mtDNA. Can I have an introduction on it...

[Prove]

I have read that mtDNA findings are not very valuable, and are much less reliable than Y Chromosome findings? Is this true? Is it due to mtDNA's susceptibility to mutation?

Or is mtDNA derided simply because it is a poor instrument for geneaological endeavours? (Most surnames being patrilineal)

I am rather a newbie at this, so if anyone more learned in this field can give me a poke in the right direction or elaborate to some degree on this subject, it'd be much appreciated.

[Prove]

I found a nice little gif that explains somewhat how it is passed along in generations:



Still, are mtDNA samples still useful in accounting for regional relatedness in population genetics?

[Artemidoros]

Prove said:

Still, are mtDNA samples still useful in accounting for regional relatedness in population genetics?

I am a newbie as well but not a shy one. I don't mind giving my opinion (especially if I have borrowed it from somebody who knows more ).
I think mtDNA is still very useful, in some cases more useful than anything else. It depends on what you are looking for. Both mtDNA and Y-chromosomes can reveal a lot but in population genetics one must be very cautious. Their results can be very misleading, so I would only accept them if there is a reasonable explanation and hopefully autosomal DNA evidence to back them up.

[Slaven]

Will someone explain to me, please, what actually means when one say that ,for example, some population consists of 40% Eu19, and 60 % of Eu18.

Does it mean that:

1. 40% of the sample contain Eu 19 marker and 60% contain Eu 18;
Let's say the sample consists of 100 people. Now 40 % of them contain Eu19 and 60% contain Eu18; or

2. Every person in the sample contain averagely 40% of Eu19 and 60 % of Eu 18.
Something like making a profile of an average member of the population?

In other words is it possible that one person may contain more markers like Eu 18, Eu 19, Eu 7.......etc, or one person can have only one marker?

Thank you in advance.

[Artemidoros]

Slaven said:

Will someone explain to me, please, what actually means when one say that ,for example, some population consists of 40% Eu19, and 60 % of Eu18.

Does it mean that:

1. 40% of the sample contain Eu 19 marker and 60% contain Eu 18;
Let's say the sample consists of 100 people. Now 40 % of them contain Eu19 and 60% contain Eu18; or

2. Every person in the sample contain averagely 40% of Eu19 and 60 % of Eu 18.
Something like making a profile of an average member of the population?

In other words is it possible that one person may contain more markers like Eu 18, Eu 19, Eu 7.......etc, or one person can have only one marker?

Thank you in advance.

One person can only have one Y-Chromosome marker no matter how mixed his ancestry is. Only males have that particular marker which is passed endlessly from father to son. Mt-DNA is passed from the mother to both her sons and daughters but only her daughters can pass it on, as you can see from Prove's diagram. The knowledge of one's mt-DNA and Y-chromosome markers is of limited value, as they only point to two out of thousands of ancestors. They are very useful in Population Genetics but the results have to be interpreted, which is not easy.

[Slaven]

Artemidoros, thanks a lot.