Speciation & Its Types MCQ - Practice Questions with Answers

• Speciation refers to the formation of two or more species from an existing species.
• The populations of a species present in different environments and are separated by geographical and physiological barriers, accumulate different genetic differences due to different mechanisms of evolution.
• These populations then become different from each other morphologically and genetically, become reproductively isolated and evolve into new species.

Allopatric Speciation:

• Allopatric speciation involves geographic barriers, which physically isolate populations. 
• The formation of a land bridge and the emergence of a mountain range could separate members of a lowland species. 
• Movements of animals and plants can also result in physical isolation. Single individuals or small groups of individuals may move away from a parent population to colonize a new area, and the new colony could be isolated from its parent population.
• Nonetheless, geographic barriers (the land bridge, the ocean) isolate the two populations so that gene flow stops and genetic divergence can proceed. 
• Natural selection may lead each population to adapt to its own unique environment, or genetic drift may lead to chance differences in gene pools. 
• If genetic divergence results in reproductive incompatibility, the two populations have become two separate species.

Sympatric Speciation:

• Sympatric speciation involves the emergence of a new species within the geographic range of the parent population. 
• In the absence of geographic isolation, reproductive barriers must arise in different ways in order for new species to form.

Parapatric Speciation:

• It takes place when a population of a species enters a new niche or habitat.
• It occurs only at the edges of the parent population.
• Although there is no physical barrier between these populations, yet the occupancy of a new niche resulted in a barrier to gene flow between the populations.