TY - JOUR T1 - Ultimate causes and the evolution of altruism JO - BEHAV ECOL SOCIOBIOL PY - 2011/03/01 AU - Marshall JAR ED - DO - DOI: 10.1007/s00265-010-1110-1 VL - 65 IS - 3 SP - 503 EP - 512 Y2 - 2024/12/22 ER -