SUMMARY-DNA Testing, Cherokee-ness & Revised Question
Miles Abernathy (miles@mail.utexas.edu)
1 Mar 1995 20:41:21 GMT
NEW QUESTION:
Is there a relatively inexpensive DNA test to suggest whether or not a
person of primarily European extraction might have a Native American
ancestor (1.5 to 3% N-A ancestry)?
I understand that some DNA tests are relatively inexpensive, e.g., those
to establish paternity...recently I even saw a roadside billboard
advertising the service. Also, over the years anthropologists have done
extensive sampling of different population groups to determine ancient
migration paths, so there must be lots of information already on Native
American DNA's.
An aside, for those who suggested that a look at the genealogical records
might easily / quickly answer the original question: I have been doing
genealogy off and on for 8 years. Many Southern US civil records were
destroyed at the end of the Civil War, causing large gaps in knowledge of
the period before then. In other words, the information doesn't always
exist in written form :-)
===
ORIGINAL QUESTION:
I grew up "knowing" that I was of Scotch-Irish extraction, but a recent
"out of the blue" genealogical find suggests that I might have a
ggg-grandmother who was Georgia Cherokee.
This got me to thinking...is there an inexpensive DNA test to determine
(imply?) if I am indeed part Cherokee? I wouldn't expect evidence that
would hold up in a court of law...this is just for fun. Thank you.
===
REPLIES RECEIVED:
The DNA locus for "Cherokeeness" is not known. There is no DNA test for such.
===
No.
===
Sorry to give you a disappointing answer, but DNA test are routinely *very*
expensive to run. We do them in the laboratory at the medical school.
It is also rather difficult to determine "race" via a DNA test, because the
distribution of DNA is extremely variable for populations at large, and there
are currently no markers to distinguish one race from another (no piece of
DNA that says "I'm caucasian" or "I'm asian" or "I'm african.")
.
DNA testing is mainly useful for determining matches between close family
members, or looking for genetic disease markers. Determining race is still
a few years away. :)
Checking county court documents and genealogical records should prove to be
more fruitful. Best of luck
===
No. First, very few lab tests can be qualified as "inexpensive". Second, that's
simply not how it works. The human geneome is largely conserved among
individuals (every person's DNA is more than 90% identical to the next guy).
There's little consensus on what constitutes a race, but generally it's under-
stood that a race is a geographically or culturally isolated group with
low levels of outbreeding with other groups. This makes certain allelotypes
more frequent in some populations than others, but the actual genes are the
same (i.e., there are more than a dozen genes, each with 3 or 4 different
forms, that affect human epidermal pigmentation; the gene's are common to all
people, regardless of their skin color, but different combinations of the
different type, differing diets, and health considerations actually affect the
expression of those genes and yield a specific skin color).
For you to estimate your "Cherokeeness", you would need to determine the
frequency of all of the different allelotypes for each gene in the Cherokee
population, next, you'd need to determine the deviation of that distribution,
you'd also need to locate and specifically sequence all of those genes. Next,
you'd need to sequence your DNA for all of the genes with a statistically
distribution than those within your control group (Scotch-Irish), then you
could estimate, within a predictable amount of error, your similarity to
the Cherokee population.
Of course, that sort of sequencing technology is far beyond the scope of
modern technology (we could do it, mind you, with current technology, but at
10 years per person for testing, and a minimal sample size of 25 Scotch-Irish
and 25 Cherokee people (they must be pure breeding), you're talking 5,000
years to get a result (and that presumes you have as many people working on
it as currently work on the human genome project).
A much more convenient method is that which has been employed by generations.
If your great-great-great-grandmother was Cherokee, that's 5 generations,
meaning that she contributed roughly 3% of your genome (and a little less than
10% of that contributes to phenotypic (visible) traits).
===
Um, no, there is no `Cherokee gene' that can be tested for. Native
tribal affiliations are not coded for in DNA. Sorry.
If you want to verify the existence of a relative, I'd suggest
reading a book on genealogy, then checking the appropriate legal
and historical records.
===
Nobody said, "Yes, my company sells such a DNA test for $29.95." Perhaps
someone will have a more encouraging answer to my revised question. Thanks
to all who took the time to answer!
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