Mitochondrial matrix
The cytosolic, intermembrane space, compartment has a water content of 3.8 μl/mg protein, while the mitochondrial matrix 0.8 μl/mg protein. It is not known how mitochondria maintain osmotic balance across the inner mitochondrial membrane, although the membrane contains aquaporins that are believed to be conduits for regulated water transport. Mitochondrial matrix has a pH of about 7.8. Mitochondrial DNA was discovered by Nash and Margit in 1963. One to many double stranded mainly circular DNA is present in mitochondrial matrix. Mitochondrial DNA is 1% of total DNA of a cell. It is rich in Guanine and Cytosine content. Mitochondria of mammals have 55s ribosomes.
Mark Stoneking
Stoneking came to prominence both in the academic and media circles with his work on mitochondrial DNA variation among different human populations. He started under the supervision of Allan Wilson and following the pioneering work of his senior graduate student, Rebecca Cann. Cann had collected data from different human populations, including those of Asians, Africans, and Europeans. Then Stoneking added data from aboriginal Australians and New Guineans. In 1987, after a year of pending, their paper was published in "Nature" in which their findings indicated that all living humans were descended through a single mother, who lived ~200,000 years ago in Africa. The common hypothetical mother is dubbed Mitochondrial Eve, and the concept directly implies recent African origin of modern humans, hence, the underpinning of the so-called "Recent Out of Africa" theory. In spite of criticisms, and religious antagonisms, even after two decades he still holds this view to be as valid as any scientific theory since a number independent research also corroborates their original human mtDNA phylogenetic tree.Stoneking has appeared in