DNA For Everyone
Originally posted to DNA for Everyone.
So, 60 Minutes has broadcast a report on the tracing of DNA. Leslie made a statement, "The are just two bits of DNA which remain pure. The Y chromosome which passes directly from father to son. And something called mitochondrial DNA which passes unchanged from mother to child." Logically speaking, if the mDNA ( Read more... )
So, 60 Minutes has broadcast a report on the tracing of DNA. Leslie made a statement, "The are just two bits of DNA which remain pure. The Y chromosome which passes directly from father to son. And something called mitochondrial DNA which passes unchanged from mother to child." Logically speaking, if the mDNA ( Read more... )
I read about one of those tests taken by a reporter who was, say, a white guy of European descent with maybe some Jewish blood way back somewhere. He came out with those characteristics, but also markers for sub-Saharan Africa and something like native South American Indian. His reaction was to try to figure out how people from those areas could have ended up in his bloodline, where my reaction is to seriously wonder whether the test is using the right markers. After all, some particular gene variant that is common in South American Indians could also have appeared elswhere, perhaps a mutation in one of this guy's parents! I am extremely pro-science, and these companies selling gee-whiz genetic testing don't seem to all be taking enough care in their process.
From a recent story having to do with orchid evolution-
http://www.arn.org/blogs/index.php/literature/2007/08/30/dinosaurs_walking_among_orchids
This fossilized orchid pollinarium from 15-20 million years ago helps date the origin of orchids to about 80 MYA, partly through looking at current orchids' DNA and assuming a constant rate of mutation.
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Wells pointed out dating markers really is assuming a certain number will happen at an average rate over time. Technically, I don't think these markers are genes. Genes are coherent sequences that cause things to happen. These are aberrations between coherent sequences which have no value biologically. Except now.... In mDNA and in the Y chromosome, we can catalog these mistakes and locate individuals with them in common as having shared ancestry.
Something to remember about South American Indians is the Spanish were in sexual contact with them for almost 200 years starting about 500 years ago. Part of the Diaspora was in Spain before, during, and after this period. By the same token, sub-Saharan African could have Moorish ancestors who mixed with the Spanish Diaspora. So, it seems reasonable to me this individual could have ancestors all over the place.
Oh... there is a book, Abraham’s Children: Race, Identity and the DNA of the Chosen People, specifically discussing the spread of Jewish DNA all over the place. Your comment inspired a marketer working on the behalf of the author to email me about doing a review or Q&A on it. :)
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Dr Oliver Curry seems to think that geographical and social mobility is a new thing, and that this will produce uniformly coffee coloured humans in 1,000 years. Oliver has perhaps not been to Brazil, where black African, white European, and Amerindian have lived side by side and bred together for many centuries. The Brazilians have not gone coffee coloured, they in fact still show a wide range of skin pigmentation, from black to tan. This is because skin pigmentation seems to be coded for by a fairly small number of genes and probably doesn’t blend and even out as Oliver - a political theorist, not a scientist - suggests.
http://www.badscience.net/?p=316
Why is it you have to be a scientist to understand science?
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