Humans, as we know them, are products of the last 600,000 years, the
Pleistocene.  This epoch is marked by several ice ages lasting several
hundred thousand years separated by short interglacials of about 10,000
years.

Neanderthals are a type of human (genus homo) that became most prominent
in the first half of the last ice age only to be replaced sudenly by
modern Man (Cro-Magnon) in the last part of the same ice age.

Begining about 127,000 years ago, the earth became warmer for the first
time in over 100,000 years.  It started with what's called an
interglacial period of about 10,000 years and then into the first half of
the last ice age when weather was considerably warmer than a normal ice
age.  This resulted in pushing the enviroment of the pleistocene
mega-fauna into higher latitudes, resulting in longer winters and a
shorter growing season for the grasses of this steppe-tundra.  More
agressive hunting techniques were necessary and man developed the brute
strenth necessary to obtain the fat from the large mega-fauna animals to
survive the long winters.

But another type of human that had first developed in another
interglacial warming period had an edge that eventually won out.  He was
neotenized to the point where he never developed the muscles of a mature
hominid or ape.  This gave him a much lower metabolism (even at rest) and
allowed him to put on fat very rapidly when he ate high carbohydrate
foods during the short fruit season.  This gave him only a slight edge
during hard times, but it was enough to keep his genes in the pool. It
was only when he began associating with another neotinized animal as a
byproduct of his own neoteny, the dog, that he was able to utalize longer
range, lighter weapons.  Freed from the constraints of holding the animal
at bay, thanks to his pack of dogs, he could hurl his weapons from a
safer distance. These new weapons were the great equalizer when it came
to competing with his stronger Neanderthal cousins for food or teritory.
 When the steppe tundra again migrated towards the equator, this new
"super-predator" propagated rapidly overwelming both Neanderthals and the
mega-fauna which both soon became extinct.  When the last interglacial
warming began about 12,000 years man and his dogs pursued the last
mega-fauna animals into the arctic and fron there into the Americas until
they where all gone.  Sea levels rose (see Noah) and the world became
dryer as well as warmer.  What had been man's prime steppe-tundra
enviroment was now dry savannah or forest, much less suitable to high
population denisities of humans.  This diminishing of resources led to
the Neolithic Revolution (The Fall).

Ray Audette
Author "NeanderThin"