How many ancestors share our dna

[1798]

For those who think that they may be connected to a pedigree line.
http://www.genetic-inference.co.uk/b...share-our-dna/

[josh w.]

For those who think that they may be connected to a pedigree line.
http://www.genetic-inference.co.uk/b...share-our-dna/

Thanks, Very Informative

[1798]

Thanks, Very Informative

I have seen a few "who do you think you are" programs and I find it amusing that some people think that they are related to someone famous. If they were dna tested they might find that it is only by paper that they are connected.

[thetick]

I have seen a few "who do you think you are" programs and I find it amusing that some people think that they are related to someone famous. If they were dna tested they might find that it is only by paper that they are connected.

You would need many other's DNA tests to prove you are related to others far back in your tree. So a single DNA test would not prove anything unless other relatives are tested.

[1798]

You would need many other's DNA tests to prove you are related to others far back in your tree. So a single DNA test would not prove anything unless other relatives are tested.

They would also need a pick and shovel.

[Barreldriver]

Saw reference to this in a CoopLab version (seems the genetic-inference.co.uk article was updated even to refer to the CoopLab version). Both were very useful, however it would be nice to see exactly when the presented math no longer applies.

I've made the mistake of applying it to a very high (k), e.g. 200 generations, and rolled out with some very unrealistic results (it was pointed out to me after the fact that CoopLab made a note that the math only pertains to a certain time-scale, I should have caught it on my own but meh).

One of the CoopLab visual aids terminates at 14 generations, so I'd feel safe using the math within 14 generations or less. 10 generations seems like a good point given that many genealogies won't go farther than that, if even that far.

When (k) is set at 10, one has around 438 autosomal DNA ancestors in comparison to the 1024 ancestors-on-paper (assuming no-inbreeding/overlap of ancestors).

2^k *(1- exp(-(22+33*(k-1))/2^(k-1)))

2^10 *(1- exp(-(22+33*(10-1))/2^(10-1)))

1024 *(1- exp(-286/512))

1024 *(1- exp(-0.55859375))

1024 *(1- 0.57201289165)

1024 *(0.42798710835)

438.25879895

[1798]

Saw reference to this in a CoopLab version (seems the genetic-inference.co.uk article was updated even to refer to the CoopLab version). Both were very useful, however it would be nice to see exactly when the presented math no longer applies.

I've made the mistake of applying it to a very high (k), e.g. 200 generations, and rolled out with some very unrealistic results (it was pointed out to me after the fact that CoopLab made a note that the math only pertains to a certain time-scale, I should have caught it on my own but meh).

One of the CoopLab visual aids terminates at 14 generations, so I'd feel safe using the math within 14 generations or less. 10 generations seems like a good point given that many genealogies won't go farther than that, if even that far.

When (k) is set at 10, one has around 438 autosomal DNA ancestors in comparison to the 1024 ancestors-on-paper (assuming no-inbreeding/overlap of ancestors).

2^k *(1- exp(-(22+33*(k-1))/2^(k-1)))

2^10 *(1- exp(-(22+33*(10-1))/2^(10-1)))

1024 *(1- exp(-286/512))

1024 *(1- exp(-0.55859375))

1024 *(1- 0.57201289165)

1024 *(0.42798710835)

438.25879895

My autosomal dna comes from a small area within walking distance. So some of us are like the small tribes in the jungle. The scientists can see this from our FF tests.If a stranger arrives with new dna then he or she is absorbed into our gene pool. It would take a lot of people to change it.

[mamoahina]

My autosomal dna comes from a small area within walking distance. So some of us are like the small tribes in the jungle. The scientists can see this from our FF tests.If a stranger arrives with new dna then he or she is absorbed into our gene pool. It would take a lot of people to change it.

Where are you from?

In my situation it is like this, although I don't know if I can say from walking distance. But I come from a place where we are a product of successive founder's and bottleneck populations that produced a lack of diversity. Scientists have written about us, even Bennett Greenspan was surprised to see how closely my mother matched with people from 4,000 away showing up as 1st cousin/aunt-niece relationship who have no ties except whatever we had over 500 years ago.

But because of this, it's easy to pinpoint the foreign strain/ancestor but at the same time it's not easy to distinguish among other similar admixed people as me when it comes to looking for the non-endogamous branch connections.

[1798]

Where are you from?

In my situation it is like this, although I don't know if I can say from walking distance. But I come from a place where we are a product of successive founder's and bottleneck populations that produced a lack of diversity. Scientists have written about us, even Bennett Greenspan was surprised to see how closely my mother matched with people from 4,000 away showing up as 1st cousin/aunt-niece relationship who have no ties except whatever we had over 500 years ago.

But because of this, it's easy to pinpoint the foreign strain/ancestor but at the same time it's not easy to distinguish among other similar admixed people as me when it comes to looking for the non-endogamous branch connections.

I am from a townland in Ireland were my 16 GG grandparents lived within ten miles of my birthplace.

[1798]

Saw reference to this in a CoopLab version (seems the genetic-inference.co.uk article was updated even to refer to the CoopLab version). Both were very useful, however it would be nice to see exactly when the presented math no longer applies.

I've made the mistake of applying it to a very high (k), e.g. 200 generations, and rolled out with some very unrealistic results (it was pointed out to me after the fact that CoopLab made a note that the math only pertains to a certain time-scale, I should have caught it on my own but meh).

One of the CoopLab visual aids terminates at 14 generations, so I'd feel safe using the math within 14 generations or less. 10 generations seems like a good point given that many genealogies won't go farther than that, if even that far.

When (k) is set at 10, one has around 438 autosomal DNA ancestors in comparison to the 1024 ancestors-on-paper (assuming no-inbreeding/overlap of ancestors).

2^k *(1- exp(-(22+33*(k-1))/2^(k-1)))

2^10 *(1- exp(-(22+33*(10-1))/2^(10-1)))

1024 *(1- exp(-286/512))

1024 *(1- exp(-0.55859375))

1024 *(1- 0.57201289165)

1024 *(0.42798710835)

438.25879895

http://www.digitaljournal.com/news/e...article/388647

Humans do this as well as the monkeys. Most marry within there own kind.