Genetic genealogy and East Asian print collections

Ken KleinUniversity of Southern California

March 30, 2011

Y-chromosome and mitochondria DNA

• Autosomes: recombination of chromosome strands from both parents

• Non-combinant DNA which is passed from generation to generation with virtually no alteration.

1. Y-DNA, passed from father to son, unaltered by DNA from the mother.

2. mtDNA, passed through the maternal line, mother to daughter, unaltered.

Y-DNA and mtDNA as genealogical tools

• Both are passed unaltered but with a predictable rate of mutation

• y-DNA and the written and published record in East Asian societies.

Stix, Gary, “Traces of a Distant Past,” Scientific American 299:1 (January 2008): 59.

Pointing out some obvious facts

We receive our DNA, our genetic code from two parents.

Two generations back, we trace our DNA back to four grandparents.

Five generations back, each of us has 32 direct ancestors …

_______________

And that number doubles again for each additional generation we trace back.

Twenty-five generations back, each of us has

33,554,532 (2^25)statistical ancestors.

This is not say, however, that there are that many different ancestors.

The case of the 楊 Yeung (Yang) lineage of

中山 Zhongshan (formerly 香山 Xiangshan), Guangdong Province

南雄

香山

Three genealogical sources for the Xiangshan Yeung’s

• 楊家譜 . 25 generations of descent from 楊大章 , the youngest of four brothers in the 3rd generation, down to 20th century. (photocopy of original manuscript record)

• 楊氏族譜 Published record (1848; 1877; 1933) of 23 generations of patrilineal descent from 楊大刚 , the eldest of the four brothers in the 3rd generation, but only fully articulated from the 19th to the 23rd generation.

• 楊家譜 . 6 generation manuscript of descent from 楊明組 , 16th generation descendant in another line.

楊氏族譜 (1933)

Yeung marriage partners, 楊明組 and 楊大章 lines

Total marriages Jeng 鄭 Wong 黃 Next highest

楊明組 12 3 (25%) 4 (33%) 1 (8%)

楊大章 112 17 (15%) 12 (11%) 8 (7%)

楊大章 (lineage of 25) 22 6 (27%) 4 (18%) 2 (9%)

Yeung marriage partners楊大刚 line

Total marriages Tam 譚 Cheng 程 Next highest

楊元規 217 34 (15.2%) 23 (11.0%) 16 (7.4%)

(Jeng 鄭 and Wong 黃 marriages constituted 4.6% and 1.8% of the total)

The 25th generation descendant has a Jeng female ancestor in the 5th, 7th, 10th, 12th, 15th, & 20th generations (red).

And a Wong female ancestor in the 2nd, 19th, 21st, & 22nd generations (yellow).

5

10

15

20

25

5

10

15

20

25

If Wong wife (22G) was a great-great granddaughter of the father of Wong wife (19G), there would be an overlap of statistical ancestors 25 generations back in the amount of 2^18 (262,144)—for just that one repeat appearance in the family tree.

If, on top of that, Wong wife (21G) was the granddaughter of the brother of Wong wife (19G), there would be another overlap of statistical ancestors of the same size.

5

10

15

20

25

Replicated several times over, this helps to illustrate that, among the the 33+ million statistical ancestors a 25th generation Xiangshan Yeung has, some individuals—many individuals—will appear multiple times. The actual number of ancestors 25 generations back is likely quite limited.

From this perspective, we can view a 25 generation genealogy as consisting not so much of 33+ million individuals but of a skein of lineages that intersect repeatedly in complex fashion.

Here’s where I finally get back to genetic genealogy.

中山石岐杨氏 Zhongshan Shiqi Yang Lineage : Haplogroup L

Originated in Southwest Asia approximately 18,000 years ago.

So what use is the DNA test?

o Verification of patrilines

o Genetic profile of a locality

o Comparability with other localities

o Asian American issues

o Help to sort out paper son thickets

中山石岐杨 / 邓 / 林 Zhongshan Shiqi Yang/Deng/Lin Maternal Haplogroup M (“Seafarers”)

Originated in area between East Africa and Persian Gulf approximately 65,000 years ago.