Genetic Diversity Case Study

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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
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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

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