180 CHAPTER 8 | Early Homo and the Origins of Culture
the brain’s energy demands on a vegetarian diet, but the
overall energy content of a given amount of plant food is
generally less than that of the same amount of meat. Large
animals that live on plant foods, such as gorillas, spend all
day munching on plants to maintain their large bodies.
Meat eaters, by contrast, have no need to eat so much, or
so often. Consequently, meat-eating bipeds of both sexes
may have had more leisure time available to explore and
manipulate their environment.
The archaeological record provides us with a tangible
record of our ancestors’ cultural abilities that corresponds
with the simultaneous biological expansion of the brain.
Tool making itself puts a premium on manual dexterity,
precision, and fine manipulation (Figure 8.2). Stone tools
provide evidence of handedness that bespeaks specialization
and lateralization of the brain associated with language.
Beginning with the appearance of the genus Homo in
Africa 2.5 mya, increasing brain size and increasing cul-
tural development each presumably acted to promote the
other. The behaviors made possible by larger brains con-
ferred advantages to large-brained individuals, increas-
ing their reproductive success. Over time, large-brained
individuals contributed more to successive generations,
so that the population evolved to a larger-brained form.
Natural selection for increases in learning ability thus led
to the evolution of larger and more complex brains over
about 2 million years.
Though it preceded increases in brain size by several
million years, bipedalism set the stage for the evolution of
large brains and human culture. It freed the hands for ac-
tivities such as tool making and carrying of resources or
infants. This new body plan, bipedalism, opened new op-
portunities for change.
Figure 8.2 A power grip (left) utilizes more of the hand
while the precision grip (right) relies on the fingers for control,
requiring corresponding organizational changes in the brain.
Homo erectus
In 1887, long before the discovery of Australopithecus
and early Homo in Africa, the Dutch physician Eugenè
Dubois set out to find the missing link between humans
and apes. The presence of humanlike orangutans in the
Dutch East Indies (now Indonesia) led him to start his
search there. He joined the colonial service as an army
surgeon and set sail.
When Dubois found fossilized remains consisting of
a skull cap, a few teeth, and a thighbone at Trinil, on the
island of Java, the features seemed to him part ape, part
human. The flat skull with its low forehead and enormous
brow ridges was like that of an ape; but at about 775 cubic
centimeters it possessed a cranial capacity much larger than
an ape’s, even though small by modern human standards.
The femur, or thighbone, was clearly human in shape, and
its proportions indicated the creature was a biped. Believ-
ing that his specimens represented the missing link and
that the thighbone indicated this creature was bipedal,
Dubois named his find Pithe canthropus erectus (from the
Greek pithekos meaning “ape,” anthropus meaning “man”)
or “erect ape-man.” Dubois used the genus name proposed
in a paper by the German zoologist Ernst Haeckel, a strong
supporter of Darwin’s theory of evolution.
As with the Taung child, the first australopithecine
discovered in the 1920s, many in the scientific commu-
nity ridiculed and criticized Dubois’s claim, suggesting
instead that the apelike skull and humanlike femur came
from different individuals. Controversy surrounded these
specimens throughout Dubois’s lifetime. He eventually re-
treated from the controversy, keeping the fossil specimens
stored safely under the floorboards of his dining room.
Ultimately, the discovery of more fossils provided enough
evidence to fully support his claim. In the 1950s, the Trinil
skull cap and similar specimens from Indonesia and China
were assigned to the species Homo erectus because they
were more human than apelike.Fossils of Homo erectus
Until about 1.8 mya, Africa was the only home to the bi-
pedal primates. It was on this continent that the first bipeds
and the genus Homo originated. It was also in Africa that the
first stone tools were invented. But by the time of H. erec-
tus, members of the genus Homo had begun to spread far
beyond their original homeland. Fossils of this species are
now known from a number of localities not just in Africa,
but in China, western Europe, Georgia (in the Caucasus
Mountains), and India, as well as Java (Figure 8.3).
Although remains of H. erectus have been found in
many different places in three continents, “lumpers,”
as discussed in the last chapter, emphasize that they are