Page 114 - Encyclopedia Of World History Vol III

human evolution—overview 933

The world began without man, and it will complete itself without him. • Claude Levi-Strauss, (b.1908)

ern Africa between 3 and 2.5 million years ago, giving way shaped to fit immediate needs. Soon after 1.9 million
to a robust group that included Australopithecus aethio- years ago, habilines had at their disposal an array of sim-
picus and then Australopithecus boisei in East Africa and ple but clearly recognizable choppers, scrappers, burins,
Australopithecus robustus in the far south. (Some pale- and hammerstones, all made in set patterns created by
oanthropologists classify aethiopicus, boisei, and robus- striking a core with a smaller stone to chip off a few
tus as members of the genus Paranthropus, which gives sharp-edged flakes. Known as the Oldowan industry, this
some impression of the degree of debate in the field.) basic technique eventually spread throughout much of
Robustus died out about 1.5 million years ago, while boi- Africa and Eurasia, continuing to be practiced in isolated
sei endured for another 500,000 years, at last succumb- areas as recently as 200,000 years ago. Intentionally
ing to less burly creatures with larger brains relative to designed Oldowan tools enabled habilines to broaden
body size and greater dependence on tool use. The ear- their subsistence strategies through increased depend-
liest forms of our genus, Homo, collectively known as ence on meat.While the bulk of their diet still consisted
Homo habilis or “handy man,” were indisputably present of vegetable foods, habilines probably turned with grow-
in East Africa somewhat more than 2 million years ago, ing frequency to opportunistic scavenging of predator
coexisting with Australopithecus boisei for at least a mil- kills and expert tracking of small game animals.
lion years and with robustus in South Africa for a much Although their hunting activities remained limited, they
shorter period. were beginning to define the basic contours of the gath-
ering and hunting adaptation.
Appearance of As the social organization of their bands became
the Genus Homo more complicated, the demands placed on individuals in
What paleoanthropologists have lumped together as their relationships with others may have contributed to
habilines may actually have been several closely related the development of the brain. Manual dexterity, bipedal-
species. At a minimum, some experts insist on differen- ism, and tool use simultaneously showed signs of
tiating Homo rudolfensis from Homo habilis. Others ex- improvement, all evolving together with enhanced men-
plain substantial variations in terms of a pronounced sex- tal capacity.What made the hominid brain truly distinc-
ual dimorphism (that is, pronounced differences in the tive was its division into two asymmetrically structured
physical appearance of the sexes). But all agree that an hemispheres, each containing identifiable areas designed
abrupt species transition apparently did take place about to control particular mental and behavioral functions.
2.6 million years ago, and that the brain size of habilines Among other consequences now vital to our existence,
jumped appreciably around 600,000 years later. But habilines may have possessed a feature of the cerebral
beyond enlarged cranial capacity, Homo habilis remained cortex known as Broca’s area, a region connected with
remarkably apelike. Paleoanthropologists have used the speech in modern humans. Despite an immature larynx,
earliest evidence for systematic tool manufacturing—a which would have limited the range of sounds they
momentous accomplishment that gave birth to the devel- uttered, habilines may have articulated a combination of
opment of culture as a primary adaptive mechanism for vowels and consonants adequate for the exchange of
humankind—as the means for differentiating habilines some genuinely complex ideas.
from australopithecines.
No later than 2.4 million years ago, East African homi- Significance of
nids who may have been the immediate precursors of Homo Erectus
Homo habilis rather suddenly started to modify water- As ever more elaborate cultural innovations augmented
smoothed pebbles and rocks gathered in river beds, biological changes, the pace of hominid evolution quick-
fashioning them into rudimentary stone artifacts suitably ened, starting with the appearance of Homo erectus, a