About 2.5 million years ago, a sudden change in climate spurred the evo-
lution of the first humans.The drying of the African climate caused an increase
in grasslands at the expense of forests, where human ancestors probably found
food, shelter, and refuge from predators.With the stress of life on the open savan-
nah, early humans might have developed larger brains, which gave rise to tool-
making skills and cooperative hunting techniques in order to survive.
The most successful of the early hominids was Homo habilis, which
evolved a little more than 2 million years ago. It was a species in transition
between primitive apelike hominids and early humans. Its brain was about half
the size of that of modern humans. The limb bones were markedly different
from earlier hominids and more closely resembled those of later humans. It
was the first human species to make and use tools. It had well-developed
speech centers, indicating a primitive language capability.
Homo habilisdisappeared from Africa around 1.8 million years ago and
was replaced by Homo erectus,the first human ancestor to have departed Africa.
This species is widely accepted as human and appears to have evolved in
Africa directly from Homo habilis.It could hav e also evolved independently in
Asia and subsequently migrated to Africa. About 1 million years ago, this early
human occupied southern and eastern Asia, where it lived until about 200,000
years ago. Its advanced features suggest a spurt of evolutionary development,
as it shares many attributes of modern humans. Its brain was also larger, about
two-thirds the size of a modern human’s.
Many types of Homo erectus were scattered throughout the world. This
suggests that anatomically modern humans evolved from this species in sev-
eral places, possibly accounting for the differences in races among people
today. Peking man, a variety of Homo erectusthat lived in China about 400,000
years ago, dwelled in caves and was possibly the first to use fire. Another vari-
ety, called Java man, arrived in Java about 700,000 years ago. About 60,000
years ago,the descendants of Java man migrated to Australia and possibly other
South Pacific islands.
The earliest Homo sapienswere called Cro-Magnon, named for the Cro-
Magnon cave in France, where the first discoveries were made in 1868.They
originated in Africa perhaps 200,000 years ago. Evidence also suggests they
arose simultaneously in several parts of the world, as much as 1 million years
ago, possibly evolving directly from Homo erectus.The Cro-Magnon shared
most of the physical attributes of modern humans.The skull, whose brain case
proportions were modern in structure, was short, high, and rounded. The
lower jaw ended in a definite chin. The rest of the skeleton was slender and
long limbed compared with earlier human species.
Sometime in the last ice age,Cro-Magnon appears to have advanced
into Europe and Asia during a warm interlude when the climate was less
severe.They probably lived much like present-day natives of the Arctic tundra,
QUATERNARY GLACIATION