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 competence and with regard for appropriate balance.
The report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine.
This study by the National Research Council's Commission on Life Sciences was sponsored by Environmental Protection Agency contract 68-C1-0025, National Science Foundation contract BSR-9109994, Department of Agriculture contract 59-0700-2-154, Department of the Interior contract 4-01-0001-91-C-25, Department of Energy contract DE-FG05-91ER61172, and the National Oceanic and Atmospheric Administration.
Library of Congress Catalog Card No. 93–84438
International Standard Book No. 0-309-04929-6
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Copyright 1993 by the National Academy of Sciences. All rights reserved.
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First Printing, July 1993
Second Printing, April 1994