The significance of changes in body mass in human evolution

Body mass changes in the Hominini are examined from an evolutionary perspective. Among the conclusions drawn from this examination are the following: 1.) hominids (sensu lato) are among the largest and most terrestrial primates; 2.) early Homo is on average larger in size than Australopithecus (although the two taxa do show some size overlap); 3.) following its emergence in the early Pleistocene, Homo shows a steady increase in body mass, reaching its maximum near the end of the middle Pleistocene; 4.) Homo subsequently decreases in size throughout the late Pleistocene and into the Holocene, only to increase in size again very recently (the so-called “secular trend”); 5.) body mass variation among humans today tends to follow well-known ecogeographical “rules”, which are empirical observations with multiple potential theoretical explanations.