Abstracts » Zoology and wildlife conservation

Genetics and geography

Article Abstract:

The continuing debate among geneticists about using analysis of mitochondrial DNA (mtDNA) to investigate human origins has demonstrated that statistically reliable techniques for deducing genealogies are imperative. In 1987 researcher Allan Wilson and colleagues announced that mtDNA variation indicated that humanity's ancestor was probably an African woman who lived about 200,000 years ago. Wilson's group reached this conclusion by choosing the genealogical tree with the fewest changes as the parsimony criterion requires. However, other researchers dispute this result.

Genetic aspects, Human population genetics

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Human origins

Article Abstract:

The human mitochondrial tree devised by R.L. Cann and others to represent human origins can be improved by removing arbitrary separations between the branches while maintaining the branches' different lengths. These changes produce an irregular star-shaped plot that brings out the data's overdispersal. The resulting phylogenetic tree conforms to data indicating that the African branch is not as sharply differentiated from the tree as was formerly thought, weakening the African 'Eve' hypothesis.

Models

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A clean energy programme

Article Abstract:

Mitochondrial cells have evolved a number of antioxidant defences, including enzymes such as superoxide dismutase to scavenge superoxide, as well as catalase and glutathione peroxidase to degrade hydrogen peroxide in order to combat reactive oxygen species (ROS). A new study has concluded that a homeostatic loop exists between mitochondria and ROS and that this loop is orchestrated by a nuclear protein called PGC-1[alpha].

Science & research, Maryland, Analysis, Nucleotide sequence, Base sequence, Structure, Oxidative stress

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