Little problem

[hrvat22]

Please help .. how is it possible that in sites old about 5 or 6 thousand years exist haplotypes old 21 or 18 thousand years ..

http://eurogenes.blogspot.hr/2015/06/r1b-from-vucedol-period-hungary.html

https://en.wikipedia.org/wiki/Starčevo_culture
Starčevo culture, 5500 and 4500 BCE
haplotip I2a1(P37.2)

I-P37 (age: 18490 ybp)


http://yfull.com/tree/I-P37/




https://en.wikipedia.org/wiki/Lengyel_culture
Lengyel culture 5000-3400 BC.
haplotip I2 (M438)

I2 (age: 21644 ybp)


http://yfull.com/tree/I2/



Thanks..

 

[MOESAN]

I don't know:
in a big population, even recent, some rare old forms (upstream SNPs) can survive at ridiculously low %s - in Europe we have today persons bearing very old '*' SNPs (it's to say old forms without new KNOWN mutation) but in the case of ancient DNA it could be the bad condition of the recupered DNA that prevents to go further in detailed downstream SNPs ? Sorry for my curious english. And also new mutations are being discovered after, not always searched at some stages of surveys?

 

[sparkey]

Let's start with the basics. Do you understand the difference between these terms?: "Clade age" (called "SNP formed" on ysearch, which is a bit misleading), "TMRCA," and "sample age."

The calculated ages that you're quoting include a sample age and a TMRCA, which are different concepts. The sample age is the age of one carrier of the subclade. The TMRCA is how long ago the most recent common ancestor of all known carriers of the subclade lived. The clade age, meanwhile, is even older than the TMRCA--it is when the clade split from its closest relatives.

 

[Sile]

Let's start with the basics. Do you understand the difference between these terms?: "Clade age" (called "SNP formed" on ysearch, which is a bit misleading), "TMRCA," and "sample age."

The calculated ages that you're quoting include a sample age and a TMRCA, which are different concepts. The sample age is the age of one carrier of the subclade. The TMRCA is how long ago the most recent common ancestor of all known carriers of the subclade lived. The clade age, meanwhile, is even older than the TMRCA--it is when the clade split from its closest relatives.

so , how is it that a branch can split into 2 branches and these 2 have far different TMRCA, as an example below

branch 11000ybp
splits at 7300ybp into 2 branches

branch 1 is TMRCA of 6100ybp

branch 2 is TMRCA of 1400ybp

why the TMRCA discrepancy is both branch 1 and 2 formed 7300ybp

 

[sparkey]

so , how is it that a branch can split into 2 branches and these 2 have far different TMRCA, as an example below

branch 11000ybp
splits at 7300ybp into 2 branches

branch 1 is TMRCA of 6100ybp

branch 2 is TMRCA of 1400ybp

why the TMRCA discrepancy is both branch 1 and 2 formed 7300ybp

The obvious answer to that is that TMRCAs are independent of each other.

In practice, this pattern might arise if one of the branches has a second split soon after the first split.

 

[Sile]

The obvious answer to that is that TMRCAs are independent of each other.

In practice, this pattern might arise if one of the branches has a second split soon after the first split.

you would not suspect that branch 2 branched out of branch 1 much later.......that is, the one with TMRCA 6100 is the "parent" of branch 2 with TMRCA of 1400 ?

 

[sparkey]

you would not suspect that branch 2 branched out of branch 1 much later.......that is, the one with TMRCA 6100 is the "parent" of branch 2 with TMRCA of 1400 ?

You already said that branch 1 and branch 2 branched from each other at 7300ybp, so by definition 1 isn't the parent of 2. Am I misunderstanding you?

 

[oriental]

The way I see it is that there are siblings. Sibling 1 has one offspring who has mutation TMCR 1. Sibling 2 having the same DNA as Sibling 1 has great great grand child who gets Mutation 2 TMCR 2 years later. TMCR 1 is not the parent of TMCR 2 but Sibling 2 is the direct ancestor of TMCR 2.

 

[Sile]

You already said that branch 1 and branch 2 branched from each other at 7300ybp, so by definition 1 isn't the parent of 2. Am I misunderstanding you?

yes , I see

then why the 4700years of TMRCA difference..........is it that they have still found no common ancestor!

TMRCA is a fickle beast and its benefit isn't as great as its meant to be

 

[hrvat22]

I thought that it was haplotype detected several years ago and today is outdated ... as well as Croatian I2a type which was 25,000 years old and today is 2000 years old ..

It would be logical that is not possible find a haplotype old 18,000 years in the site old 7000 years .... only if is detected basic branch..I2a1(P37.2)

 

[hrvat22]

Let's start with the basics. Do you understand the difference between these terms?: "Clade age" (called "SNP formed" on ysearch, which is a bit misleading), "TMRCA," and "sample age."

The calculated ages that you're quoting include a sample age and a TMRCA, which are different concepts. The sample age is the age of one carrier of the subclade. The TMRCA is how long ago the most recent common ancestor of all known carriers of the subclade lived. The clade age, meanwhile, is even older than the TMRCA--it is when the clade split from its closest relatives.

I2 (M438) is always been old about 20,000 years ago, I know, because it was claimed 10 years ago that Croats are 20,000 years old in the Balkans.

..

experimental tree for I2a year 2015...
I2 (age: 21644 ybp)

 

[sparkey]

I thought that it was haplotype detected several years ago and today is outdated ... as well as Croatian I2a type which was 25,000 years old and today is 2000 years old ..

It would be logical that is not possible find a haplotype old 18,000 years in the site old 7000 years .... only if is detected basic branch..I2a1(P37.2)

Oftentimes, especially with ancient samples, we can't get very specific with the subclade. As a result, even if we'd like to drill down further, we might not know anything more than a sample being "some sort of I2" or "some sort of I2a" or something. So even though the sample may be 7000 years old, we may only be able to assign it to a subclade with a TMRCA of 18,000 ybp.

 

[oriental]

Mutations do not occur at a regular rate as have been assumed. It is the stress from the environment, chemical, radiation, etc. even diet eg. some young Iranians drank their tea hot (very hot) and it was found that many of those tea drinkers developed throat cancer. I think it is non-linear. Of course, it is more difficult for the environment and conditions may have changed that brought about the mutation. Ancient times had hardly any changes i.e. hard, clean living and occasional climate changes so mutations would come very slowly and by the current method ancient DNA sample might appear young as they did not mutate much.