Last Ape Standing: The Seven-Million-Year Story of How and Why We Survived Read Online Free PDF

survive were finally getting the hang of living in their new environment, fanning out in more directions, deepening the peculiar evolutionary experiment we call humanity.
    And it
was
an experiment; make no mistake, because not all branches of the human family were evolving along the same lines. More precisely, species were striding down two distinctly different roads—one that included smaller, slimmer, so–called gracile apes, and another that embraced bigger, thicker humans with large jaws and teeth, known in the world of paleoanthropology as robust apes. Each approach had its advantages. But in the long run, only one would succeed.
    The members of the robust branch of the human family first showed their simian faces in late August among the flooded grassland along the Omo River in southern Ethiopia and the western shores of Lake Turkana in northern Kenya. Scientists call this specimen
Paranthropus aethiopicus
, and he is perplexing because he combines so many contradictory characteristics. His bone structure seems to say that he more often than not walked on all fours among the elephants, saber–toothed cats, and hyenas with which he passed his days. Yet he lived in wet, open grasslands munching on tubers and roots with his big, flat teeth and ample jaws, rather than in wooded areas where you might think knuckle–walking would make more sense. Despite his chimplike anatomy and relatively small brain (no more than 450 cc in adulthood), he may have been the first to pull off the astounding trick of fashioning the first stone tools, preceding even the famous feats of “Handyman” (
Homo habilis
), who followed him and is generally considered the inventor of the first Neolithic technology. (Scientists are debating anew who should get credit for this remarkable advance.)

    Whatever
aethiopicus
accomplished, more like him were to follow. Later in the calendar year—the middle of October—two other
Paranthropus
species,
boisei
and
robustus
(also known as
crassidens
in the ever–changing argot of paleoanthropology), arrived, also generously jawed, large headed, and big of tooth, like
aethiopicus
.
    Paranthropus
humans represent an evolutionary “strategy” that modified the behaviors of jungle apes, but didn’t leap dangerously far from them. Of the two routes down which evolution was walking earth’s humans, this was the safer, more conservative one. Like their predecessors in the rain forests, troops of robust apes roamed from location to location, gathering what food they could find in the thinning forests, bush, and grasslands where they lived. Because of the sorts of foods they ate,
Paranthropus
possessed heads that sported thick, sagittal crests like the ones you see on the silver–backed gorillas at your local zoo, though they were more chimp–size than gorilla–size. The crests are a stout, jagged line of bone that runs from the top of the forehead to the back of the neck like the metal rim of a medieval helmet. Anchored to these were thick ropes of muscle that ran to their massive jaws and dense necks so that the broad, square rows of teeth in their mouths could crush the cement–hard shells of the nuts they consumed, pulverize bark and seedy berries, crunch the exoskeletons of large insects, or masticate the bones of an unfortunate small animal they might have been lucky enough to snatch up.
    Beneath these crests the brains of
boisei
and
crassidens
had expanded roughly a third during the four million years that had passed since the first human emerged from Africa’s rain forests. They were undoubtedly resourceful and even more socially bonded than the apes from which they had descended, mostly thanks to the menace that surrounded them. Danger breeds reliance and cooperation. Day–to–day living would have been unimaginably harsh: a life of slow migration, eating to gather the strength to move forward and moving forward to gather more food to eat. Despite its hardships, however, this was by no means an