Darwin's 4 Postulates
Information Darwin Swore By
"The power of Selection, whether exercised by man or brought into play under nature through the struggle for existence and the consequent survival of the fittest, absolutely depends on the variability of organic beings. Without variability, nothing can be effected; slight individual differences, however, suffice for the work, and are probably the chief or sole means in the production of new species." Charles Darwin (1868)
Postulate No.1 - Variation
According to Darwin, variation in species is greatly influenced by internal and external environmental factors that the species might find itself in. Though similar genetic information might be present in the different species, the focus of species variation lies greatly in the phenotypical aspect of species.
Postulate No.2 - Inheritance
Inheritance is a key postulate in Charles Darwin's theory because it encompasses the idea of sexual reproduction of species in order to produce an offspring with the strongest of characteristics, thus favouring the offspring for the long race that is survival of the fittest.
Postulate No.3 - Differential Survival
According to Darwin and this postulate of differential survival, it is the fittest species that is bound to survive the hardships, thus eliminating the weaker kind and assuring an environment for the strongest.
Postulate No.4 - Extinctions
First and foremost, Darwin truly believed that the rate at which species became extinct was much slower than the rate at which the population of these species had surged. He suggested that there was no such thing as "Mass Extinctions", an idea pitched in by many scientists of the time which encompasses the idea of a sudden disappearance of species, but it was rather a misreading on the gap of information.
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http://www.genetics.org/content/183/3/757
Gaylord, G (2006, December 8). Charles Darwin on Extinction. Biology Online. Retrieved April 6, 2016
http://www.biology-online.org/articles/role_extinction_evolution/charles_darwin_extinction.html
Harrison, R. M. (2006, January). Variation, Within Species: Introduction. Wiley Online Library. Retrieved April 6, 2016.
http://www.els.net/WileyCDA/ElsArticle/refId-a0001704.html
Terrazas, T. (2013, December 3). Differential Survival and Growth. PubMed.Org Retrieved April 6, 2016,
http://revisionworld.com/gcse-revision/biology/genetics-and-dna/variation-mutation