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Natural Selection
Natural Selection
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As defined by the Encyclopedia Britannica, Natural selectionis a process that results in the adaptation of an organism to its environment by means of selectively reproducing changes in its genotype, or genetic constitution.
In 1835, Throughout a five year journey to the galapagos islands in the Pacific Ocean off the coast of South America to study animals, plants and fossils, english naturalist Charles Darwin developed the idea of natural selection. Which was shared more openly later on in his book, “On the Origin of Species by Means of Natural Selection” publishedin 1859.
Natural selection is the process by which living organisms adapt and change to best suit the environment that is home to them. Over multiple generations, random variations that occur in the genotype of a living organism that allow it to thrive inits environment, increase its chances of survival and reproduction are preserved and passed down to future generations. Over multiple generations, these positive variations in the genotype of living organisms grow to be found more commonly throughout their populations. On the other hand, the organisms that have been born with less beneficiary variations of their genotype often die or don't last verylong. Natural selection can occur in the variations of survival, fertility, development rate and other aspects of life for an organism. In undisturbed environments, the gene frequencies of living organisms tend to remain somewhat constant, since there is no reason in an environment for it's organisms to adapt. There are a couple factors that can affect the gene frequencies of living organisms such as mutation, migration, random genetic variations and natural selection. These factors all alter gene frequencies regardless of the effects, whether it is beneficial or not to the survival of that organism in its environment.
Artificial Selection
Charles Dawin came up with the name natural selection as an opposite of artificial selection which is not controlled by nature and by the species itself. Darwin gave an example of a popular hobby in his time, pigeon breeding, where people choose the better looking and flying birds and breed them with each other to pass on those good genetics to future offspring. To prove his theory he argued with other scientists in his time about the process of artificial selection, trying to prove the point that there is no process like artificial selection that happens in nature, where the nicest looking and flying birds for example are the ones that reproduce more. What does happen in nature is a similar process to artificial selection only that the organisms that are breeding are the organisms with better genetics that allow them to survive in their environment instead of their visual characteristics.
In his time, Darwin was unaware of the concept of genes but he did pointout that many traits from parents are passed on to their offspring. Darwin also explained that natural selection is how animals from one common ancestor can drift so far apart over
generations to best fit their environment.
Organisms do adapt to their environment over multiple generations but when they can not adapt at the same speed at which their environment is changing, that species often goes extinct. Some of the factors that could lead to extinction of a population include an invasive species, a disease organism, a sudden environmental change, or a highly successful predator. There are a few newer cause of extinctions caused by our modern day actions such as overhunting a species and destroying their habitat for expansion of civilization
May 28,2020. Eric Drivdal
National Geographic Society. “Natural Selection.” National Geographic Society, 7 Sept. 2019, www.nationalgeographic.org/encyclopedia/natural-selection/.
The Editors of Encyclopaedia Britannica. “Natural Selection.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 3 Feb. 2020, www.britannica.com/science/natural-selection.
Gildenhuys, Peter. “Natural Selection.” Stanford Encyclopedia of Philosophy, Stanford University, 25 Sept. 2019, plato.stanford.edu/entries/natural-selection/.
