Allopatric speciation is a process of biological evolution that occurs when a population of a species is geographically isolated from the rest of its species and evolves into a new species over time. The term "allopatric" comes from the Greek words "allo" meaning "other" and "patris" meaning "homeland" or "country", and refers to the fact that the isolated population is living in a different geographic area than its parent population.

Geographical isolation causes allopatric speciation

Geographic isolation is the primary cause of allopatric speciation. When a population becomes geographically isolated from the rest of its species, it is no longer able to exchange genes with other populations. As a result, genetic differences begin to accumulate between the isolated population and its parent population. Over time, these genetic differences can become so great that the isolated population evolves into a new species.

Reproductive isolation is a consequence

Reproductive isolation is a consequence of allopatric speciation rather than a cause. As genetic differences accumulate between the isolated population and its parent population, the isolated population may become reproductively isolated from its parent population. This means that the isolated population is no longer able to interbreed with its parent population, even if the two populations are brought back together.

Interplay of geographical isolation and reproductive isolation

While geographical isolation is the primary cause of allopatric speciation, reproductive isolation can also play a role in the process. As genetic differences accumulate between the isolated population and its parent population, the isolated population may start to evolve reproductive barriers that prevent interbreeding with the parent population. These reproductive barriers can include differences in mating behavior, mating preferences, or physiological barriers to reproduction.

In conclusion, allopatric speciation is due to geographical isolation, which leads to genetic differences between the isolated population and its parent population. Reproductive isolation may also play a role in the process, as genetic differences accumulate and the isolated population evolves reproductive barriers that prevent interbreeding with its parent population.

Allopatric speciation occur due to geographic isolation where as sympatric soeciation occur due to reproductive isolation