Two sister species of insects feed on different parts of the
same plant species, one on the stem and the other on the leaves. Hybrids between the insect species grow more slowly and have reduced survival, indicating some form of postzygotic barrier. Outline conceptually what you would need to show to infer that ecological speciation is the mechanism generating this reproductive barrier, and briefly
describe how you might test this.
Due to the Divergent evolution , these species of insect change their feeding pattern (one accepting feed on stem and one feed on leaves ) . Due to this changing feeding pattern competition between Two sister species is reducing by this partition feeding on plant .
On course of evolution various changes will develop into this insect . They develop various barrier to seprate each other from many aspect.like - feeding , nature , reproduction .
But if hybrid between these two sister species of insect - they show post zygotic barriers :- as follows;
Postzygotic barriers play an important role in speciation . But their role may be reversed to final stage of speciation .
Major contribution of post zygotic barrier to role speciation as following :-
1- reduction of gene flow : Postzygotic barriers can effectively reduce gene exchange between two parental species into their hybrid .
2-early onset of species boundaries via rapid evolution : postzygotic barriers can evolve between recently diverged populations or incipient species, thereby influencing speciation relatively early in the process.incompatibilities may also serve as important barriers early on in speciation.
3-reinforcement : intrinsic postzygotic barriers can promote the evolution of subsequent reproductive isolation through processes such as reinforcement, even between relatively recently diverged species pairs.
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