Chapter 20, Problem 1P

Compare and contrast the terms in each of the following pairs:

a. population and gene pool

b. random mating and inbreeding

c. natural selection and genetic drift

d. a polymorphic trait and a polymorphic gene

e. founder effect and genetic bottleneck

Summary Introduction

To analyze:

To explain the similarities and differences between the terms in each of the following pairs:

population and gene pool random mating and inbreeding natural selection and genetic drift a polymorphic trait and a polymorphic gene founder effect and genetic bottleneck

Introduction:

Group of individuals which are able to inter breed is termed as population. In other hand gene pool is also part of population, but in this case instead of individual we consider collection of allele which are present in a population. Role of individual in a population is differential survival and deferential reproduction. In a population no one individual is considered a best fit, population have relatively fit individual. The relatively fit individual selected by natural selection but in case of genetic drift selection of individual is random processes or chance phenomenon. Genetic drift are also classified in to two groups according to their region of selection of a particular allele i.e. founder effect and bottleneck effect. Founder effect favors fixation of one allele due to the migration some individual, thus, small size population is formed. In this small size population inbreeding is takes place. On the other hand, if small size population is formed because of environmental forces (catastrophe), in bottleneck effect also responsible for fixation or loss of any allele in the population. Bottleneck and founder effect are collectively termed as a genetic drift.

Population having multiple allele contributes polymorphic phenotype or trait to the population and polymorphic genes responsible for these polymorphic traits. In a polymorphic population, allelic frequency is maintained by random matting. Inbreeding is exactly opposite to the random mating, which favors fixation of a particular allele.

Explanation of Solution

Group of individuals which are able to interbreed is termed as population. On the other hand, genes and alleles are groups in gene pool.

Population	Gene pool
In a population variation in alleles is less than gene pool.	In gene pool variation in allele is higher than population.
Frequency of allele is constant.	Due to inbreeding formation of gene pool.
Mostly it having interbreeding organism.	Gene pool is termed as genetic variation found in population.
Population carrying the part of gene pool in genome.	It provide genetic information which is inherited in next generation.

Random mating has no selection criteria for mating partner. In other hand inbreeding is the mating in related individual that have greater similarity in alleles.

Random mating	Inbreeding
Mating partner not selected.	Matting occur in between related organism.
Frequency of intermediate or heterozygote population is decrease.	Due to inbreeding frequency of homozygous increase in a population.
There is no limitation.	It’s having selection criteria, in case of plant have self-fertilization.
Two phenotypes of random mating are positive and negative assertive mating.	Mostly affectsexually reproducing organism, which has similarity.

Natural selection is an evolutionary process which mostly selects the relatively fit individual. In the genetic drift chance of fixation of particular allele.

Natural selection.	Genetic drift.
It supports the reproductive success of certain member.	It mostly affect the small population
In this case no selection criteria.	Present generation genes and alleles are different than previous generation.
It is measured in relative finesses of individual.	It has straight effect on population.
It has no or very less effect on allelic frequency.	It causes major change in allelic frequency.

When multiple alleles are present on one locus it is termed as polymorphic gene. Different phenotype present in same population is termed as polymorphic trait.

Polymorphic trait	Polymorphic gene.
It is measured Quantitatively.	Multiple genes involved in the one phenotype.
Polymorphic traits has small mutation step.	It is used to explain different form of single gene.
Large population is polymorphic.	In the population, one locus presents multiple allele.
Height and skin color is the example of polymorphic trait.	These genes are studied in human genome project.

Formation and establishment of new small size population through migrations known as founder effect. The phenomenon which generates the large allele frequency error in small population is term as bottleneck.

Genetic bottleneck.	Founder effect.
Formation of small size population because of environment.	Formation of small size population because of migration.
It carries completely different allelic frequency.	Is straightly depends on the size of colonizing group.
Chance of fixation of any allele in a population.	Chance of fixation diseased allele in population.

Conclusion

The similarities and differences between the given terms are explained above.