Genetic Diversity Case Study

Superior Essays
An Overview of the Determinant of the Genomic Diversity

Genetic diversity provides variation in which that selection can act upon and it determines the response of population towards environmental change. Therefore, knowledge in genetic diversity is crucial for developing breeding strategies and also for the management of endangered species. Understanding the determinant genetic diversity is also essential for resolving the long-standing riddle in population genetics, the disproportionately narrow range of the genetic diversity compared with the large magnitude difference of population size across tree of life, known as Lewontin’s Paradox (Lewontin, 1974).

Genetics polymorphism varies across genome and thought to be as the result of balance
…show more content…
Smukowski et al. (2011) also suggested that there is a heterogeneity in recombination rate across genome and between species, so to get a valid analysis of linked selection, the difference in recombination rate should be accounted for. Begun and Aquadro (1992) showed that the silent site diversity scale positively with recombination rate in Drosophila and this is interpreted as the effect of episodic positive selection. Further, Corbett-Detig et. al (2015) showed that neutral site diversity in large population has relatively weaker correlation with recombination than in smaller population. The reasoning is that, large Ne intensifies selection processes and eliminates more neutral diversity. Another issue is that the recombination itself is inherently mutagenic, so it promotes higher diversity and thus, confounding the effect of linked selection. However, correlation between species divergence (which is proxy for mutation rate) and the level of recombination is insufficient for explaining all pattern of genetic …show more content…
For example, bottleneck event following human migrated out of Africa, makes the genome of human in other continent as the subset of African genome with less in diversity (Yu et al., 2012). Demographic effects also influence the outcome of the linked selection. Signal for linked selection is expected to be weaker in the subdivided population (with high population differentiation index, Fst). For example, if the hard sweep occurs locally (in subpopulation), the signature of linked selection will be masked in global scale. It is also predicted that in expanding population, there are many newly arises mutations which become the subject for selection, so the effect of linked selection will be more prevalent than in population at

Related Documents

  • Improved Essays

    Throughout the lab, we examined bunnies in different scenarios/major events which impacted allele frequencies of the bunnies. The hypothesis for Part A was that if there is no natural selection, then the allele frequency for the bunnies will not change. This proved to be true, given that all the Generation 1 bunnies were unaffected. For example, in all charts for Generation 1, the total alleles were 100 and alleles F and f both equally had 50. This demonstrates that if the allele frequency did not change, then the bunny population had no change in quantities of alleles, proving the first hypothesis to be correct.…

    • 989 Words
    • 4 Pages
    Improved Essays
  • Improved Essays

    However, it is likely to increase the variations in populations that are local. In the occurrence of genetic drift, the frequencies of alleles can change as a result of sampling errors. The random change is likely to occur from one generation to another. Genetic drift is very conspicuous in small populations.…

    • 964 Words
    • 4 Pages
    Improved Essays
  • Improved Essays

    1. DNA Structure and Function DNA is the type of organic compound that stores the genetic information in a living organism. DNA is made up of two strands of nucleotides, which include a phosphate group, five carbon sugar, and a nitrogenous base. Each individual strand in held together by strong covalent bonds (a bond formed as a result of the distribution of electrons between atoms). The two strands are then joined to each other by hydrogen bonds between complementary bases.…

    • 1255 Words
    • 6 Pages
    Improved Essays
  • Improved Essays

    Fruit Fly Lab Report

    • 679 Words
    • 3 Pages

    For this lab we conducted a population genetics study on the frequency of wild and apterous flies within a small population of fruit flies. The fruit fly Drosophila works well for genetic and evolutionary geared studies because they have a relatively short generation time but are intricate enough to reveal some biological principles that are parallel to many different kinds of eukaryotic organisms. When exposed to artificial selection in laboratory experiments, fruit flies have experienced dramatic changes behavioral and evolutionary traits within ten generations or less (Goldsmith, 1991). It is important to note that wild flies have wings and apterous flies do not. The purpose of artificial selection is for humans to modify species over generations by intentionally breeding two organisms with the objective of acquiring a specific trait.…

    • 679 Words
    • 3 Pages
    Improved Essays
  • Superior Essays

    Taster Genotype Lab Report

    • 1539 Words
    • 7 Pages

    Results: TAS2R38 Gene he TAS2R38 gene, encodes a protein that allows people to taste the bitter chemical PTC. To begin the experiment, each student tasted two separate pieces of paper to show their individual phenotypes. The first paper was a control, and the second paper was PTC paper. If the individual tasted a bitterness while tasting the PTC paper, they were classified as a taster, and if nothing was tasted they were classified as a non-taster (Leicht 165). Once these expected phenotypes were noted, it was time to test everyone’s genotype.…

    • 1539 Words
    • 7 Pages
    Superior Essays
  • Improved Essays

    Beetle Selection Report

    • 1283 Words
    • 5 Pages

    The hypothesis declared that orange and red beetles would be lessened to 0 while the yellow beetle coloration succeeded, the initial state and increase in frequency of allele in yellow beetles to 100% made the decrease in genetic variation. This was seen in the outcomes of the exercise, unfavorable traits were removed through natural selection and such individuals with much fitness, in this case, the yellow beetles, succeeded because of the profusion of the resources (only 120 beetles may stay alive at any point) and yellow has a selective advantage in such environment like dessert since they are favorable, while orange and red beetle coloration have unfavorable characteristics since it would be easier to spot them. This is associated to scrutiny established in the literature which stated that such combination of phenotypes are results of being favored by the environment while diminishing the rate of recurrence of the erstwhile which are increasingly not favorable through the natural selection method (Holt 1997). However, the outcomes showed the change in genetic variation of species through the removal of alleles in the gene pool was caused by natural selection and genetic drift.…

    • 1283 Words
    • 5 Pages
    Improved Essays
  • Improved Essays

    Genetic Differences

    • 527 Words
    • 3 Pages

    Founder effect occurs if a small group moves from home to new settlements, this new family will have dissimilar allele frequencies from the original population it may be by chance either lack come alleles or have high frequency of others while population bottlenecks occurs when a large decrease in the size of an original population can eliminate a large amount of genes. 23. How does mutation increase genetic variation in a way that crossing over and independent assortment do not? This because during mutation selection removes deleterious alleles however, dangerous recessive alleles are preserved in heterozygotes and are reintroduced by mutations 24. How does mutation alter allele frequencies?…

    • 527 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    Genetic Lab Criteria

    • 422 Words
    • 2 Pages

    Mutations are random permanent changes in the genome of an organism that may or may not result in phenotypical variation. Mutations can be stimulated by external events such as exposure to ionizing radiation as well as internal events such as errors in DNA replication like double strand breaks. In lab, we focused on mutations that exhibit phenotypic advantage or disadvantage to an organism in their respective habitats. The necessity of higher or lower mutation rates will vary based on whether the organism is in need of mutations to survive. Within this scope, different of resource, climate, and predator-based conditions will benefit high mutating strains and low mutating strains of the same species, respectively.…

    • 422 Words
    • 2 Pages
    Improved Essays
  • Great Essays

    Natural Selection Lab

    • 1562 Words
    • 7 Pages

    This can be seen in nature with the moths that were camouflaged with the background and were not eaten or killed off whereas those that could camouflage with the environment would not be killed as easily and could pass their genes on to the next generation (Butterfly Conservation, 2002). In the second experiment, the students were given a green “environment” bin with different sized squares within. It was noted that the smaller squares were still remaining within the bin at the end of the experiment and this is because they were much harder to spot when compared to the size of the other, larger ones. This occurs in the environment when a larger selection of a species is killed off because of its larger size, or because it is hiding the smaller selection of a species beneath it, allowing the smaller selection to survive and pass its genes on to the next generation. The previous data is firmly supported by the data that the students acquired by performing the experiment.…

    • 1562 Words
    • 7 Pages
    Great Essays
  • Improved Essays

    For example, an allele starting with a frequency of 0.01 has 1% chance of being fixed in a population. It is very interesting to see genetic diversity at many loci though natural selection is constantly acting in a population. Even in the presence of natural selection, genetic diversity can be manifested by mutation, selection itself, negative frequency dependent selection and recessive alleles can minimize effect of natural selection. Mutations give rise to novel alleles which in turn produce new phenotypes in a population. This will change allele frequencies, and if any allele is harmful to the organism, natural selection will try to minimize the effect of that allele.…

    • 575 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    Genetic Drift Papers

    • 518 Words
    • 3 Pages

    Genetic Drift is chance rise and fall in the regularity of the arrival of a gene in a tiny remote population, apparently owing to coincidental rather than normal selection. Usually, genetic drift takes place in very small inhabitants, where rarely occurring alleles face a better opportunity of being absent. Once it starts, genetic drift will carry on up until the allele involved is missing by the inhabitants or up until it is the lone allele existing in a population at a specific locus. Genetic drift is normal following population bottlenecks, which severely cut the amount of a population. Now, the result is the loss of extraordinary alleles and a decline in the gene pool.…

    • 518 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    Genus Homo Evolution

    • 1376 Words
    • 6 Pages

    SNPs are nucleotides that bond with complementary pairs. Due to microevolutionary forces such as gene flow and the founder effect, the alleles increase over time. The founder effect measures the percentage of alleles in small populations. Based on observing the skulls, Neanderthals have similar features to the Homo heidelbergensis. For example, the Neanderthal populations emerged based on the unique sequence of SNPs.…

    • 1376 Words
    • 6 Pages
    Improved Essays
  • Decent Essays

    Evolution Lab

    • 389 Words
    • 2 Pages

    In this lab, we used computer simulations to investigate about the forces of evolution. Evolution is when alleles changes over time in a population. There are four major forces of evolution. These forces may increase or decrease gene diversity, meaning they can introduce new alleles or extinct some alleles. One of the forces is mutation.…

    • 389 Words
    • 2 Pages
    Decent Essays
  • Improved Essays

    Genetic drift is a mechanism of evolution that occurs by random chance rather than natural selection. In genetic drift, a population experiences a change in the frequency of a given allele, prompted by random luck rather than a need for adaptation. This differs from natural selection, in which allelic frequency is altered based on the fittest genes surviving to reproduce and the weaker genes dying off. Genetic drift tends to be a phenomenon amongst smaller populations, while natural selection holds sway in larger populations. Life (168)…

    • 360 Words
    • 2 Pages
    Improved Essays
  • Improved Essays

    By weeding out the weak or non-beneficial genes from the pool, large populations can quickly shift over short generational spans to press the most advantageous survival genetics into prevalence. There are three types of natural selection that occur in nature: directional selections, stabilizing selection and disruptive selection. Directional selections is directly tied to traits that affect physical characteristics such as size, color and pattern. These changes often occur quickly because they are directly responsible for survival of the population. Stabilizing selection occurs because certain traits have a higher survival chance such as the size of the organism effecting its ability to nourish itself and it’s young in a certain environment.…

    • 1103 Words
    • 5 Pages
    Improved Essays