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Mitochondrial DNA offers another advantage over autosomal DNA.
There are generally 2 to 4 copies of each chromosome in each cell (1 to 2 from each parent chromosome).
the mt DNA genome has been used to estimate branching patterns in peoples around the world, such as when the new world was settled and how.
The problem with these studies have been that they rely heavily on mutations in the coding region.
Molecular anthropology has been extremely useful in establishing the evolutionary tree of humans and other primates, including closely related species like chimps and gorillas.
While there are clearly many morphological similarities between humans and chimpanzees, for example, certain studies also have concluded that there is roughly a 98 percent commonality between the DNA of both species.
The process of recombination, if frequent enough, corrupts the ability to create parsimonious trees because of stretches of amino acid subsititions (SNPs).
When looking between distantly related species, recombination is less of a problem since recombination between branches from common ancestors is prevented after true speciation occurs.
By examining DNA sequences in different populations, scientists can determine the closeness of relationships between populations (or within populations).While recombination may occur in mt DNA, there is little risk that it will be passed to the next generation.As a result, mt DNA become clonal copies of each other, except when a new mutation arises.This allowed the use of mitochondrial DNA to determine that the relative age of the human population was small, having gone through a recent constriction at about 150,000 years ago (see #Causes of errors).Mitochondrial DNA has also been used to verify the proximity of chimpanzees to humans relative to gorillas, and to verify the relationship of these three species relative to the orangutan.