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* Speciation * Michelle D. Grant * BIO/240
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Dr. Xavier Villarreal * Speciation
This paper will summarize three methods that could produce a new species to include Allopatric Speciation, Sympatric Speciation, and Polyploidy. It will provide specific examples of such to aid the understanding of this concept. It has been stated that humans have evolved from apes which would indicate a change in species had to have occurred at some point. It has also been stated that the finches that Charles Darwin found in the Galapagos Island were actually 14 different species. These concepts will give reasons that this may have happened.
What do the terms Species and Speciation Mean?
The term species is defined as, “a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. The species is the principal natural taxonomic unit, ranking below a genus and denoted by a Latin binomial, e.g., Homo sapiens,” ("", n.d.). Speciation is “the formation of new and distinct species in the course of evolution,” ("", n.d.). What is Allopatric speciation? Berkeley advises that Allopatric speciation, “is just a fancy name for speciation by geographic isolation... In this mode of speciation, something extrinsic to the organisms prevents two or more groups from mating with each other regularly, eventually causing that lineage to speciate. Isolation might occur because of great distance or a physical barrier, such as a desert or river,” ("Evolution 101 Allopatric Speciation: The Great Divide", n.d.). This basically means that an organism can be split away from its normal family by things such as water bodies or great icebergs. Once leaving the organisms normal family, it must adapt to this new area thereby gaining the possibility of changing it's traits. Once these traits change and the organisms procreate, they have created a new species. On example of such could include the Galapagos Finches that Darwin found on his journey. These birds were found in different areas of the world during this time and all had been seperated in some way such as geographically. Each of these birds developed different traits that would assist them in thriving such as differently shaped beaks and bodies. What is Sympatric speciation? The definition of Sympatric Speciation is, “A speciation in which new species evolve from a single ancestral species while inhabiting the same geographic region,” ("Sympatric Speciation",2010). While this can be seen more in plants, an example of such could be, “the rare sympatric speciation in animals, which is the divergence of resident and transient Orca in the northeast Pacific. These two groups of Orca occur in the same habitat but are avoiding each other and they do not interbreed. They have different diets, vocal behaviour, and social structures,” ("Sympatric Speciation", 2010). What is Polyploidy? “Polyploidy is the process of genome doubling that gives rise to organisms with multiple sets of chromosomes. The term ploidy (see glossary for this and other related terms) refers to the number of complete genomes contained in a single cell. In general, polyploid organisms contain a multiple or combination of the chromosome sets found in the same or a closely related diploid species. Polyploidy can arise from spontaneous somatic chromosome duplication, or as a result of non-disjunction of the homologous chromosomes during meiosis resulting in diploid gametes (for review see Ramsey and Schemske, 2002). It can also be artificially induced by treatment with drugs, such as colchicine, which inhibits cell division. Polyploidy can occur in all or most somatic cells of the organism or it can be restricted to a specific tissue. In the latter case the preferred term is endopolyploidy. Some examples of such specialized cells in animals include the salivary gland cells in Drosophila or liver cells in humans,” ("The Polyploidy Party", 2012). Hybrids fall into this category such as the grizzly bear/ polar bear mix called the Grolar now as they are identified. Another example could be the standard donkey. A donkey is created from a horse and a mule procreating. The result is a smaller horse looking creature with mule traits. The resulting donkey is also unable to procreate.
In Conclusion, This paper has summarized three methods that could produce a new species to include Allopatric Speciation, Sympatric Speciation, and Polyploidy. It has also provided specific examples of such to aid the understanding of this concept. Readers should now be able to see the possible reasons that speciation occurs in evolution.

References (n.d.). Retrieved from (n.d.). Retrieved from Evolution 101 Allopatric Speciation: The Great Divide. (n.d.). Retrieved from

Sympatric Speciation. (2010). Retrieved from

The Polyploidy Party. (2012). Retrieved from…...

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