Question

How would you compare and contrast the founder effect and the bottleneck effect?

Answer 1

The population bottleneck effect is related to ecological phenomenon decreasing a population to a tiny handful and leaving tiny variations in the surviving individuals while the founder effect takes place when new colonies of tiny size and reduced genetic diversity are formed.

Complete answer:
-Genetic drift is an evolutionary change in allelic frequencies of a population as a matter of chance. It takes place in tiny populations but its effects are strong. Genetic drift usually occurs in smaller populations. In a tiny population with several alleles any of the alleles can be lost. In a population with many organisms, there is less chance of losing an entire allele as organisms have different alleles and all the alleles could not shed off.
-Founder effect and the bottleneck effect are the two types of genetic drift which result for tiny populations having subsets of genetic diversity of the same population. The effects are the same for both but the founder effect makes the parent population enclosed.
-Bottleneck effect: The population size is less because of predators or diseases.
-The frequency of certain alleles in a population changes because the organisms that carry them are eliminated. The increase in number because they are the only alleles left.
-Although organisms do not move from place to place, the size of their populations may sometimes be drastically reduced which leads to flooding, drought or other environmental problems. A discrete genetic sample of the same population contains some surviving individuals. The resulting modifications and loss of genetic diversity are known as bottleneck effects.
-Founder effect: Occasionally one or few people separate and become at some distance from their place of origin, the founder of a new, isolated population. All the alleles existing in the source population are not likely to be present in their pioneers. Thus some alleles from the new population may be lost and others may change in frequency drastically called founder effect.
-In this new population is founded in a new location due to physical or geographical barriers. The new population does not have any contact and mate with the normal population.
-There are different species which are seen on a specific island. Example: two birds belonging to the new species reach an island. Their alleles will help in the diversity on that particular island. These alleles will dominate and mutations in the populations will lead to formation of new species. The upcoming population will diverge so much that there will be no interbreed among them.

Note: Genetic drift does not depend on the beneficial or harmful effects of an allele. Drift changes allele frequencies purely by chance as random subsets of individuals have been collected to develop the next generation. Cases in which a small population is formed from a larger population are the founder effect and bottleneck effect.