It has also been suggested that the Athabascans may have sailed
across the Bering Strait in boats because it is thought that they
are later arrivals than the other natives.
Furthermore, at least one professional theorizes that even the
earliest American immigrants may have kept close to the coast where
food would have been more plentiful than inland on the Bering
Strait land/ice bridge. Such people, he speculates, may have been
maritime folks who used boats along the coast. (Sorry I forgot his
name.) If true, this would help explain why the west coast was
more highly populated than other parts of America north of Mexico.
On parallel evolution of Homo sapiens, I think it is possible,
though not necessarily probable, that H. sapiens evolved in both
Asia and Africa, maybe even Australia. The immediate ancestor
of H. sapiens was H. erectus and the next ancestor was H. habilis.
H. habilis could survive only in the tropics of Africa and Asia,
but H. erectus was able to go into the colder climates of Europe
and China, but not into the frozen lands. H. erectus even made it
to Australia and islands of Indonesia. Java Man and Peking Man
were H. erectus.
It took the greater abilities of H. sapiens to survive in tundra
regions, and ultimately to cross into the American continents.
Neanderthal, Cro-Magnon, Swanscombe and several others are
variations or subspecies of H. sapiens.
It is accepted that H. sapiens could not have evolved in America
because have never been any H. erectus fossils found, nor
H. habilis. All Homo fossils found in the Americas have been
H. sapiens.
Stephen Jay Gould was probably referring to the dispute for
H. sapiens origins in Africa, Asia or Australia, since H. erectus
was present in all three places. Traditional theory is that
H. sapiens evolved from H. erectus in Africa, and then went to
Asia, Europe and Australia to displace H. erectus from those
places, just as H. erectus had once come from Africa to displace
H. habilis in several places.
There have also been speculations that the H. sapiens mutations
could have happened simultaneously in more than one place. When I
look at the incidence of some benign mutations today, I feel that
parallel evolution is possible. For example, look at the number of
people with Down's syndrome and dwarfism.
Unfortunately, some people with racist agendas have tried to use
the parallel possibility to support arguments that so-called races
of humans are more distinct than they really are. The fact is,
H. sapiens has been so mobile and so interested in reproduction
that the human species is remarkably homogeneous throughout the
world despite *perceived* differences. Although skin color *seems*
significant because it is all over a person and has obvious
survival value depending on latitude, it is determined by a tiny
number of genes. Even if there were parallel mutations leading to
H. sapiens in Asia, Africa and Australia, the resulting people
would be the same, just as an Asian person with Down's has the same
mutation as an American with Down's.
Nevertheless, the potential racism aspect of the parallel
hypothesis has probably made it less popular than the African
hypothesis.
There are also theories about people sailing from Asia or Africa
before Columbus. Such things are *possible* but could not have
happened on any *grand* scale without there being more evidence.
In other words, maybe a few Polynesians or Egyptians did sail to
America, but not enough to have significantly contributed to the
American cultures. The best evidence indicates that the Mayan
pyramids, Mexican pottery and Inca metallurgy are all independent
inventions accomplished by Native Americans, not brought by
immigrants. In this case, it is certain that parallel inventions
were made. It's not too surprising. Arches work well in
architecture in Egypt, Europe and ancient America. Stairs and
ladders are methods for allowing multi-story buildings. Fluted
pottery reflects a design found in nature, in melons, for instance.
But the most creative designs, those with no utilitarian purpose,
are so distinctive that no one would ever confuse an ancient
Japanese painted clay bowl with one from ancient Egypt or one from
the ancient Pueblos of America.
Trying to discredit Native American accomplishments has been an
historical past time. Some people would even rather believe that
aliens from space were responsible for the geometrically complex
effigy mounds! But more recently it has been accepted that Native
Americans did have mathematical techniques advanced enough to allow
them to develop calendars, astronomical/seasonal predictions,
pyramids and effigy mounds.
Krista