Mitochondrial Eve Research Articles

An Array of Science from Mitochondrial Eve to EUVE

An Array of Science from Mitochondrial Eve to EUVE

The continuing case of the Florida dentist.

The subject of the analysis of viral DNA fingerprinting associated with the alleged human immunodeficiency virus type 1 (HIV-1) infection of a number of dental patients in Florida is scrutinized. Reference is made to the recent findings of Ou et al. which are published in this same issue of Science. Scientific and ethical issues are examined as well as the issue of what determines an appropriate level of statistical and scientific reliability for public policy or judicial review. The significance for a resolution of reliability questions is that in the absence of a medical position others unfamiliar will draw conclusions. The public is amenable to changing life styles without necessarily strong statistical evidence. There is agreement among nations however that the HIV-1 evidence is strong enough to recommend use of condoms and medical gloves and invest in research. Legal action mandates the highest statistical significance in the determination of verdicts without a reasonable doubt. In the Florida dental case data a manuscript and the review process became entangled in legal machinations. Out et al. and other scientists involved in legal action have a responsibility to decide in advance appropriate statistical criteria. The difficulties that arise from studies of the transmission of the HIV 1 virus are represented either in Ou et al. and the C2-V3 domain of transmission from dentist to patient or from the Wolinsky study of transmission from infected women to unborn children. The Ou et al. study of the 7 infected dental patients and the 35 local controls (LC) is questioned on the randomness of the LC sample the process of polymerase chain reaction (PCR) and the statistical tests of significance used (Wilcoxon rand sum statistic the distinction between cloned sequences and direct sequences the appropriateness of the bootstrapping procedure). The phylogenetic relationships among variants varies with modes of transmission and tree building is a difficult art and science. The Ou et al. study is considered a pioneering effort in the use of DNA typing to resolve individual viral transmission events but the issue is complex and statistical flaws have already occurred in the Wilson et al. hypothesis of African Eve.

"African Eve" Backers Beat a Retreat

"African Eve" Backers Beat a Retreat

Paradise lost: Mitochondrial eve refuted

Being based solely on neontological data, all «unique parent» evolutionary hypotheses, of which «Mitochondrial Eve» is one, fall into the category ofscala naturae. Mathematical treatment of neontological data bases, using cladistic approaches does not confer the status of scientific hypotheses onto such scenarios. Apart from these fundamental problems, such hypotheses are flawed on a number of other bases, including the fact that there is a proportion of parental contribution to mitochondrial lineages, despite widely publicised statements that mithocondrial DNA in mammals is «strictly» maternally inherited. Other weaknesses of «unique mother» hypotheses on that their proponents endeavour to describe the evolution of diploid organisms on the basis of variability in extant haploid organelles, the evolution of which is delinked from that of the diploid organism. A further difficulty is that it is not possible to reconstruct interspecific relationships on the basis of intraspecific variability. There is a general ignorance among proponents of «unique mother» hypotheses regarding the distribution of biological variability on the surface of the globe, a fact which renders the molecular clock inaccurate, and which upsets the simplistic proposal that molecular diversity equates with time. «Unique mother» scenarios are also invalidated by the presence of shared chromosome and other polymorphisms in african great apes and humans at similar percentages in the different lineages, a fact which indicates that these evolving populations did not experience «bottlenecks». These and other difficulties effectively refute the «Mitochondrial Eve» hypothesis, which in any case much resembles creationism of a special kind, in which the offspring of a breeding pair are visualised as belonging to a species different from its parents. Such extreme examples of the punctuational mode of evolution are highly likely to be incorrect.

Evolution of mitochondrial DNA in Drosophila subobscura

The colonization of the New World by the Palearctic species Drosophila subobscura was first detected in 1978 in South America and around 1982 in western North America. The ensuing dramatic expansion of the species, in territory as well as numbers, provides an opportunity for studying evolution in a scale rarely possible. We have used 10 restriction endonucleases to analyze the mitochondrial DNA (mtDNA) of individuals from 23 widely dispersed localities. Only two mtDNA composite morphs have been detected in the Americas. None of the two morphs has been found in Africa, and only one in the Atlantic islands; but both are widespread in Europe, which provides no clue of the precise geographic origin of the colonizers. The amount of nucleotide-substitution polymorphism detected in D. subobscura is typical for animals, but it is greater in the Old than in the New World, presumably due to the recent colonization by a limited number of colonizers. Assuming standard evolutionary rates of mtDNA base substitution, the mtDNA morphs found in D. subobscura can be traced to a single one that existed no less than one million years ago. We argue against the inference that the D. subobscura flies now living descend from only one or a few females that lived at that time. This type of inference, which we call the "Mother Eve hypothesis," has been made to conclude that the human population went through a severe constriction about 200,000 years ago, so that all living humans descend from only one or a few women who lived at that time. The Mother Eve hypothesis is fallacious.