 Charles
Darwin, a British naturalist, revolutionized biology with his
theory of evolution through the process of natural selection.
He also made significant contributions to the fields of natural
history and geology. On Nov. 24, 1859, an abstract of Darwin's
theory was published under the weighty title of On the Origin
of Species by Means of Natural Selection, or the Preservation
of Favoured Races in the Struggle for Life. In his account of
how natural selection occurs, known as Darwinism, he pointed
out that not all individuals of a species are exactly the same
but, rather, that individuals have variations and that some of
these variations make their bearers better adapted to particular
ecological conditions. The effect of On the Origin of Species
was immediate and widespread. The book upset many established
patterns of thought, contradicted firmly held religious tenets,
and brought into focus the concept that humans are one species
among many that had evolved from preexisting forms. Debates on
the theory raged all over England, Europe, and the United States.
As recently as 1925, Darwin's theory of evolution created such
furor that it culminated in the famous Scopes trial in Tennessee.
Even today legislators debate whether this scientifically sound
fact should be part of the public school curriculum.
Darwin suggested that Africa would turn out to be the home of
humanity. As science progressed it proved him correct. Between
5 and 6 million years ago Africa was drying up. The great lush
forests of Central Africa retreated into little islands surrounded
by deserts. The primates who were dependent on sheltering in
the trees or dependent on fruits and leaves as food were dramatically
affected by this. These islands ran out of food and the next
trees were miles away on the other side of the plain. Pressure
was on these creatures caught in the little islands to adapt
or die out. Success ment providing for your offspring. And any
behavior that would make those offspring more likely to survive
would be strongly selectively favored. If a male were to collect
highly valued items of food and provide them to a female, it
would greatly improve the chance of survival for the group and
the infant. It would be an intensely favored form of adaptation.
But that form of adaptation required walking upright to carry
food items over long distances. Adopting upright locomotion (bipedalism)
improved our reproductive rate and our survivability. Bipedalism
was a major evolutionary advance and required many modifications
to the bones and muscles. It was probably accompanied by other
changes such as hair loss and better sweating mechanisms. How
many thousands of years it took to accomplish all these changes
is unknown. But if the changes were critical for survival, the
transition in evolutionary terms could have been very rapid.
One of the great driving forces of evolution is the daily search
for food. Every species is going to adapt to anything that helps
them eat and stay alive. Early hominids came down from the trees
and were faced with a deterioration of their normal food sources.
They also had a number of biological limitations compared to
other animals. They couldn't dig underground like elephants do
with their feet for food or water. Hominids didn't have the large
chewing teeth and bone crushing jaws of a hyena. But to live
and reproduce you have to find a way of muscling in on the system.
It is very possible that their niche was found as a scavenger
in bone marrow processing. When they came across carnivore kills
where most of the meat had been eaten, they were left with only
the bones. They could get into those bones and access the very
rich fat and protein sources with simple anvil technology.
The next step in early stone technology was stone flake tools.
The small stone flakes are probably the most important idea in
the history of mankind. They made up for some of the handicaps
the hominids faced in their vital search for food. The stone
flakes replaced the sharp carnivores canine teeth that the hominids
lacked. Early hominids were not a dominate species like us. You
have to forget how much we're in control. Our ancestors were
just another species of animal fighting for survival on the open
plains. Carnivores were more numerous and much faster and better
equipped for predation than this little bipedal hominid. They
had to find nourishment where they could and the new tool gave
them an edge. When they came across a dead carcass on the landscape
they could move right in, get through the skin and get a good
quantity of meat very quickly. The speed was necessary because
there were other animals out there seeking the same carcass.
Animals that were faster, had sharper teeth and were much more
threatening. The early hominids probably didn't hunt much. They
ate meat from carcasses of animals that had been killed by predators
or even died by accident. They were probably eating the meat
raw. This is commonly done in the primate world by chimpanzees
and baboons.
The success of the early tools led to more sophisticated ones.
Hand axes were the inventions of Homo erectus about 1.5 million
years ago. Suggested by the great variation in size, thickness
and form they were probably used for a variety of purposes including
rapid dismemberment. It is referred to as the swiss army knife
of the paleolithic. Hand axes were the dominate form of human
technology for over a million years.
From the beginning of tool use we needed to teach our children
many things. Language gave us the means by which we could achieve
this. We needed to teach them which were the best materials for
the tools, how to make them and how to use them effectively.
If you can't teach these things to your children they have no
evolutionary significance. If you can teach them and pass them
on they will affect the future of the species. As our population
increased our ancestors started living in progressively larger
groups. Culture became more complex and we needed a language
to transmit the culture to the offspring. We needed to work out
relationships between individuals. Language is a sort of social
glue. It breaks barriers, makes friendships, solves disputes
and enables us to make plans. Language also gives us the ability
to make symbols of our lives through art, sculpture and decoration.
Today language is complicated. But it came to us like everything
else, to enable us to survive as groups of creatures on the African
Savannah. Language has some remarkable properties. It was language
that enabled us to educate ourselves and our offspring. And this
activity evolved some very important changes in the human brain.
The very process of educating restructures the brain. The more
complex our culture became, the bigger our brains became.
Approximately 55% of Americans deny
human evolution. They
portray it in a negative manner. They claim it is ordinary, random
and leaves one lacking purpose in life. In reality human evolution
invites an enlightened and quite fulfilled understanding of our
position in the natural world. It is a wonderful process by which
humans have come to exist. Although the concept of evolution
is common, the path we took as humans is remarkable and unique.
It should be revered not reviled. Real purpose and understanding
is found in reality. |
