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| 1. |
How geographical isolation help in evolution? |
| Answer» Geographical isolation is the isolation of population by physical barriers such as stretches of water or mountain ranges.There is a population of red beetles living in a mountain area covered with green bushes. Various sub-population in the large-population exists in the neighbourhood. Individuals of a sub-population reproduce sexually among themselves and numerous variations accumulate in these sub-populations of red beetles.There may be some reproduction among these sub-populations. If a beetle from one sub-population strays into other’s area and some individuals from one sub-population may be carried by predators to the area of other sub-population, then random reproduction takes place. It may lead to migration of genes from one sub-population to other.If the sub-populations are isolated due to the presence of river between them:(i) Variation will accumulate in isolated sub-population.(ii) Over a period of generation, the sub-populations would get very different from each other due to the processes of genetic drift and natural selection and they will not be able to reproduce themselves. | |