Question

Draw a picture of a barrier to dispersal and how a species may change its appearance on either side of that barrier. Label the barrier as well as differences between the two organisms.

Answer 1

Ans.

I am trying to draw here topographic barrier.

Lake 1 (has crocodiles) Lake 2 No crocodiles BARRIER

Such barrier would obviously stop the crocodile species to come from one lake to the another. If we talk about barriers and the changes in the species. We must look at urban pigeon (Feral pigeon). It was seen that there existed only one type of pigeon (rock dove) earlier but after urbanization took place which provided barrier between the forests and now they also had to migrate to the urban areas and experienced many changes and were further called as urban pigeons. Thus, there existed the buildings as barrier between the urban pigeon and the forest pigeons.

I hope the example clear your doubt.

Due to barriers, there have come differences in both the species. Though both belong to one parent family, one makes houses in big buildings while other still live on the trees. Even their food pattern has also changed. Even in the example that I have drawn above, one lake, having crocodiles while other has fishes, cranes etc and thus there is a change in species due to presence of barrier.

I hope the answer is clear to you now, in case you have query further, please leave a comment, i will try my best to fix it for you. goodluck