Sen. Warren 1/512 U.S. Indian

[morrobay]

With (1/2)^g = 1/512
g (log 1/2) = log 1/512
g (-,3) = -2.7
So she had an Indian relative back 9 generations

But suppose the DNA shows 1/689 * Indian .00145, log = -2.83
then: g (-.3 ) = -2.83
and she has Indian relative(s) going back , g = 9.46 generations.
How is that interpreted regarding generations/relatives ?
* 1/689 was random pick

 

[Tom.G]

How is that interpreted regarding generations/relatives ?

That she had more than one relative from that bloodline in her ancestors.

 

[Vanadium 50]

There are many oversimplifications already in the thread.

First, it's not 1/512. It's between 6 and 10 generations back.

Second, the comparison is not with North American Indian DNA. It's a calculation based on similarity between Sen. Warren's and Central/South American Indian DNA.

Third, the power-of-two rule assumes ancestors are either all Indian or all-not-Indian. In real life, this is not true. One could go back 20 generations and have 1522 of those ancestors been Native American, and get your 1/689 number, even though it is not a power of 1/2.

Fourth, the power-of-two rule assumes a lack of intermingling between and across generations that is not present in real data. For example, Prince Charles is descended from Queen Victoria on both sides.

 

[Greg Bernhardt]

Just a preemptive friendly notice to stick to the math/logic of the OP problem and not devolve into politics. Thanks!

 

[StatGuy2000]

Second, the comparison is not with North American Indian DNA. It's a calculation based on similarity between Sen. Warren's and Central/South American Indian DNA.

[Note: In this post, I will use the word "Native American" to refer to the indigenous peoples of both North and South America. I will not use the word "Indian" to avoid any confusion with the people of India.]

At the risk of going off-topic, I am aware that present Native Americans of North America have been reluctant to volunteer samples of their DNA, in part due to suspicion over the intentions of the research due to past history of abuses done against them in the name of research, as well as concerns about tribal sovereignty.

But I do have a question as to what extent the DNA of Native Americans differ between those who are indigenous to North America and those who are indigenous to Central and South America. Further, I am curious as to the extent of the genetic diversity between the indigenous peoples of North America.

The reason for my curiosity is that there have been recent reports of the extent of genetic diversity among the indigenous peoples of Mexico. See the link below.

https://www.sciencemag.org/news/2014/06/people-mexico-show-stunning-amount-genetic-diversity

I believe the original publication referenced in the above popular article can be found below.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4156478/

Given the relative size of Mexico compared to the whole of Canada and the United States, it's not unreasonable that the factors cited in the article above about genetic diversity within the Native American populations in Mexico (due to geographic isolation and population bottlenecks, among other factors) might also apply to those who are indigenous to what is now Canada and the US.