Mingling of two haplogroups

[hap]

Let us say that the Y DNA haplogroup of a certain person is J2. Does it mean that every single one of the male ancestors of that person were of J2 lineage, or can can there be lineages of other haplogroups interspersed throughout the ages? I strongly suspect that the latter case is more realistic. If it is so, is it a question of the majority haplogroup winning over the others or it doesn't work that way?

[rod]

Let us say that the Y DNA haplogroup of a certain person is J2. Does it mean that every single one of the male ancestors of that person were of J2 lineage, or can can there be lineages of other haplogroups interspersed throughout the ages? I strongly suspect that the latter case is more realistic. If it is so, is it a question of the majority haplogroup winning over the others or it doesn't work that way?

The J2 is the haplogroup of his father's, father's, father's....... father. The haplogroup of his mother's father, father's mother's father, etc aren't reflected in his y-dna haplogroup.

[bobr]

Let us say that the Y DNA haplogroup of a certain person is J2. Does it mean that every single one of the male ancestors of that person were of J2 lineage, or can can there be lineages of other haplogroups interspersed throughout the ages? I strongly suspect that the latter case is more realistic. If it is so, is it a question of the majority haplogroup winning over the others or it doesn't work that way?

No, it does not mean that every single ancestor before you was a J2. The mutation for J2 happened at a certain time in the pass. Prior to the J2 mutations, there was a founding Haplogroup that originally came from africa. You are descended from the man/men from that founding Haplogroup that first received the J2 mutation.

[hap]

OK but since the time when the mutation to J2 happened could there have been other haplogroup ancestors or only J2 ancestors since the present haplogroup is J2?

[EBurgess]

As Bobr was saying. J2 is only a description for a step/mutation along the way.


For Example, today you may describe yourself as American, your family may have emigrated from England, but originally they were from the Midde East or mediteranean and before that from Africa.

So describing a person as J2 is really only describing a step that happened in the distant past. Scientist may break down J2 into further sub-groups, some of which may be localized to new geography.

The model says we are all related it just depends on how far back in time you care to look. J2 is just a branch off a bigger tree.

[josh w.]

As I understand hap's question the answer is "No".

[EBurgess]

OK but since the time when the mutation to J2 happened could there have been other haplogroup ancestors or only J2 ancestors since the present haplogroup is J2?

Between the present time and thousands of years ago when the J2 mutation occured there are certainly downstream mutations. Scientists just have to find and catalogue these. But the predecessor to J2 was always just one super-haplogroup I think this was F. You can be J2a, b, c, d , e, or f, and f is even broken down further into J2f1, J2f2.

Saying the "present" haplogroup is J2 is just the best description that can be given today.

Have a look at the chart it may explain at a glance what you want to know:

http://www.ftdna.com/haplotree.html

[josh w.]

I think hap was asking a important but simple question . In the past 20,000 years or so J2s can only descend from J2s. (In turn J2s can only ultimately descend from Js and Js can only ultimately descend from Fs. The ultimate events, J TO J2 and F to J, took place more than 20,000 years ago. Since then J2s have always been J2s) In other words, J2s cannot descend from Is or Ks or Rs or Qs etc.

[josh w.]

P.S. For simplicity sake, I did not deal with the possibility of evolution repeating itself . For the same reason I omitted discussion of subclades. J2fs are still J2s. One further question regarding the origination of J2 vis a vis J1 remains unresolved.

[EBurgess]

P.S. For simplicity sake, I did not deal with the possibility of evolution repeating itself . For the same reason I omitted discussion of subclades. J2fs are still J2s. One further question regarding the origination of J2 vis a vis J1 remains unresolved.

Josh you are correct, his question was quite simple after all. I just wanted to tell him that J2 is not a beginning nor the end. It is just a step on the way.

I am not certain what you mean by J2 vis a vis J1? Downstream from F you have one mutation that gives J then you have one for either J1 or J2? Did I miss something?

Incidentally you have some individuals who are neither and remain undifferentiated J*.

[josh w.]

On the J1--J2 matter, I have read (I forget where) that J2 might have emerged out of other subclades rather than directly out of J. Help, if anyone is more familiar with this issue.

[josh w.]

Found it! See article by Underhill and collaborators " Y chromosome sequence variation and the history of human populations" (2000) Nat. Genet. Vol 26.

Underhill et al. suggest that J2 evolved out of J1 by a T to G transversion.

[EBurgess]

Thanks Josh,

I wonder if since that 2000 article, the issue has been resolved? But the fact that such a thing is possible, an intermediate marker discovered later is very interesting

[josh w.]

Enjoyed the discussion. I agree that haplogroups are not static categories.

[hap]

Thanks guys for the input. Some things cleared up.