Summarize key differences between allopatric and sympatric s

Summarize key differences between allopatric and sympatric speciation. Which type of speciation is more common and why? Describe two mechanisms that can decrease gene flow in sympatric populations, thereby making sympatric speciation more likely to occur. Is allopatric speciation more likely to occur on an island close to a mainland or on a more isolated island of the same size? Explain your prediction.

Solution

Allopatric speciation occurs when the population of a species separate apart due to a physical barrier like river and mountain etc. The two separated groups of same population get isolated from each other and under the influence of natural selection and other factors, slowly they develop into a new species. Sympatric speciation occurs in the same population without any physical barrier and without any geographical separation. When a particular species cannot interbreed, it becomes reproductively isolated. It is mainly found in plants. Allopatric speciation is common because in nature many types of changes keep on happening due to which species generally get separated from their own groups, geographically. Their geographical separation may take them to new species of a completely new population, where they reproduce and produce a new form of life. (a)Polyploidy: where the organisms achieve an extra set of chromosome due to accidental process during cell division. The two species may also interbreed and produce a polyploid species. (b)Habitat Isolation: where the two species may live in and get adapted to different habitats, having no interaction with each other even when they are not separated by any physical barrier. both of these processes reduces the gene floe in sympatric speciation. Allopatric speciation is more likely to occur on the island that is more isolated. Because in that case, the population of mainland will be completely separated by the population of island.