"However, in Acheulean sites, evidence suggests that transport
occurs more often – and over much greater distances. At Olorgesailie,
Isaac (1977) notes occurrences of quartz brought over 40 km. At
Kilombe, similarly, two obsidian bifaces appear among many hundreds
made from local lavas, and the implication is again that long-distance
transport occurred (Gowlett, 1982). At Gadeb, in eastern Ethiopia,
dated
at about 1.5 Ma, several obsidian bifaces apparently document a
transport
distance of over 100 km (Clark,1980). Thus, the archaeological record
suggests that transport both became more common and occurred over much
greater distances, during the period in which Homo acquired its modern
human-like postcranial skeleton (Wang and Crompton, 2004)."
W.-J. Wang and R. H. Crompton 2004
The role of load-carrying in the evolution of modern body
proportions
J. Anat. 204 pp417–430
"The Turkana boy tells us that early H. erectus, besides being a tall
biped,
had arms and legs proportioned like a modern human's. For his height,
his
arms were not as long as those of Lucy, Lucy's Child or so far as we
know,
any other prior hominid. He lacked the apish details that, in earlier
bipeds,
suggest occasional tree climbing. The legs and hip bones of Homo
erectus
were buttressed by tremendous thickness and bulges, which denotes a
body geared toward endurance walking and running. An exclusive pact
had
been made with the terrestrial realm, and the boy's legs were
equipped to
cover ground in strides protracted in both length and hours."
Richard Potts from Humanity's Descent