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Nick Wright
Anthropology
Research Report
Charles Darwin’s Theory of Natural Selection
Charles Darwin is known for his major contributions to evolutionary science, primarily
for his development of the theory of evolution. A critical part of his theory of evolution is the
concept of natural selection, which states “those individuals with favorable variations would
survive and reproduce, but those with unfavorable variations would not”. The purpose of this
paper will be to give a brief history of Charles Darwin, details on his discovery to the Theory of
Natural Selection, and then finally an analysis of how the theory can affect a species, and a
specific example of natural selection occurring.
Charles Darwin was born on February 12, 1809 in Shrewsbury England, to a family of
wealth and higher education. Originally he had planned to follow in his father’s footsteps to
practice medicine, but the medical field didn’t capture his interest well enough to pursue this
endeavor. From there, he enrolled at Christ’s College of Cambridge to study theology, were he
didn’t feel satisfied with this field of study either. After leaving Cambridge in 1831, this is where
his journey towards becoming a naturalist and an exploratory scientist first began. John Henslow,
Professor of Botany at Cambridge, had recommended him for a position on a British Navy
survey vessel, known as the HMS Beagle. This opportunity began his famous 5 year voyage, in
which he sailed to South America, as well as other islands in the Pacific Ocean including the
Galapagos Islands.
The journey to the Galapagos Island’s is known as a major influential factor that helped
guide Darwin to develop his theory of Natural Selection. It was here, that Darwin began to make
observations of the large variation in vegetation and animal species. He began to notice slight
differences in traits from species located on isolated islands, compared to species he studied on
the South American mainland. His big break through came from studying the similarities and
differences between traits of birds from island to island, specially finches. It was here in the
Galapagos Islands off the coast of Ecuador that Darwin collected 13 different types of finches, to
analyze the differences and similarities based on geographic location. He was interested in the
fact that the finches were similar enough to be categorized in a related group, but still showed
distinguishable different physical traits like beak size and shape, that differed depending on
which island or mainland they were collected from. The research he gathered from further
analysis of the Galapagos finches lead him to realize that the finches must have descended from
a common ancestor, but somehow overtime their traits had changed in accordance to what made
them more capable to survive in a specific environment. Along this journey, he also made notes
discussing two different types of iguanas that had appeared to have evolved from the same
species, each one possessing specific traits allowing them to survive in their different types of
habitats. It was from these observations that Darwin realized that certain individuals had a
variation that gave them an advantage, this advantage allowed them to successfully reproduce
and pass the traits on to their offspring’s. This is where the origins of Natural Selection occurred,
and Charles Darwin began to work toward an evolutionary break through (Darwin 27-28).
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Natural selection in its simplest form is survival of the fittest, stating that when change in
an environment occurs, those individuals that posses a “better” trait will survive and the others
will die out. This overtime will eventually lead to the formation of a new species. This process of
natural variation of traits is not to be confused with, artificial selection, which is when humans
manage the process of selecting preferable traits to be reproduced within a species. The basic
process of natural selection works under the idea that in any species, more individuals are
produced by reproduction than can survive within the resources their environment provides. This
creates competition due to limited access to resources. Individuals within the species that have
variation in certain traits lead to an advantage over others for accessing these resources; this is
defined as “fitness”. It is important to keep in mind that the environment that the species lives in
decides on what traits are beneficial. Next the principle of inheritance comes into play, when
favorable traits are passed down to offspring’s of the next generation. This is what leads to
advantageous traits becoming more common in a population, and less favorable characteristics
become less common due to lack of survival. Eventually, over multiple generations of
inheritance, a new species will appear. This cycle of natural selection and inheritance of
beneficial traits is a crucial part in Darwin’s theory of evolution, and explains why some
members of the species survive over others without certain favorable traits.
One of the examples commonly associated with Darwin’s theory of natural selection has
to do with the evolution of color between moths in England during the nineteenth century. The
basics of the story involve the change in characteristics of the moths due to environmental
factors. Originally, pale colored moths where most common due to the trait of camouflage while
resting on light colored lichen-covered tree trunks. Due to new forms of pollution in the
nineteenth century like coal dust and fireplaces, the trees began to turn a dark gray, exposing the
pale moths to be eaten by birds. As birds switched from eating mainly dark moths, to mostly
eating pale moths, the common color of moths changed from pale to dark. This occurrence of
Natural selection resulted with the overall change in color of the British moth population.
So in conclusion, Charles Darwin’s theory of Natural Selection is based on the idea that
individuals within a species compete with each other for resources, and that individuals with
favorable traits are more likely to survive and reproduce more off springs. This repeated
inheritance of favorable traits over multiple generations eventually leads to favorable traits
becoming more common, and overtime can lead to the development of a new species. His theory
of natural selection can be generally broken down to 5 different assumptions, beginning with a
struggle for existence within a population. Second, variation in a population creates different
characteristics of individuals. Third, certain individuals have favorable traits, which increase
their ability to survive and reproduce. Fourth, inheritance of favorable traits are passed down to
the offspring’s of future generations. Finally, over a large period of time, variations in the
population eventually lead to the formation of a new species.
Work Cited
Darwin, Charles. Charles Darwin's Natural Selection: Being the Second Part of His Big Species
Book Written from 1856 to 1858. Paperback. Cambridge University Press, 1987. 27-28.
Print.
Guffey, Dr. Stan. "A Brief History of Charles Darwin."Darwin Day, Univ. TN Knoxville. n.d. n.
5-7. Print.
Houghton Mifflin Harcourt Publishing Company, Charles Darwin's Natural Selection. The
American Heritage® Science Dictionary, 2010. Print.
Klappenbach,, Laura. "An Introduction To Evolution." About.com Animals / Wildlife. Web. 28
Apr. 2013.