Monday, June 20, 2011

Thoughts on Classical and Scientific Genealogy

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In comments to my post Saturday Night Genealogy Fun - Who is Your Most Recent Unknown Ancestor? reader Tamura Jones said:

"I am disappointed that neither Randy nor any of his respondent gave the correct answer.
It is so hard to leave the dogmas and misconceptions of traditional genealogy behind and become a scientific genealogist?

"The scientific genealogy truth is simple: for most of you, your most recent unknown ancestors are your parents.

"Neither family stories nor vital records constitute any proof of a biological relationship.  Only if a DNA test confirmed who your biological parents are, does the MRU status move from your parents to your grandparents, etc.  It may be hard to face that fact, it may be an unpopular truth, but it is not less true because of that..."


A followup comment by reader Martin noted that:

"So in order to be a scientific genealogist, one needs to dig up (literally not figuratively) one's ancestors and submit them to DNA tests? [not to mention that you just called all of our parents liars]"

For background reading, an interested person should read some of Tamura's posts on his website (Internet Explorer 8 and earlier IE versions don't work, IE9 does, Firefox or Chrome work), including:

 (18 August 2010)
 (29 August 2010)
 (14 June 2011)
*  and related articles (see the list at the end of each article)

1)  My opinion is that Tamura is technically correct:  If we have not obtained DNA samples, and performed the requisite DNA tests on them, then we have not identified our ancestors beyond any doubt whatsoever - only a DNA match can conclusively and exclusively prove that a person is genetically related to a specific father and a specific mother. 

So how many DNA samples of your ancestors do you have?  I don't have any!  I have only a Y-chromosome DNA test and a mitochondrial DNA test for myself - with a limited number of markers.  If I had an autosomal DNA test performed on myself, and on my brothers, and on my father's siblings children or grandchildren, I might be able to construct a DNA proof study that supported an assertion that myself and my brothers were sired by our purported father and mother, that my father and his siblings were sired by the same man and born of the same mother, and that my mother was sired by her purported father and mother (this would be difficult since my mother and both of her parents were only children!). 

A Y-chromosome DNA test could provide clear and convincing evidence if two persons with a known patrilineal line have a common male ancestor in their line, and can provide clear and convincing evidence that the claimed patrilineal lines descend from that most recent common ancestor (MRCA).  However, it would not provide absolute proof that a specific male fathered the specific child - it could have been a brother, uncle or cousin with a patrilineal line back to the MRCA.

Likewise, a mitochondrial DNA test could provide clear and convincing evidence if two persons with a known matrilineal line have a common female ancestor in their line.

The above assertions are why many genealogists are interested in tracing family lines from X-great-grandparents to living distant cousins - they can be used to provide evidence of relationships and corroborate "traditional," "official" and "legal" genealogical research (to use Tamura's terms).

If, as Tamura suggests, DNA tests to determine genetic traits are performed on every person born, and also on their parents, then the "scientific genealogy" aspect could be vigorously pursued.  I doubt that such testing will be done routinely in the near future.

2)  My opinion is that Martin is also technically correct.  Since few genealogy researchers have had extensive DNA tests done on their parents, grandparents, great-grandparents, etc. back in time, then we cannot pursue "scientific genealogy" even several generations back.  Even "digging up our ancestors" (if that's possible in every case) won't help much - my layman understanding is that Y-DNA is not available from cadavers, and no DNA is likely available from cremated remains. 

The vast majority of the "official" records we use to determine relationships between parents and children are correct to the best of the knowledge of the information providers (usually parents or close relatives) and the information receivers (clerks, courts, etc.).  Our "classical genealogy" research has to use this information because it is what we have.  Aside from the limited DNA test results, it is what we have to work with for deceased persons. 

Not every source is based on original source material, and therefore each information source must be evaluated as to its quality as it pertains to the assertion under consideration. We also know that original and derivative sources do not contain absolutely correct information due to lies, bias or errors.  

The "official" records that we search for, collect and use, along with the "unofficial" records (newspaper articles, family notes and Bibles, gravestones, etc.), form a body of evidence which we analyze and evaluate, infer from and, possibly, draw conclusions from about names, dates, places, relationships, and events. 

From this evidence, we have proof that is imperfect - perhaps only to the clear and convincing level at best.   This is why the "Genealogical Proof Standard" is important and should be used to gather evidence, analyze and draw conclusions for events pertaining to our ancestors and their families. 

3)  The bottom line for each of us is to:

*  Use all of the research methods we have available to us in homes, businesses, government offices, repositories, and websites to obtain records.  Those records should be as close to the original source as possible, should provide primary information about the assertion, and that provides direct evidence of the event. 

*  Use DNA tests to determine patrilineal and matrilineal lines as best we can, and monitor the technology to determine if autosomal DNA tests will provide more helpful information.  
4)  I think that every experienced genealogy researcher has a basic understanding of the "classical" vs. "scientific" debate, and accepts the fact that we cannot prove, to a level of "without any doubt," the names, dates, places, events and relationships of our ancestral families.  We do the best we can with the information we have, and are open to acceptance of new, or more authoritative, information. 

5)  Thank you to Tamura and Martin for their opinions.  I welcome more comments to this post, and request that those comments be respectful and contribute to the discussion.

The URL for this post is http://www.geneamusings.com/2011/06/thoughts-on-classical-and-scientific.html

(c) 2011. Randall J. Seaver. All Rights Reserved. If you wish to re-publish my content, please contact me for permission, which I will usually grant. If you are reading this on any other genealogy website, then they have stolen my work.

11 comments:

Drew Smith said...

I don't think that "scientific" genealogy would require "beyond any doubt whatsoever". That's certainly not the standard for science in general.

Rather, science requires only that there is a theory (an explanation) well supported by the evidence, and that no alternative theory is backed by equivalent (or better) evidence.

I think the confusion here is in the use of "science" to refer to certain aspects of biology, and "science" to refer to a process of creating and supporting useful theories. They don't mean the same thing.

Tonia said...

Bravo, Randy.

I've done Y, mtDNA, and autosomal testing and so, far, haven't proved a thing. For me, DNA testing is interesting, but traditional genealogy is fun!

Daniel Dillman said...

I agree with Martin and Drew. There's doubt, and there's reasonable doubt. Even our legal system identifies this, and someone must be proven guilty beyond a reasonable doubt, not to 100% absolute certainty. How can we hold genealogy to a higher standard, especially when ,as has been pointed out, we can't obtain the DNA for testing beyond a couple of generations in most cases, less in some.

That said, the issue most of us face is getting to that Reasonable Doubt place beyond the first few generations. A preponderance of the evidence will get us there, if we can find and document it.

Tamura Jones said...

What Drew mentions is a principle known as Occam's Razor;
go with the simplest explanation that fits all the facts.

Banai Lynn Feldstein said...

I saw nothing in the original question that asks us to go beyond the scope of "traditional genealogy" into this so-called "scientific genealogy" Tamura talks about. His opinions about genealogy often have nothing to do with what the rest of us think of the subject; trying to redefine "vital records", saying that marriage is not a vital event, etc. Genealogy is about learning our family history and where our people come from, not the DNA they passed down. Maybe his ideas would be more welcomed among biologists because that seems to be the subject of the day. Sometimes I think he comes up with these opinions just to start arguments.

Martin said...

At some future date (not within my lifetime) there will be a genealogical database of mitochondrial DNA that you can use to further prove something (or contrarily disprove something).

If you think that classical genealogy is expensive (and it is), then the proposed scientific genealogy is astronomical. Drop $400 on DNA tests for each and every ancestor, where known, or that elusive female to female descendant to prove mtDNA. Wow!

George Geder said...

Wow!

'Scientific' and 'traditional' genealogy would, by their nature, leave so much out of my family history. Namely, the stories of the people who mean so much to me.

If I couldn't prove - with certainty - that my relatives and my Ancestors were connected to me, that would make their stories and lives irrelevant. Ain't gonna happen; I'll tell you right now.

If 'Scientific' and 'traditional' genealogy are the horns of dilemma on the proverbial bull's head, then I aim for 'right between the eyes' with Family History to set the soul free and put the mind at ease.

This argument or debate is not faith-based and it would place a lot of blended and non traditional families out of the genealogical picture completely. Ain't gonna happen in my family tree.

Peace & Blessings,
"Guided by the Ancestors"

George Geder said...

Wow!

'Scientific' and 'traditional' genealogy would, by their nature, leave so much out of my family history. Namely, the stories of the people who mean so much to me.

If I couldn't prove - with certainty - that my relatives and my Ancestors were connected to me, that would make their stories and lives irrelevant. Ain't gonna happen; I'll tell you right now.

If 'Scientific' and 'traditional' genealogy are the horns of dilemma on the proverbial bull's head, then I aim for 'right between the eyes' with Family History to set the soul free and put the mind at ease.

This argument or debate is not faith-based and it would place a lot of blended and non traditional families out of the genealogical picture completely. Ain't gonna happen in my family tree.

Peace & Blessings,
"Guided by the Ancestors"

Michael Hait said...

I would like to state that I agree with Drew's statements about the nature of science (there is a reason why everything in science comes down to "theories") and George's statements about family history.
I also posted on this subject at http://michaelhait.wordpress.com

Geolover said...

When the distant legal ancestor A's DNA is not tested, even multiple legal cousins' well-matched DNA results is not "clear and convincing" evidence that "A" is the common ancestor. It is evidence that there probably ~is~ a common ancestor, with no surety as to who the ancestor might be. 6th-great-gran Abigail could have had a long-term relationship with a neighborhood philanderer.

There were assuredly many times when the woman who gave birth did not know who the child's father was.

d76b632e-9d4c-11e0-b5c6-000bcdcb5194 said...

Some bloggers are doing a great injustice to Tamara Jones by pretending that she said that genetic genealogy (she calls it biological genealogy) is a replacement for paper genealogy.
I don't know what source these bloggers are using, but I don't think they read her blog.
I've been checking out her blog posts, and Tamara's "scientific genealogy" is TOTALLY DIFFERENT from what they say it is!
The BCG says genetic testing is "another valuable tool in our intellectual toolbox," but the Genealogical Proof Standard does not tell us how to use it.
What Tamara did is very interesting: she figured out a way to use DNA tests without ever contradicting your GPS conclusions!
Instead of one genealogy, her "scientific genealogy" has three inter-related genealogies: your genetic tree, your paper tree and one in between that links them together. It is a unintuitive yet somehow very logical solution.
I think this "scientific genealogy" is an intriquing concept that deserves our serious consideration, but I am not sure that I agree with her.
One genealogy is more than enough trouble! ;)

L.