Question

Explain why the time of the most recent common ancestor estimated from variation in a sample of two DNA sequences sampled from different populations does not equal the divergence time of the populations. (you should probably have at least 1 equation in your answer).

Answer 1

Ans: Genetic divergence is the process in which two or more populations of an ancestral species accumulate independent genetic changes through time.

Population Genetics is the experimental and theoretical study of inherited variations in populations and its modulation in time and space.

The relation between the phenotype and genotype varies in simplicity from character to character . For Example At one extreme the phenotype may observe DNA sequence of a stretch of the genome and phenotype disappears and in fact directly observing the genotype .At the other end lies the bulk characters of interest.

The example of various blood group of humans are considered . The qualitatively distinct phenol-type of a given blood group - say , the MN group are enclosed by alternative alleles at a single locus and the phenotype are in sensitive to environmental variations .

The Variations consists of two stages as

1. Description of phenotype.

2. Translation of phenotype.

If there is perfect one - to one correspondence between genotype and phenotype then these two steps merge into one as the MN blood group.

Genotype for Alleles at MN blood group.

1.For Egyptian ..... 0.489(MN)

2.For German .....0.507(MN)