TY - BOOK AU - Boyd,Robert AU - Silk,Joan B. TI - How humans evolved SN - 0393974774 (pbk.) AV - GN281 .B66 2000 U1 - 599.93/8 21 PY - 2000/// CY - New York PB - W.W. Norton KW - Human evolution N1 - Includes bibliographical references and index ER -