The foundational
principle that was made by Charles Darwin on which he based most of his
theories including the evolution theory is that any apparent truth should
always be looked at with some level of skepticism (Darwin 134). Darwin in fact
questioned the view that had been previously held by scientists that science
was a set of things and concepts that have been arranged in an orderly manner. Evolution
is termed as a theory since it a model that has developed from observation of a
phenomena and it makes some predictions basing on concepts like natural
selection. On the other hand, evolution can be looked at as a science also a
fact since it has actually been subjected to scientific test and observation (Muller 306).
Before Darwin’s theory saw the light
of day, everyone believed that the organisms that exited were divinely created
in their current form and they could not be changed. Darwin’s suggestion that creatures could in
fact change over time was not taken very well. Darwin’s theory was influenced
by the work of other scientists including his grand father who were trying to
study the source of fossils. The research they were doing led them to believe
that there was a possibility that species evolved over time.
The
year 1809 saw Lamarck Jean, who was a French scientist, develop a theory that
species evolved over generations. He was the first scientist to officially make
the controversial assertion that the size of the different features on the
bodies of an organism was dependent on the frequency of their use. He believed
that the more frequency used features grew larger and got more developed
whereas the less used features grew smaller over the years and would eventually
become unusable. These changes were then transferred to the subsequent
offspring. The scientist however pointed out that the changes were reliant on
the environmental conditions (Hardin 1292).
Darwin’s Observations
While on voyage aboard the beagle,
Darwin realized some things that made no sense unless the concept of gradual
change was used to explain them. For instance, Darwin noticed that the flora
and fauna of Galapagos Island what a lot of similarity with those found in
South America (Browne 376). This was despite the fact
that there was a difference of at least 1000 kilometers of water between the
two lands. The only logical explanation that Darwin came up with was the
species had migrated form one of the locations many years ago and had changed
on reaching their new destination probably as a means of adapting to the new
environment (Browne 376).
Darwin
was well aware that his theory would elicit sharp contention in society and he
was bracing himself for the possibility of its entire rejection. Darwin
therefore made sure that he had gathered substantial evidence for the three premises
that he had suggested. Darwin’s suggestion of the principle of natural
selection was not so hard to understand especially after he made clear the
three pillars on which the concept stood. Darwin suggested that heritability,
variation and over multiplication of the species is what necessitated the law
of natural selection. Darwin suggested that the law of natural selection make
the specie that enjoys a significant level of differential success more likely
to adapt to the changing environments which would therefore make it more likely
to survive for longer while other species were fizzling out.
The
theory of natural selection is based on the fact that each one of the species
has potential for procreation. This notwithstanding, it’s only a countable few
that actually manage to procreate (Behe 34). Darwin observed that
the species that were more adaptive to their environmental changes and demands
held an upper hand over those that were not willing or able to adapt to change.
The organisms that adapted easily to their changing ecosystem were more
successful in procreation and therefore, they survived through the ages. This
concept of differential reproduction rates is what Darwin referred to as natural
selection. As the more adaptive species continue to multiply while the less
adaptive continue to diminish, the more adaptive creatures would eventually
become dominant in the population while the less adaptive would become less and
less represented and over time, they would disappear completely. This eventual
change in the ecosystem over the years is what Darwin referred to as evolution.
One
of the most important observations that Darwin made was that organisms that
lived in different environments had different characteristics. He noted that
the different ecosystems placed different kinds of pressure on the respective organism.
These organisms had no choice but to develop a way of surviving in the given
environment. The concept of developing new features or improving on the already
existent features so as to survive in the environment in the light of the
environmental is what Darwin referred to as adaptation. Adaption is important
to the organism especially in light of natural selection as it gives the organism
a selective advantage (Sachs 1415).
The Proofs
The concept of evolution faced some
hostile reception as it challenged the view that mankind had for centuries.
However there are some four valid considerations that Darwin based his argument
on. For starters, Darwin observed that there existed a lot of variation between
organisms of the same specie. He further explained that these differences in
genes could be attributed to the random mutations that the organisms are
exposed to over time (Coyne 85).
Secondly, Darwin Charles observed
that in the same ecosystem, there was some organism that had an upper hand in
surviving. This he explained was because they were more ready to adapt to their
environment. AS a result, this species had more reproduction rates and were
therefore dominant in the population. The term “survival for the fittest” was used to refer to this concept.
Darwin also observed that an
organism usually beings by developing certain traits that will enable it to
survive in the ecosystem. Once the organism develops these traits, they would
be relayed to the other members of the population over the years. But perhaps
the biggest proof that Darwin had for the theory of evolution is the
explanation of fossils. Fossils were discovered which could only be connected
to creatures that had become extinct many years ago. It was therefore observed
that the current specie has actually evolved from some of the former species (Coyne 86).
Contemporary Discoveries
There have been new findings in
science that have shed more light on the subject of evolution. For instance,
scientists now know that species have hereditary traits that are made possible
due to the gene composition. This implies that certain characteristics are
usually more prevalent within a population due to the fact that more organisms
in the given population have alleles for those forms (Walsh
477).
Simply stated, the theory of natural
selection is the reason behind the increase or decrease in alleles in a given
population. It has also been established that reconstitution of alleles and
mutations which occur during sexual procreation make room for an infinite
number of variants on which natural selection will act on (Shubin 45).
Secondly, experts have observed a
pattern in the procreation of similar species. It has been realized that some
species in the population can not breed with their similar specie as a result
of geographical distance between them. It was further observed that the
organisms of the same specie that had some geographic separation would
continually change over time and eventually, the two organisms would have
become somewhat different as they adapted to different environments.
Eventually, the organisms would not be able to breed again. Scientifically, if
the same species can no longer breed to procreate, then the organisms can not
be said to be of the same specie (Walsh 479).
Modern day Science has also
considered anatomy to try and unravel the mystery of evolution (Soltis 7056). The anatomists discovered that when they
juxtaposed the anatomical makeup of different organism, they realized some
similarities in their structures. One of the main similarities they realized
across the board is the skeletal structure of the organisms. Most had similar
bones although some were more advanced than others probably due to the fact
that some were used more than others. These similarities can be a proof that
the vertebrates have a common ancestry.
The importance of science in the
study of the concept of evolution is that it helps in making simple the complex
issues of evolution. For instance, it would not be easy for a person to get the
analogy between the vertebrates’ skeletal structure. However, with empirical
evidence, it becomes not only easy to comprehend but it also makes sense even to
a layman
Conclusion
Evolution is a concept that stemmed
from observation of the species. The patterns realized were treated not as
coincidences but as part of an intricate design of nature. When Galileo
suggested that the earth was in fact spherical and not flat as had been
previously thought, people were not very amused and his assertion received
hostile reception. In much the same way, Darwin’s theory of evolution was not
taken as gospel truth by many people (Denton 250). But the beauty of
Darwin’s theory is that it is made with some very substantial proofs.
The law of natural selection is
perhaps one of the best explanations to evolution. Species that was more
willing to adapt to the changing environments and the new demands of the
ecosystem eventually increased and become dominant members of the population.
The other organisms that were less adaptive were replaced over time as they
were unable to survive the new environment.
Works Cited
Behe, Michael. Darwin's Black Box. London: Cengage Publishing, 1996.
Browne,
Janet. Charles Darwin: The Power of Place. London: Pimlico, 2003.
Coyne,
Erry. Why Evolution is True. London:Penguin Group, 2009
Darwin,
Charles. On the Origin of Species. London: John Murray,1859.
Denton,Michael. Evolution: A Theory in Crisis. London: Early House 1986.
Hardin,
Glen. The competitive exclusion principle. Science 131:2
(April 1960). 1292–1297.
Muller,
John. One hundred years without Darwin are enough. School Science and Mathematics 59.1 (1959):
304–305.
Sachs,
Jay .Cooperation within and among species. J. Evol. Biol. 19.5 (2006): 1415–1418
Shubin,
Neil. 2008. Your Inner Fish. New York: Pantheon, 2008
Soltis
Phil and Soltis DenishThe role of genetic and genomic attributes in the success
of polyploids. Proc. Natl. Acad.
Sci. U.S.A. 97.1 (June
2000): 7051–7057.
Walsh
Timothy. Combinatorial genetic evolution of multiresistance. Curr. Opin.
Microbiol. 9.4 (2006): 476–482.
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