Evolution: Please answer all parts thoroughly and accurately. 6. Assume the neut

Question

Evolution: Please answer all parts thoroughly and accurately.

6. Assume the neutral mutation rate varies across the genome of Drosophila melanogaster and also assume that the sister species D. simulans exhibits similar patterns of neutral mutation rate variation across homologous genomic regions. If one estimated across the genome, nucleotide heterozygosity in D. melanogaster and divergence to D. simulans, what would the correlation look like between nucleotide heterozygosity and nucleotide divergence (would it be zero, positive, or negative) and why?

7. At a particular gene an investigator observed 2 synonymous and 6 non-synonymous differences between two species. If a total of 40 polymorphisms were observed in sample of alleles for one of the species, what would the expected number of synonymous and non-synonymous polymorphisms in this species be under neutrality?

Explanation / Answer

Population genomics ,the study of genomic wide patterns of sequence of variations with in and between closely related species,can provide a comprehensive view of the relative importance of mutation ,recombination,natural selection and genetic drift on evolution .it can also provide fundamental insights into the biological attributes of organisms that are specifically shaped by adaptive evolution .One of approch for ,generating population genomic datasets is align a DNA sequences from the whole genome shotgun projects to a standard reference sequence .We used this approach to carry out whole geneome analysis of polymorphism and divergence in Drosophila simulans,a close relative of the model system ,D.melogaster.We find that polymorphism and divergence flutuate on large scale across the genome and these fluctuations are probably explained by natural selection rather than by variation in mutuation rates .Our analysis suggests that adapative protein evolution is common and is often related to biological processes that may be associated with gene expression ,chromosome biology ,and reproduction and tThe approches presented here will broad applicability to future analysics of population genomic variation in other systems ,including systems.

7.The ratio of non synonomous substitution i.e...that alter the amino acids and that do not atler the amino acids has been extensively used an indicator selected pressure.As with the recombination ,this mechanism has not been addresed extensively in IIHHNV lineages ,in which the rates of amino acid replacements exceeded those of synonyoms subtititutions when compared to neutral expectations for genetic drift and mutation

Related Questions

Navigate

• Browse (All)
• Browse E
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.