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Post by Dienekes on Dec 30, 2005 2:27:02 GMT -5
OK, please answer this question. How do we know L3 is older than either M or N? M and N have mutations that L3 doesn't have. So, M and N occurred after L3 was already in existence. L3 mtDNA mutated and became M. Of course, this brings us to the question of how do scientists determine what the original form and what the mutated form is. For example, if a locus has C in one piece of DNA and G in another, how do they know whether the original form was C or G? This is achieved by comparing human DNA with that of our closest relatives, usually the chimpanzee. The ancestral form of the allele is that which is shared by human and chimp.
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Post by greatness on Dec 31, 2005 19:57:46 GMT -5
yeah that comparing of DNA that Dienekes talks about is precisely what ppl like Spencer Wells have done and by and large their work supports an Out-of-Africa theory.
To me this is what I believe. PPL moved outta Africa, first branch were veddoid/Aboriginal type that moved by boat to southern Asia and to Australia. Meanwhile other ppl separated by the Saharan desert from the negroid ancestors changed in Proto-Caucasians. These ppls migrated out to the mid-east and then in Iran and/or central Asia these ppl formed the bulk of modern day Caucasians while another group branched off and headed north forming the Mongoloid race which was to eventually move into east Asia and cross over into America to form Amerids.
Now what is interesting is scientists have recently discovered bones from South America that resemble Aboriginal Australoid type more than Amerid. Now that means Australoids might have been the first to the Americas?? Well that really puts something else into the puzzle dont u think.
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Post by galton on Jan 1, 2006 5:25:10 GMT -5
It’s similar to the question that you asked about A and B. M and N are downstream from L3. M and N “branched” from L3, so they are obviously younger. M and N have mutations that L3 doesn't have. So, M and N occurred after L3 was already in existence. L3 mtDNA mutated and became M. Of course, this brings us to the question of how do scientists determine what the original form and what the mutated form is. For example, if a locus has C in one piece of DNA and G in another, how do they know whether the original form was C or G? This is achieved by comparing human DNA with that of our closest relatives, usually the chimpanzee. The ancestral form of the allele is that which is shared by human and chimp. I understand how researchers can determine one marker's age compared to another, but how do they determine the age of a marker to begin with? Even if M and N is downstream from L3, M and N could be the oldest surviving Eurasian markers, not necessarily younger African markers, right? theoccidentalquarterly.com/vol4no1/raf-plural.html
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Post by ibra on Jan 2, 2006 22:05:30 GMT -5
So, is it safe for me to say that the age of a genetic marker equals the number of generations multiplied with the number of mutations of that marker? Calculating the generations back for a specific marker is the hard part; multiplying that number by a constant (estimated) is much easier. If a mutation happened 100 generations ago, that means it’s probably around 2300 years old. I’m not a statistical encyclopaedia, so I dont' know the exact method(s) used for dating mtDNA. You probally need advanced genetics and college statistics to understand mtDNA dating, not grade 6 geometry (your level).
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Post by galton on Jan 2, 2006 22:25:42 GMT -5
So, is it safe for me to say that the age of a genetic marker equals the number of generations multiplied with the number of mutations of that marker? Calculating the generations back for a specific marker is the hard part; multiplying that number by a constant (estimated) is much easier. If a mutation happened 100 generations ago, that means it’s probably around 2300 years old. I’m not a statistical encyclopaedia, so I dont' know the exact method(s) used for dating mtDNA. You probally need advanced genetics and college statistics to understand mtDNA dating, not grade 6 geometry (your level). You have more insults for me. So without a deep understanding of the subject matter of mtDNA and genetic studies, you've decided to take the Out of Africa hypothesis as gospel. Now who sounds like a parrot? A rude one, yet.
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Post by ibra on Jan 2, 2006 23:16:25 GMT -5
Calculating the generations back for a specific marker is the hard part; multiplying that number by a constant (estimated) is much easier. If a mutation happened 100 generations ago, that means it’s probably around 2300 years old. I’m not a statistical encyclopaedia, so I dont' know the exact method(s) used for dating mtDNA. You probally need advanced genetics and college statistics to understand mtDNA dating, not grade 6 geometry (your level). You have more insults for me. So without a deep understanding of the subject matter of mtDNA and genetic studies, you've decided to take the Out of Africa hypothesis as gospel. Now who sounds like a parrot? A rude one, yet. I can back up my point relatively well. All you can do is hotlink ad hominem and ask pointless questions. I often feel I’m debating a monkey, not just a parrot. Just a hint, but your inability to debate makes you seem rather unintelligent to most posters.
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Post by galton on Jan 2, 2006 23:39:35 GMT -5
I can back up my point relatively well. All you can do is hotlink ad hominem and ask pointless questions. I often feel I’m debating a monkey, not just a parrot. Just a hint, but your inability to debate makes you seem rather unintelligent to most posters. So far, the only ability you seem to excel at is an abusive, provocative and rude tone and manner in a dialogue.
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