Technology and Intelligence

Wed, 8 Feb 1995 15:18:19 CST

I admire R. Holloway's prescience in not ruling out tool use among
robust australopithecines; but back then it was quite parsimonious to
hope and believe that the gracile form's different--and evidently more
successful--development might be attributable to lesser commitment to
culture in general, toolmaking/tool-use in particular. At any rate, the
new evidence suggests more strongly than ever the great antiquity of
precise manipulation of objects in the hominid line. This seems to have
largely predated brain expansion, and therefore could have been what
tipped strong selection *for* brain expansion. I admit that more is
involved in the evolution of human intelligence than brain expansion;
but one scarcely wants to suggest that a near-tripling of the gray
matter was a peripheral factor! I am puzzled by D. Read's opinion that
the 500 cc brain of the robusts already showed expansion was well under
way. This is only about the size of a chimpanzee's brain. No doubt
reorganization, associated maybe with lateralization and
symbolization--as Holloway's work has suggested--was well under way; but
not expansion. Maybe Dwight is thinking of WT 17000, the "Black Skull,"
which I believe was somewhat smaller than 500cc? Seems to me a slender
basis--one specimen--for concluding that a precision grip did not preced
e expansion. Do you have more evidence, Dwight? --Bob Graber