(The present, shallow Bering Strait, separating Siberia from Alaska,
alternated between a strait and a broad intercontinental bridge of dry
land, as sea level repeatedly rose and fell during the Ice Ages.)
However, boat building and survival in cold Siberia were both still far
beyond the capabilities of early Homo sapiens.
After half a million years ago, the human populations of Africa
and western Eurasia proceeded to diverge from each other and from
East Asian populations in skeletal details. The population of Europe
and western Asia between 130,000 and 40,000 years ago is
represented by especially many skeletons, known as Neanderthals and
sometimes classified as a separate species, Homo neanderthalensis.
Despite being depicted in innumerable cartoons as apelike brutes
living in caves, Neanderthals had brains slightly larger than our own.
They were also the first humans to leave behind strong evidence of
burying their dead and caring for their sick. Yet their stone tools were
still crude by comparison with modern New Guineans' polished stone
axes and were usually not yet made in standardized diverse shapes,
each with a clearly recognizable function.
The few preserved African skeletal fragments contemporary with
the Neanderthals are more similar to our modern skeletons than to
Neanderthal skeletons. Even fewer preserved East Asian skeletal
fragments are known, but they appear different again from both
Africans and Neanderthals. As for the lifestyle at that time, the best-
preserved evidence comes from stone artifacts and prey bones
accumulated at southern African sites. Although those Africans of
100,000 years ago had more modern skeletons than did their
Neanderthal contemporaries, they made essentially the same crude
stone tools as Neanderthals, still lacking standardized shapes. They
had no preserved art. To judge from the bone evidence of the animal
species on which they preyed, their hunting skills were unimpressive
and mainly directed at easy-to-kill, not-at-all-dangerous animals. They
were not yet in the business of slaughtering buffalo, pigs, and other
dangerous prey. They couldn't even catch fish: their sites immediately
on the seacoast lack fish bones and fishhooks. They and their
Neanderthal contemporaries still rank as less than fully human.
Human history at last took off around 50,000 years ago, at the
time of what I have termed our Great Leap Forward. The earliest
definite signs of that leap come from East African sites with
standardized stone tools and the first preserved jewelry (ostrich-shell
beads). Similar developments soon appear in the Near East and in
southeastern Europe, then (some 40,000 years ago) in southwestern
Europe, where abundant artifacts are associated with fully modern
skeletons of people termed Cro-Magnons. Thereafter, the garbage
preserved at archaeological sites rapidly becomes more and more
interesting and leaves no doubt that we are dealing with biologically
and behaviorally modern humans.
Cro-Magnon garbage heaps yield not only stone tools but also
tools of bone, whose suitability for shaping (for instance, into
fishhooks) had apparently gone unrecognized by previous humans.
Tools were produced in diverse and distinctive shapes so modern that
their functions as needles, awls, engraving tools, and so on are
obvious to us. Instead of only single-piece tools such as hand-held
scrapers, multipiece tools made their appearance. Recognizable
multipiece weapons at Cro-Magnon sites include harpoons, spear-
throwers, and eventually bows and arrows, the precursors of rifles and
other multipiece modern weapons. Those efficient means of killing at
a safe distance permitted the hunting of such dangerous prey as rhinos
and elephants, while the invention of rope for nets, lines, and snares
allowed the addition of fish and birds to our diet. Remains of houses
and sewn clothing testify to a greatly improved ability to survive in
cold climates, and remains of jewelry and carefully buried skeletons