Describe a possible opposing interaction between 2 of the 4 mechanisms of evolut
ID: 178941 • Letter: D
Question
Describe a possible opposing interaction between 2 of the 4 mechanisms of evolution acting on a single population and provide a real or hypothetical example to support your answer. Include how each mechanism would affect the genetic diversity of that single population. Describe a possible opposing interaction between 2 of the 4 mechanisms of evolution acting on a single population and provide a real or hypothetical example to support your answer. Include how each mechanism would affect the genetic diversity of that single population. Describe a possible opposing interaction between 2 of the 4 mechanisms of evolution acting on a single population and provide a real or hypothetical example to support your answer. Include how each mechanism would affect the genetic diversity of that single population.Explanation / Answer
Answer:
The possible opposing interaction between two of the four mechanisms of evolution acting on a single population:
The opposing interaction of evolutionary mechanism hypothetically between the natural selection and genetic drift because natural selection is going to predominate in "large population" (increasing genetic variability due to appearance of more gene variants) as evolutionary mechanism whereas genetic drift is going to predominate in "small population" (decreasing genetic variability due to disappearance of gene variants).
There are total four mechanisms of evolution
Mutation
Natural selection
Genetic drift
Recombination and gene flow
Natural selection: The opposing interaction is between the natural selection and genetic drift action of African population with sickle anemia allele in carrying genome insensitive to combat malaria infection. The genetic diversity of the African population has increased due to balanced polymorphism with single nucleotide polymorphism followed by natural selection of advantageous traits
Natural selection & mutation:
Codominance expressed by heterozygous alleles of African population in which one is normal and another is mutant form that coexist, thereby the heterozygous for sickle cell allele result in both normal (HA) and abnormal (HS) hemoglobin in the circulating blood.
The inheritance of recessive genes (disease causing) can remain prevalent if presence of two copies of an allele is disadvantageous and presence of one copy of the allele may be advantageous.
For example in case of sickle cell anaemia, two alleles may cause sickle cell anaemia but carrying one allele is advantageous in regions where malaria is common because this single copy of allele offers resistance against malaria (common in African human phenotypes irrespective of colour). Thus, many people still carry the allele of sickle cell anaemia, as natural selection does not remove it; this called “balanced polymorphism.”
Another example of genetic drift:
A considerable change in the allelic frequency due to change in selection coefficient & genetic drift of the predominantly produced from the sampling effects if there are a very low population number obtained from a considerably big population primarily and forming colonies in a new area result in a new population due to founder effect. For example, therefore, a small population from Britain migrated to a small island between South America and Africa during the early 1800's, establishing a new population result in inbreeding of the population already existing there to generate genetic variation genotypically & phenotypically different from the allele frequencies from the original population of Britain.
Founder effect can be due to decrease in genetic diversity of an individual population; for example Pennsylvania Amish population in which higher frequency of genetic disease due to recessive gene carrier by both the couple.