Explain the difference between the concept of the traditional use of the word “genetic mutation” and the more contemporary term “genetic variant”. Explain the concepts of 1) harmful mutations and purifying selection, 2) of neutral mutations and 3) variants that are retained via positive (or Darwinian) selection. Explain how a positive variant may influence local alleles (on the same chromosome very close to the new positive variant) by selective sweep of hitchhiker alleles.
genetic mutation - this is a permanent alteration in the DNA sequence that contains a gene. Mutations affect chromosomes and genes.
Genetic variations, or variants- this is the difference that provides unique characteristics to the genome of each person.
1. Harmful mutations are responsible to cause genetic disorders and cancer. A genetic disorder mostly caused by the alteration in one or a few genes. cystic fibrosis is an example of a harmful mutation in humans. A mutation can cause the body to produce mucus that responsible for clogs the lungs and blocks ducts in digestive organs. it has very harmful effects on living organisms.
purifying selection is also known as natural selection responsible for the selective removal of deleterious alleles. This helps in stabilizing selection through the removal of deleterious genetic polymorphisms that comes via random mutations.
2. Neutral mutations are changes in DNA sequence occur and that changes are neither beneficial nor detrimental for the survival and reproduction of an organism. so zero changes have been observed in the case of neutral mutations.
3. Darwin's theory states that the mechanism of evolution comes with the variation that presents among organisms within a species. The evolution of the species affects rates of survival and reproduction.
DNA variants that alter gene expression and contribute to variation in many phenotypic traits. example trans-acting variants, which are located on different chromosomes from the genes they affect, and these are an important source of variation inheritable gene expression.
Selective sweep Genetic hitchhiking, or genetic draft or hitchhiking effect, in this case, allele changes frequency due to it is under the natural selection. a selective sweep is an example of genetic hitchhiking between a site under selection and a linked site not under selection. This is a kind of an unexpected linkage.
Explain the difference between the concept of the traditional use of the word “genetic mutation” and...
Read just the long paragraph below and explain in your words the hypothesized evolutionary processes (note, more than one are in play) proposed to remove slightly deleterious alleles from the gene pool. Keep in mind the importance about balance between mutation rates and the consequences to individual fitness. "At first sight, it appears paradoxical that nearly neutral mutations in essential immune genes will be efficiently removed from the species’ gene pool despite having no easily discernible impact on the immune...