Question

a) In the context of the extinction vortex, describe and explain, using the examples of your choice, at least three spirals that make small populations increasingly vulnerable to extinction. Your answer should include at least TWO mechanisms of evolution other than natural selection that play a role.

b) We have also seen examples of populations that have recovered after a population bottleneck. What factors might influence how likely different organisms are able to successfully do this? Describe what factors are likely to influence their persistence.

Answer 1

a)

Possible three  spirals that make small populations increasingly vulnerable to extinction are:

1. Genetic drift: This can lead to extinction by rapidly decreasing the essential biodiversity of the population due to changes in the genetic level.

2. A sudden decline or loss in the population size due to environmental stresses like disasters,deadly diseases or through various interactions like predation.

3.Gene flow: When there is restricted the diversity is reduced leading to isolation and further may result in extiction.

Of the above 1 and 2 are other mechanisms of evolution.

b)

Recovery after a population bottle neck may be achieved by certain factors which mainly includes increase in the intrainsic reproduction and immigration.The factors like respinse to a stressful condition which may lead to population bottleneck will result in finding more adaptable regions and for survival