|
There are many different life forms on earth. New species and different sub
species are evolving every second as others die out. In order to explain the
origin of life, people have used the bible story of creation, while others came
up with their own theories. Out of all those theories, the theory of evolution
by Charles Darwin seems to have the most supporting evidence to back it up.
Evidence on earth suggests that single cell creatures are the ancestors of all
life.
These organisms slowly evolved into air breathing creatures when oxygen was
created. Slowly, the as land dried up, these creatures moved away from the water
and on to land where they evolved legs and a strong back bone. The theory of
evolution by Charles Darwin explained how life evolved from survival of the
fittest, it provides a logical explanation of the evolutionary process these
creatures took, and how human came to be. Evidence on earth shows that single
cell organisms eventually evolved to multicelled organisms and complex beings.
If you look at old fossil records, the oldest fossils are all single cell
creatures. These simple creatures do not require oxygen to live. It took in
energy from the sun and other energy sources.
Slowly as oxygen begins to appear on Earth, some of the organisms began to
evolve lungs to breathe oxygen because When free oxygen entered the picture.
Breathing is more efficient than drawing energy from the fermentation process
that earlier microscope life used. (Science: Biology Pg. 36) Other organisms
that did not evolve lungs either died out or went down to deeper depths of the
ocean; Oxygen was first consider a pollutant by microscopic creatures.
(Evolution Pg. 36) Because of the free Oxygen those who did not change were
killed. The evolution through natural selection and survival of the fittest
shows that Darwin theory is correct. Due to the lack of oxygen within the ocean
, fish slowly evolved to the condition of land. Due to the sudden increase in
the population of fish and other marine organism. Due to the sudden increase in
the population of marines life, the oxygen level within the ocean decreased.
Scientist believe that the lung fish evolved because of a lack of oxygen in
the sea. The lung fish learned to rise from the sea and breathe in the oxygen
necessary for survival. (Evolution evidence Pg. 38) As more land emerges and
dry, rain collected and formed fresh water lakes and rivers. Some of the fish
became stranded by the receding ocean. Many fish that became stranded died
because they were not able to adapt to the new environment; those fish needed
salt water to lived died. But some adapted to their environment. (Evolution Pg.
38) The lobe fin fish was another evolutionary path fish toke to avoid the lack
of oxygen in the sea. Fossil record shows that lobe finned lung fish took
another evolutionary path.
(Microsoft Encarta Pg. 2) The lobe fin fish was
almost capable of leaving the water. It only needed more muscles in the joints
to be able to lift it self up, because of this many people believe that the lobe
fin fish was the ancestor of early reptilian creatures. The different
evolutionary paths the fish have taken shows that life changes in responses to
different environmental conditions. Fossil records in South America, reveals
that there are many sub species of the human race. The fossil of Neanderthal man
was discover shortly after Darwin published his book on evolution..
The
Neanderthal man was consider to be an ancestor of mankind because of the size of
the skull which suggested that it had a small brain. The sloping forehead is
also an indication that it is a ancestor of the human race. Not long after the
discovery of the Neanderthal was found in the 1890's. This fossil was called the
Java Man, the Java Man was not consider the missing link between humans and
apes. (Evolution Pg. 102) The Java Man was too alike a normal human to be the
missing link. The missing link is a fossil of a creature that is in a
transitional state between it original form and it new form.(I.e. A dinosaurs
with feathers) With the discovery of Lucy in South America it was concluded that
Human were likely descendent of the Ape family. The unique thing about Lucy was
that it skeletal structure was almost complete. From the bones, scientist can
tell that Lucy was about three and a half feet tall and weighted about sixty
pounds. (Evolution evidence Pg. 48) Lucy looked like a human from a far but up
close, Lucy still had the appearance of an ape.
|