Rispondi a: BAMBINI INDACO 2° LETTERA ANONIMA

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Richard
Richard
Amministratore del forum

Questo parla di mutazioni rilevate nei bimbi, ma che teoricamente porterebbero a problemi di salute
http://www.physorg.com/news137669677.html
Clinical analysis of blood samples from almost 3,000 infants born in north Cumbria, England, showed that at least 1 in 200 individuals in the general public harbor mitochondrial DNA mutations that may lead to disease.

This study gives us, for the first time, a measurement of the number of these carriers of pathogenic mitochondrial DNA mutations in the general population. One in every 200 individuals is a lot of people – around 1.5 million people in the United States alone. ”

Dr. Samuels commented: “These new clinical measurements have given direct evidence for the widespread incidence of pathogenic mitochondrial DNA mutations in the human population. These findings emphasize the pressing need to develop effective ways to interrupt the transmission of these mutations to the next generation.”

Citation: Hannah R. Elliott, David C. Samuels, James A. Eden, Caroline L. Relton, Patrick F. Chinnery (2008) Pathogenic mitochondrial DNA mutations are common in the general population. American Journal of Human Genetics 83(2): 254-260. doi:10.1016/j.ajhg.2008.07.004

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http://scienceandevolution.blogspot.com/2007/07/mitochondrial-dna-and-human-evolution.html

Mitochondrial DNA and Human Evolution
What is Mitochondrial DNA?
This is DNA found outside of the cell nucleus. They are inherited only from the mother, which allows tracing of a direct genetic line. They also have their own genome of about 16,500 bp. Each contains 13 protein coding genes, 22 tRNAs and 2 rRNAs. ..

So Mitochondrial DNA tells us what?
The out of Africa theory has support from Mitochondrial DNA. But these conclusions have been criticised for a lack of statistical support. This is due to the fact that a small section of the Mitochondrial DNA called the D-loop, about 7% of the genome has been used for the studies. Statistically, the out of Africa theory is not well founded. Here is why. Three main problems with data from the D-loop section have been identified:
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Conclusions
The phylogenetic tree reconstructed with this latest dataset of complete mitochondrial genomes provides support to the 'recent African origin' theory..

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Where Is Human Evolution Heading?
The race's DNA is changing faster than ever; what it means for our descendants
http://www.usnews.com/articles/science/2008/07/24/where-is-human-evolution-heading.html

New mutations. Until recently, anthropologists thought that human evolution had slowed down. But last December, Hawks reported that it has actually accelerated 100-fold in the past 5,000 to 10,000 years. He figured that out by comparing chunks of DNA among 269 people from around the world. Over time, DNA accumulates random mutations, just as the front of a white T-shirt tends to accumulate spots. The bigger the chunks of DNA without random spots, the more recently it had been minted. Using this system, Hawks concluded that recent genetic changes account for about 7 percent of the human genome. Much of the increase, he says, has been fueled by the growth of the world's population, which has expanded by a factor of 1,000 over the past 10,000 years. Having more people increases the odds of mutations.

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