TY - BOOK AU - Boyd,Robert AU - Silk,Joan B. TI - How humans evolved SN - 039317915x (pbk.) AV - GN 281 .B66 2005 U1 - 599.93/8 21 PY - 2005/// CY - New York PB - W. W. Norton KW - Human evolution N1 - Includes bibliographical references and index ER -