Prep 19 Essay Example | Topics and Well Written Essays - 500 words

Prep 19 - Essay Example Speciation is the splitting of a lineage to produce two or more separate species. For this to happen, two or more of the members or species are selectively isolated and allowed to interbreed. When a species population extends over a wide geographical area and mating is selective rather than random, the gene pool is said to be sealed. This reduced gene flow causes the development of new species due to interbreeding. The importance of this is the generation of a pure species that repeatedly improve both genetically and phenotypically. Speciation involves the separation of an original species and the development of two or more pure species usually by a barrier. Allopatric speciation specifically involves the development of a physical barrier between separated members of the species to prevent crossbreeding. This results in geographical separation and hence interbreeding within the new geographical area. This is the dominant mode of speciation and once two separate populations are established the process of speciation continues. However speciation can result even without physical. This is known as sympatric speciation. In this type of speciation, a new species arises while living in the same location with the original species. This is believed to happen when a group of organisms from the species begins to occupy a distinct niche in the environment and eventually become adapted to the conditions while still breeding within themselves to produce a new species. Isolation of gene pool without geographical isolation happens when members of a species in the same geographical location occupy different niches in the same environment. In a similar way, social organisms have controlled mating and hence breeding only happens within the selected group. Species have developed mechanisms to control speciation and breeding. In reproductive isolation, the environment installs external