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Evolution of Land Animals
No one knows for sure how life began, whether life came about by an invisible man in
the sky, or by what Darwin (and scientists today) predicted, that life formed from a "hot
little pool" of matter and slowly evolved over time into what we know as life today.
According to evolution, all life or most of it, originated from a single gene. The evolution
of land animals is still studied today, including elephants, giraffes, and horses. Which are
giving us greater clues to how existence started. Let us first establish that all life on earth
© both animal and plant © is constructed of exactly the same substance: DNA.. By DNA
we mean the chromosomes that are found in all living cells. The question philosophers
and scientists have wondered is, then, how the first molecule arose.
Scientists believe that the earth was formed 3.5 billion years ago. This is when it is
believed that life first began. The world did not look like it does today. It contained no
oxygen. It is unlikely that life cells could have risen from a world containing oxygen
because it was highly reactive. Therefore, DNA molecular cells had to be oxydized. This
is how we know that no new life arises today. All life on earth must be exactly the same
age. Science today shows us that an elephant is just as old as a human, because each cell
in our body carries the same hereditary material. The whole recipe of who we are lies
hidden in each tiny cell.
Darwin is considered the father of evolution. We would not be discussing evolution if it
were not for him. His theory consisted of two main points: first he proposed that all
existing vegetable and animal forms were descended from more original and primitive
forms by a way of biological evolution. Secondly, that evolution was the result of natural
selection. He proposed that all living things on earth are related. When Darwin set sail on
the Beagle, he had with him the first volume of the English biologist Sir Charles Lyell's
Principles of Geology. Lyell had the belief that the present geology of the earth was the
result of a long and gradual evolution. His point was the small changes could cause huge
geological upheavals, considering if it is given enough time. The age of the earth was
thought to be only 6,000 years old, which would make the theory incorrect. Darwin
figured the age of the earth was 300 million years old, we know now that the earth is 3.5
billion years old.
When he went on his voyage around the world and came to the Galapagos Islands, he
noticed that there were no great differences in the plant and animal life there. But Darwin
was interested in the tiny differences. On the island he came across large tortoises that
were slightly different from one island to another. Even more striking was that the
finches on the island were clearly different from island to island, especially in the shape
of the beak. Darwin figured these differences were due to the way the finches found food.
The ground finches with steeply profiled beaks lived on pine cone seeds, the little warbler
finches lived on insects, and the tree finches lived on termites extracted from bark. Each
and every beak was perfectly adapted to the food intake. Could all these finches be
descended from the same species? Had they adapted to there surroundings causing them
to evolve? Darwin came to conclusion that yes, they had adapted to their surroundings,
and finches did come from one common ancestor. There were also finds of large fossil
bones from extinct animals. Darwin was puzzled to find traces of sea creatures far inland.
Some believed that they had been thrown there by humans or animals. Others believed
that God had created these fossils and traces of sea creatures to lead the ungodly astray. It
was thought by some that fossils were imprints of animals that had failed to get in the
Ark.
But, there was one more factor to indicate that all the animals on earth might be related:
The development of the embryo. All animal and human embryos are so identical it is hard
to tell the difference. You cannot distinguish a human embryo from a dog embryo.
Shouldn't this indicate that we are distant relatives?
In many animals gene flow occurs. Gene flow is when new genes are introduced to
populations. The Lake Erie water snake provides an excellent example. Some of these
snakes that live on vegetation live close to the shore. They have gray bodies with black
bands which helps them distract hungry seagulls by blending in with the environment.
Island snakes are light gray and have no bands, which helps them blend in with their
environment. Island snakes are light gray and have no band, which help them blend in
with the rocks. Another example is the giraffe. Some scientists used to think that the long
neck was their because the giraffes have always had to reach upwards. Darwin believed
that the giraffe's long neck was the result of variation. He figured that random changes in
heredity caused some giraffes necks to be small and some to be shorter. When there was
a limited supply of food, the giraffe that could reach up the highest had a better chance of
survival.
Fifteen million years before the direct ancestors of modern day horses existed, at least
three species of horses roamed the forests and grasslands of Florida. They lived along
other strange and now extinct creatures such as antelope-like creatures with sling-shot
antlers, and the "bear dog." A medium-sized horse from 18 million years ago weighed
75-100 pounds©about the size of a large dog. The dwarf horse weighed about 30-40
pounds. An amateur digger found the first skull in Florida of a tiny dwarf horse.
It is believed that 50-60 million years ago, mammals were thought to be the size of a pig.
Elephants are thought to have come from those "pigs." Interestingly, it is believed that
manatees, dugongs, and hyraxes are the closest living relatives of today's elephants. The
order under which Elephants are classified is the Proboscidea. The earliest member of
this are the Moeritheres. They are a pig sized creature that lived in northern Africa
between 55-60 million years ago. A little later the Palaeomastodons, who existed between
40-25 million years ago branched off and later evolved into elephants.
Evolution refers to changes that occur in a population over time. It does not indicate that
there is no God. For many various religious groups, evolution is consistent with there
beliefs. For some people, mostly Christians, view evolution as a conflict with their
beliefs. How can you prove creation or evolution? You cannot prove them with science.
If you believe that the Bible is correct, then God created everything. Creation is much
harder to prove scientifically. There are events in the Bible such as Noah's flood. There
would be no way that animals such as those who live in Australia to make there way to
the middle east to be loaded on board the ark. Religion and Science have been in conflict
with one another on the debate of Evolution vs. Creation. I do believe evolution in land
animals did happen, with all the evidence we have it is hard not to. But to believe that we
came from monkeys is harder to believe. I am uncertain whether humans are an exception
to evolution. I do know that us humans have evolved. The Vikings who used to beat and
rape, and were tough men were only 5 foot tall at the most. Therefore the average height
has increased.
It is hard to talk about evolution because the person whom you are talking to may have
different beliefs. There has been controversy whether evolution should be taught in some
schools. Some people believe only in creation, or only in evolution. Most schools by
federal law prohibit the teaching of creation because of the separation of church and state
which is the law. Shouldn't us students have the right to learn all possibilities, and learn
both evolution and creation? I believe that by teaching evolution in school, children can
learn to make up their own minds on what to believe, instead of having be restricted to
one kind of belief system.
What I found to be most interesting is that diseases such as T.B. becomes resistant to
antibiotics, proving the evolution of bacteria. The strongest survive and then reproduces,
causing this reaction. Diseases such these are hard to find cures for, and are often fatal.
All animals are related, by which Darwin described as The Tree of Life. Animals evolve
just like bacteria, using a process called natural selection © "survival of the fittest."
Evolution is a slow process © using several thousands of years to complete. This is why
it is such a hard theory to prove.
You cannot prove either creation nor evolution. They are both good theories on how
humans and animals have come into existence. It is what you believe. I think you have to
ask yourself whether you believe in faith or in logic.
Sources:
http://www.cnn.com/TECH/9601/fossil_horse/
http://elephant.elehost.com/About_Elephants/Stories/Evolution/evolution.html
http://allsands.com/science/creationvsevol_vta_gn.htm
Keywords:
evolution land animals knows sure life began whether life came about invisible what
darwin scientists today predicted that life formed from little pool matter slowly evolved
over time into what know today according evolution most originated from single gene
evolution land animals still studied today including elephants giraffes horses which
giving greater clues existence started first establish that earth both animal plant
constructed exactly same substance mean chromosomes that found living cells question
philosophers scientists have wondered then first molecule arose scientists believe earth
formed billion years this when believed first began world look like does contained
oxygen unlikely cells could have risen from world containing oxygen because highly
reactive therefore molecular cells oxydized this know arises earth must exactly same
science shows elephant just human because each cell body carries same hereditary
material whole recipe lies hidden each tiny cell darwin considered father would
discussing were theory consisted main points proposed existing vegetable animal forms
were descended more original primitive forms biological secondly result natural selection
proposed living things related when darwin sail beagle with volume english biologist
charles lyell principles geology lyell belief present geology result long gradual point
small changes could cause huge geological upheavals considering given enough time
thought only years which would make theory incorrect figured million years know billion
when went voyage around world came galapagos islands noticed there were great
differences plant animal there interested tiny differences island came across large
tortoises slightly different island another even more striking finches island clearly
different especially shape beak figured these differences finches found food ground
finches with steeply profiled beaks lived pine cone seeds little warbler lived insects tree
lived termites extracted bark each every beak perfectly adapted food intake could these
descended species they adapted there surroundings causing them evolve conclusion they
adapted their surroundings come common ancestor also finds large fossil bones extinct
animals puzzled find traces creatures inland some believed they been thrown humans
others believed created these fossils traces creatures lead ungodly astray thought some
fossils imprints failed more factor indicate might related development embryo human
embryos identical hard tell difference cannot distinguish human embryo embryo shouldn
this indicate distant relatives many gene flow occurs gene flow genes introduced
populations lake erie water snake provides excellent example some snakes live vegetation
live close shore have gray bodies with black bands which helps them distract hungry
seagulls blending environment snakes light gray bands helps them blend their
environment snakes light gray band help blend rocks another example giraffe used think
long neck their because giraffes always reach upwards giraffe long neck result variation
figured random changes heredity caused giraffes necks small shorter limited supply food
giraffe reach highest better chance survival fifteen million before direct ancestors modern
horses existed least three species horses roamed forests grasslands florida along other
strange extinct creatures such antelope like sling shot antlers bear medium sized horse
million weighed pounds about size large dwarf horse weighed about pounds amateur
digger found skull florida tiny dwarf horse mammals thought size elephants come those
pigs interestingly manatees dugongs hyraxes closest living relatives elephants order under
classified proboscidea earliest member moeritheres sized creature northern africa
between little later palaeomastodons existed between branched later evolved into refers
changes occur population over time does indicate many various religious groups
consistent beliefs people mostly christians view conflict beliefs prove creation cannot
prove science believe bible correct then created everything creation much harder prove
scientifically events bible such noah flood would such those live australia make middle
east loaded board religion science been conflict another debate creation believe land
happen evidence hard monkeys harder uncertain whether humans exception humans
evolved vikings used beat rape tough only foot tall most therefore average height
increased hard talk person whom talking different beliefs been controversy whether
should taught schools people only most schools federal prohibit teaching separation
church state shouldn students right learn possibilities learn both teaching school children
learn make minds what instead having restricted kind belief system interesting diseases
becomes resistant antibiotics proving bacteria strongest survive then reproduces causing
reaction diseases find cures often fatal related described tree evolve just like bacteria
using process called natural selection survival fittest slow process using several
thousands complete theory cannot either both good theories come into existence think
yourself faith logic sources http tech fossil http elephant elehost stories html http allsands
creationvsevol
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