DNA

Something about human mitochondrial DNA testing that might stir a thought or two. I loved the fact that the genealogical line was in fact carried by the mother, however, it might be a little outdated, since I heard that ‘they’ are now also able to isolate and identify the paternal ancestor.

"While mtDNA is useful for forensic examinations, it has also been used extensively in two other major scientific realms. First, there are a number of serious human diseases caused by deleterious mutations in gene-coding regions of the mtDNA molecule, which have been studied by the medical profession to understand their mode of inheritance. In addition, molecular anthropologists have been using mtDNA for almost a decade to examine both the extent of genetic variation in humans and the relatedness of populations all over the world. Because of its unique mode of maternal inheritance it can reveal ancient population histories, which might include migration patterns, expansion dates, and geographic homelands. Recently mtDNA was extracted and sequenced from a Neanderthal skeleton. These results allowed anthropologists to say with some conviction that modern humans do not share a close relationship with Neanderthals in the human evolutionary tree. While all the applications of mtDNA, including forensic, are relatively recent, the general methods for performing a mtDNA analysis are identical to those used in molecular biology laboratories all over the world for studying DNA from any living organism. There have been over a thousand published articles regarding mtDNA.MtDNA has advantages and disadvantages as a forensic typing locus, especially compared to the more traditional nuclear DNA markers that are typically used. As mentioned above, mtDNA is maternally inherited, so that any maternally related individuals would be expected to share the same mtDNA sequence. This fact is useful in cases where a long deceased or missing individual is not available to provide a reference sample but any living maternal relative might do so. Because of meiotic recombination and the diploid (bi-parental) inheritance of nuclear DNA, the reconstruction of a nuclear profile from even first degree relatives of a missing individual is rarely this straightforward. However, the maternal inheritance pattern of mtDNA might also be considered problematic. Because all individuals in a maternal lineage share the same mtDNA sequence, mtDNA cannot be considered a unique identifier. In fact, apparently unrelated individuals might share an unknown maternal relative at some distant point in the past."–

Copyright 2002 by Terry Melton, Mitotyping Technologies, LLC from: http://www.mitotyping.com/dna.htm