rich Kay, Dennis Kent, Chris Kuzawa, Rich Lane, Peter Molnar, Curtis Marean, Kathleen Nicoll, Dolores Piperno, Todd Preuss, Christina Ravelo, Bill Ruddiman, Jim Russell, Jeff Schuffert, Eugenie Scott, Steven Stanley, Peter Ungar, Xiaoming Wang, Ken Weiss, Mark Weiss, Tim White, and John Yellen. The presentations and discussions at these meetings provided invaluable input and context for the committee’s deliberations.
This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the NRC’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their participation in the review of this report:
René Bobe, Department of Anthropology, University of Georgia, Athens
John G. Fleagle, Department of Anatomical Sciences, State University of New York, Stony Brook
Terry Harrison, Department of Anthropology, New York University
Jeffrey T. Kiehl, National Center for Atmospheric Research, Boulder, Colorado
Richard G. Klein, Department of Anthropology and Department of Biology, Stanford University, California
Mark A. Maslin, Department of Geography, University College London, United Kingdom
David Pilbeam, Department of Human Evolutionary Biology and Peabody Museum, Harvard University, Cambridge, Massachusetts
Anne C. Stone, School of Human Evolution and Social Change, Arizona State University, Tempe
Bernard A. Wood, Department of Anthropology, George Washington University, Washington, D.C.
Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations nor did they see the final draft of the report before its release. The review of this report was overseen by P. Geoffrey Feiss, College of William and Mary, Williamsburg, Virginia, appointed by the Divison on Earth and Life Studies, who was responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution.