Chapter 15, Problem 34A

Summary Introduction

To analyze:

The reason genetic bottleneck can be an important evolutionary factor for a species.

Introduction:

Evolution can be defined as the change in the heritable characteristics of an organism in a species over many generations. Evolution is due to natural selection. The heritable characteristics that change are the characteristics that are passed on from one generation to another. The process of evolution has given rise to the biodiversity at every level of organization of biology or biological organization which includes the various levels of species, individual organisms and molecules.

Explanation of Solution

To a population, a bottleneck effect is a pretty profound impact. For a species, this bottleneck effect can be an important evolutionary event.

Bottleneck is an example of genetic drift. The bottleneck effect occurs when a population declines to a very low number and then rebounds. The rebound population has a gene pool that is very much similar genetically to the population at its lower level, meaning it has reduced diversity.

The bottleneck effect is when there is some initial population. Some individuals from that population survive. So, from a population of high genetic diversity, we go to a lower level where there isa very low number of individuals that survive. And those which do not survive are the ones which have low genetic diversity. If genetic diversity is more then the survival rate of an individual or an organism is more as it can withstand many conditions which a normal individual without any diversity cannot.

Conclusion

Therefore, the bottleneck effect prevents the species from reestablishing its former richness so that the new population evolving has a much-restricted gene pool which is much larger than the ancestor population.