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Genetic Drift: Complete Explanation

Genetic Drift

INTRODUCTION TO GENETIC DRIFT

The term genetic drift is also called by the name of Sewall Wright effect or Allelic effect. In this regard, it can be said that genetic drift is being regarded as the process in which deviation in the expected allele frequencies tends to develop in the finite population over the period of time. In simple words, it can also be said that genetic drift is the type of variation that occurs in the existing gene variant in the population because of the presence of random sampling organism. This can be further explained with the different types of examples. For instance, a mother who is having blue eyes and a father who is having brown eyes can have a child with either blue or brown eyes. In this situation, if brown eyes are the dominant allele, even in the condition that there is a 50% chance that a child could have blue eyes then in this situation also there might chances that a child could have brown eyes. It is called genetic drift.    

Herein, it can also be said that the population’s allele frequency is basically the fraction of the copies of the one gene that allocates a particular form. Here, we will basically explore the causes behind the genetic drift. Further, we will also carry on discussion upon the two major effects that are related to the genetic drift in an effectual manner. The details will also be given about the differences that exist between genetic drift and mutation. Now our experts from My Assignment Help will tell you about the features of Genetic Drift.

FEATURES OF GENETIC DRIFT

Before getting into more details about the genetic drift, it is important for the individual that it should have a better understanding of the major features that are related to the genetic drift. The details about the same are depicted below:

  • The loss in relation to the genetic variation results within the population itself.
  • Additionally, it also has a feature that the divergence that is related to the genetics results between the populations in an effectual way.
  • The allele frequency in the genetic drift changes until the H will become zero.

Thus, it can be said that with the use of these given features it will become very easy to recognize the occurrence of genetic drift among the population in an effectual manner.  

WHY GENETIC DRIFT IS IMPORTANT?

After getting an idea about the features that are associated with the genetic drift, it is very much important that an individual should be an idea about the importance of genetic drift in evolution. However, if no significant knowledge in relation to the same is being gained then in this situation it will become very difficult for the people with respect to get the proper idea about the particular term. The details about the same are given below:

  • In the process of evolution, genetic variation is being considered as one of the most important element. This is because; it enables the natural selection in relation to the increase and decrease the frequency of alleles that is already present in the population.
  • Additionally, it also gives an opportunity to individuals with regard to adapt themselves as per the environment. However, along with the given task, it also assures the survival of the population. Thus, from the given thing it is very much important that genetic drift should occur in a population. But, in case if it does not occur then in this situation it will be regarded as one of the biggest matter of concern for the survival of the population.  

WHETHER GENETIC DRIFT OFFERS SURVIVAL ADVANTAGE?

On reviewing different studies, it has been examined that genetic drift is basically random alteration that tends to occur in the gene of population. However, this alteration might result due to the evolution of the new population that is genetically different from the old population. It is due to the presence of a given aspect only genetic drift offers survival advantage because it allows the population to cope with the new environment.

Consequently, some studies state that genetic drift does not offer a survival advantage. This is because it suddenly causes changes in the gene of a small population. This is due to some accidents. Now our assignment experts will tell you about the causes behind the genetic drift.

CAUSES BEHIND THE GENETIC DRIFT

Till now, we have gathered very much knowledge about the genetic drift in a general way. But, now it is very important to know why genetic drift occurs. Thus, in the respective section detail explanation will be given about the causes that lead to the situation like genetic drift in an efficient way. 

Matting pattern leads to the genetic drift

It is being considered as the very first reason behind the occurrence of a situation like genetic drift. Herein, it can be depicted that nonrandom type of mating tends to occur when an organism chooses to mate with others on the basis of the specific type of traits. Hence, in the given type of circumstances, an individual will make the varied type of behavioural choices. The given type of choices will give shapes to the genetic combinations and thus they appear in the successive generations. If the given type of things happens then in this condition the population pattern of matting will no longer be considered as the random.

There are two forms of the nonrandom mating and these are inbreeding and outbreeding. In accordance with the given context, it can be said that inbreeding is the type of breeding in which two people who have similar genes mate with each other. Consequently, outbreeding is the form of mating in which two individuals who belong to the varied genotypes will mate with each other. From the given thing, it is very correct to say that inbreeding will lead to reducing genetic variation or the genetic drift. But, in comparison to this high number of generic variation is being seen in the condition like outbreeding.   

Random forces that lead to genetic drift

It is also being regarded as another big cause behind the occurrence of a situation like genetic drift in an effectual manner. Therefore, it can be said that sometimes there are many random fluctuations tends to occur in the number of alleles in the population. The charges incurred in the relative allele are called by the name of genetic drift. However, the genetic drift can be an increase or decrease over the period of time in an effectual way. Mostly, the genetic drift occurs in the small population. This happens because in the small population there are greater chances of being lost. But, in comparison to this in a large population, there are very fewer chances of being lost.   

Moreover, the situation like genetic drift will remain until the allele which is being involved in the population is completely lost or it is fully involved with the present population. In both the given condition, there are very fewer chances of the occurrence of a condition like genetic diversity in the population in an effectual manner. On the other hand, genetic drift is very much common after when the population will experience the situation like population bottleneck.

The distribution also leads to the genetic drift  

This involves the physical distribution of the people which also has a significant impact on the population. In this context, it can be depicted that a species which has a very broad distribution rarely have the same genetic makeup over the whole range. For example, some population lives at a higher altitude and some live at the lower altitude. The allele in population in both the given situation will differ dramatically. Thus, in simple words, it can be said that distribution is being considered as one of a way with the help of which genetic variation in the population can be preserved in the larger population. This will happen over the wide physical range. Additionally, if an individual at any of the given range such as high and low altitude will reconnect and starts mating then in this situation the given thing will result in genetic intermixing. This will contribute to the more of variation in the genetic in an effectual way. Overall, it is very right to say that genetic drift is also the result of the manner in which the whole population is distributed.    

Migration also leads to genetic drift

It can be called as the last cause that will lead to the condition like genetic drift in an effectual way. Migration is being defined as the movement of the individual (organism) from one place to another. However, the given thing can also occur in the cyclical pattern. In this regard, it can be said that if an individual that is migrating from one place to another forms a relationship with the destination individual, then the given type of condition will lead to providing the sudden influx of alleles. Here, when the migrated individual will mate with the destination individual then in this situation then the migrated individual will leads to carry the alleles of a specific individual who belongs to the destination place. Thus, due to the given situation, there is a significant change can be seen in the alleles of the population where the migrated individual stays. Overall, it is very correct to say that these all are being regarded as some of the major causes which lead to the genetic drift. The proper care should be assured in relation to the same with an aim to maintain proper balance in relation to alleles in population in an effectual manner.

BOTTLENECK EFFECT

We have discussed many things about the genetic drift, but there are two major effects that are related to the same and for the individual, it is very much essential that some knowledge should also be gained in relation to the same.

Herein, it can be said that genetic bottleneck is basically the type of evolutionary event in which the size of the population drastically reduces from the large to the small. The main reason behind the same is the presence of environmental factors such as floods, earthquakes, fires, and droughts, etc. The given type of factors will tend to cause a reduction in the genetic diversity of the population in comparison to the parent population. On the other hand, the given type of circumstances will also lead to some alleles to overexpressed in survival population. However, some alleles are underexpressed in the survival population. Additional, as per the direct aftermath of genetic drift, homogeneity and inbreeding will be increased in these populations. Thus, the given thing will lead to giving rise to the occurrence of the deleterious mutation in an effectual way. For instance, it can be said that the diversification of the hyperthermophilic pyrococcus and the antigenic shift is the result of natural selection and the genetic drift. However, the genetic bottleneck can be effectively explained with the below-given diagram.

genetic bottleneck
genetic bottleneck

The very first bottle entails about the original population which possesses different types of colours. However, in the situation, of a genetic bottleneck, the original size of the population will decline and the given thing will completely change the gene of the new population. Thus, from this, it is very right to say that genetic diversity is the result of the different environmental factors upon which an individual will not have any control.   

FOUNDER EFFECT

After bottleneck, the founder is also being regarded as another main effect that is related to the genetic drift. In accordance with the given context, it can be depicted that founder effect tends to occur when few members take the decision to start the new colony. The members who take this decision will belong to the original population. Thus, the given population will be very small in nature.  On the other hand, the given population may possess the following features such as reduce genetic variation in comparison to the original population. Further, the nonrandom sample of the genes is also being regarded as another significant feature of the small population.

Additionally, the given effect was basically outlined by the Ernst Mayr in the year 1942. Here, it has basically used the existing theoretical work which was being developed by Sewall Wright. In addition to this, it can also be depicted that due to the loss of the genetic variation, the new population that has evolved will be distinctively different from the parent population in both phenotypically and genotypically manner. However, in extreme cases, the founder effect will also lead to the subsequent evolution of the new species and speciation.

But, the given thing can also be effectively explained with the help of the below-given diagram.

As you can see, there are four major circles. The very first circle is the whole population. It is also called by the name of the original population which possesses an equal number of blue and red dots. But, in the founder effect, the new population will be regarded as very small in nature. Thus, it is the reason why it tends to shows increased sensitivity to the genetic drift. Hence, it is another main effect that is associated with the genetic drift in an effectual manner.   

DIFFERENCE BETWEEN GENETIC DRIFT AND MUTATION

There is a significant difference tends to exist between genetic drift and the term such as mutation. But, the given things can be effectively explained in the below table:

GENETIC DRIFT MUTATION
It basically accounts to the random changes in the allergic frequency by the chance. In simple words, it can also be said that it is being regarded as the chance of eliminating some alleles and performing the fixation of some alleles.   It is the form of genetic material that leads to the phenotype and genotype of the organism. It is being caused by the varied types of factors and they are called by the name of mutagens.
Environmental factors, migration, and nonrandom factors are being considered as the main causes behind the genetic drift.   Radioactive material change and the X-ray are being regarded as two main causes that will lead to the result like mutation.
This will occur in the small population and it also provides diversity without any kind of adaptation. It includes different physical and chemical factors which lead to cause changes in the gene of the population.

CONCLUSION

From the conducted analysis, it can be said that for the individual it is very much important that it should have a good understanding of the genetic drift.  This is due to the reason that it is by having a good knowledge of the same only a person is able to get the idea about the changes that are occurring in the population. Further, it is also important that an individual should also have information about the bottleneck and founder effect that is related to the concept of genetic drift.  The given thing will give the opportunity to a person to get a better idea about alleles in a population. For more information, you can also check with Assignment Help Online.

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