Although Darwin and Mayr both contributed enormously to the topic of speciation, they had two totally different views on the main mechanism driving it. Darwin noticed geographic isolation but discounted any importance in it believing natural selection to be the driving force, while Mayr believed that geographic isolation was the driving force of speciation and founded the theory of allopatric speciation. For decades Mayr's idea has been the traditional method thought to result in the highest amount of speciation, but recent support has shifted from allopatry and Darwins gradualism to rapid and sporadic periods of speciation with periods of relative equilibrium regardless of geographic barriers.
Darwin, the father of evolution was amazingly correct or close to the truth on most of his theories regardless of modern day proofs such as genetics. Darwin first noticed a pattern of speciation on the Galapagos islands when the vice-governor, Mr Lawson, told him that he could tell what island each of the tortoises were from simply by looking at them. Darwin found this unbelievable, until his own observations confirmed Mr. Lawson's claim (Schilthuizen 2001). Darwin believed that natural selection was the driving force behind speciation. "The passage from one stage of difference to another and higher stage may be, in some cases, due merely to the long-continued action of different physical conditions in two different regions; but I have not much faith in this view, and I attribute the passage of a variety, form a state in which it differs very slightly form its parent to one in which it differs more, to the action of natural selection." (Darwin 1859).
In order for natural selection to occur there needed to be large populati...
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...n University Press, 1977.
Freeman, S. and Herron, J. Evolutionary Analysis, Third Edition. Upper Saddle River, NJ: Pearson Prentice Hall, 2004.
Hosken, D. Martin, O. 2003. The evolution of reproductive isolation through sexual conflict. Nature 423: 979-982.
Mayr, Ernst. Populations, Species, and Evolution: An Abridgment of Animal Species and Evolution. Cambridge, Massachusetts: The Belknap Press of Harvard University Press, 1970.
Patterson, Colin. Evolution, Second Edition. Ithaca, NY: Cornell University Press, 1999.
Ridley, M. 2002. A popular evolution. Nature 417: 223-224.
Schilthuizen, Menno. frogs flies & dandelions. Oxford New York: Oxford University Press, 2001.
Tautz D. 2003. Evolutionary biology: Splitting in Space. Nature 421, 225-226.
Winker, K. 2000. Evolution: Migration and speciation. Nature 404: 36.
1) Carroll, R. L. 1988. Vertebrate Paleontology and Evolution. W. H. Freeman and Company, New York.
Reznick, D. N. & Ricklefs, R. E., 2009. Darwin’s bridge between microevolution and macroevolution. Nature, Volume 457, pp. 837-842.
Darwin: A Norton Critical Edition, Second Edition ; ed. by Philip Appleman; copyright 1979, 1970 by W.W. Norton & Company, Inc.
...re key factors in the high rate of speciation. These conclusions are derived from the lack of correlation of phenotypic evolution with distance and differences in habitat. Instead, random individual dispersal creates frequent genetic bottlenecks. The observation that phenotypic variability decreases with increasing cave age challenges the traditional founder-effect concept, which claims that genetic variability increases with a growing population. The observation is more consistent with the founder-flush concept. However, the data has led to new questions regarding the factors that play into evolution, specifically the reaction between population density and stochastic events. Further investigation of the role that frequently replicating small founder populations plays in the generation of new species will increase knowledge of the complicated process of speciation.
In Mivart’s Genesis of Species, the author highlights the inconsistencies of Darwin’s natural selection theory. He supports his assertion by emphasizing how species placed in similar environments acquire different traits, questioning the long-term advantages of these evolved traits, and noting the logical inconsistencies of how traits can span in all directions.
Bowler, Peter J. Evolution: The History of an Idea. London: University of California Press, 1989.
In Charles Darwin’s life he had helped make a significant advancement in the way mankind viewed the world. With his observations, he played a part in shifting the model of evolution into his peers’ minds. Darwin’s theory on natural selection impacted the areas of science and religion because it questioned and challenged the Bible; and anything that challenged the Bible in Darwin’s era was sure to create contention with the church. Members of the Church took offense to Darwin’s Origins of Species because it unswervingly contradicted the teachings of the book of Genesis in the Bible. (Zhao, 2009) Natural selection changed the way people thought. Where the Bible teaches that “all organisms have been in an unchanging state since the great flood, and that everything twas molded in God’s will.” (Zhao, 2009) Darwin’s geological journey to the Galapagos Islands is where he was first able to get the observations he needed to prove how various species change over t...
Evolution became extremely popular since the publication of Charles Darwin’s theory in his infamous book, The Origin of Species: By Means of Natural Selection or The Preservation of...
Whether it be at a high-end banquet or at a BBQ in the park, when conversing with a group of people it is often said to “never discuss religion and politics.” These are two topics that one is advised to stray away from when socializing with others due to the fact that some may have their heart and soul invested into the matter, thus revealing your opinions on “what is going to happen after we die” or “what political party is better” may lead to offensive comments and a chaotic argument. The caution of approaching these topics in conversation should also be the same when discussing evolution. When talking about evolution or sharing an opinion, one must tread lightly as one maybe stepping on a couple of toes with their opinions. The topic of evolution branches out into numerous theories and hypotheses that may be simple to a creationist or a biological scientist but to a person such as myself, evolution can be a labyrinth. Due to the numerous and perplex theories of evolution, my goal is to shine light and provide understanding for a single topic in relation to evolution. By no means is this factor more important than the others as mutation and genetic drift demonstrate an equal importance to evolution, however a vast ocean of biological information can not be explained by one student. The main focus of this paper is on a factor that is present in animal kingdoms all o...
Raven, Peter H., George B. Johnson, Kenneth A. Mason, Jonathan B. Losos, and Susan R. Singer. "Quantifying Natural Selection." Biology. Tenth Ed. New York: McGraw-Hill Companies, 2013. Print. 8 Apr. 2014.
Anyone with even a moderate background in science has heard of Charles Darwin and his theory of evolution. Since the publishing of his book On the Origin of Species by Means of Natural Selection in 1859, Darwin’s ideas have been debated by everyone from scientists to theologians to ordinary lay-people. Today, though there is still severe opposition, evolution is regarded as fact by most of the scientific community and Darwin’s book remains one of the most influential ever written.
Darwin’s observations from the islands made him want to come up with some explanation to why this occurred. He began to do research of each the species that had lived on these islands and observe all of the characteristics that had. He noticed that the islands h...
The theory of natural selection is not limited to inheritable and beneficial variations of a species. It also relies a great deal on the population growth and death of a species. For a species to continue to exist it must make sure of a few things. It must first produce more offspring that survive. If this is not done then the species is obviously going to die off. It is also important for the species to propagate at such a rate as to allow for variance, for it is variance that will ultimately allow the animal to exist comfortably in his surroundings. In his studies, Darwin was led to understand that “…the species of the larger genera in each country would oftener present varieties, than the species of the smaller genera;” (p. 55). Thus the larger species would adapt while the smaller one would not. And to quote Darwin again, “…if any one species does not become modified and improved in a corresponding degree with its competitors, it will soon be exterminated.” (p. 102)
Gould, Stephen Jay. "Evolution as Fact and Theory." The Norton Mix. Editor Katie Hannah. New York: W.W. Norton & Company, 2010. 110-119.
On Darwin’s trip around the world he found something very interesting on the Galapagos Islands. On the isolated islands he found fourteen species of finches with very similar characteristics but they had some differences in their beaks, diet, body size and habitat. Darwin thought the birds had a common ancestor. He thought that some time back some finches arrived on the islands and the finches with the beaks that suited the islands conditions survived this happened on all the islands. When they had offspring the next generation would inherit the same beak. This is a great example of natural selection which was a contributor to how humans evolved. From this Darwin established his theory of natural selection and how slowly over time creatures...