[Ger-Poland-Volhynia] DNA Testing Explained
lradke at procognis.com
Sat Sep 14 11:46:33 PDT 2013
I have been following the discussion on DNA and thought I would add some
background in case it is of use to those who might be considering testing.
All humans are 99.8% the same, however the 0.2% that we differ can have a
large impact on who we are. Differences in dna are made up of insertions
(extra pieces of dna that others don't have), deletions and SNPs (pronounced
snips). For the most part significant insertions and deletions are not
consistent with life and result in miscarriage, a stillborn child, or severe
birth defects (like down syndrome). For most of us, the 0.2% that we differ
is made up of snips - minor variation in our dna.
When the human genome was mapped in 2003, it gave us a baseline to compare
to. Scientist were then able to determine locations in the genome where
humans were known to vary. It is estimate that the average human varies from
the baseline in ~3 million locations. Of these locations, ~2 million are
well known to scientist because variation has been seen in many people, the
remaining ~1 million are more recent and may only be seen in certain
families or ethnic groups. Testing the full genome is still expensive
(around $5,000 usd), but companies like 23andme, have created an inexpensive
($99 usd) test that looks at 1 million of the well known locations. This is
called an Autosomal test and is also now offered by ftdna and ancestry.com.
In any of these snip locations, you may have the ancestral version or the
newer, derived version. You inherit one copy from each parent, so you can
have two ancestral copies, two derived copies or one of each. One of the
most well known snips is for eye color. Around 5,000 years ago, the snip
for blue eyes developed and quickly spread throughout European population.
If you have blue or light green eyes, you likely have two of the derived
copies. If you have brown eyes, you likely have either one or two copies of
the ancestral version.
These snips have a location on one of your chromosomes. If you share 700 or
more of these snips in a row with another member in the database,
statistically you must have both inherited that section of your dna from a
common ancestor. The longer the segments and the more segments that you
share with someone the closer the relationship. In general, a child shares
50% with their parents and siblings, 25% with their grandparents, aunts,
uncles, 12.5% with first cousins, 3% - 6% with second cousins, 1% - 3% with
third and fourth cousins, and less than 1% with 5th cousins and beyond.
For my Father-in-law, who is Volhynian German on both sides, he has 1,000+
matches. Of them, about 50 are either larger or multiple segments, and it
is these that I focus my genealogy efforts on. His highest match (outside
of our known family), is another German from Volhynia with whom he shares
1.58% and 6 segments, who is predicted to be his third cousin. As they
shared a family name, it was fairly easy to determine where the common
ancestry was. Otto, his son, and cousin also show up as matches at the
predicted 4th cousin level, but we have yet to discover the exact nature of
the common ancestry.
Which service you use is a matter of personal preference. 23andme has the
largest database, but many of the participants tested for health reasons and
are not interested in genealogy. FTDNA and Ancestry are newer and have
smaller databases, although if you match someone there they are more likely
to be interested and have a family tree to share with you. A free service
called gedmatch, allows you to upload results and compare them to others,
including those who have tested using another service.
I am a huge fan of dna testing, having tested a large portion of my family,
including my infant son and my 90 year old late father. I use the results
for both health and ancestry. For those who have elderly family members, I
would encourage you to have them tested while they are still with us. The
technology is evolving rapidly and as more people test, it will become
easier to find ancestors from the results.
From: Ger-Poland-Volhynia [mailto:ger-poland-volhynia-bounces at sggee.org] On
Behalf Of Otto
Sent: Friday, September 13, 2013 10:58 AM
To: ger-poland-volhynia at sggee.org
Subject: Re: [Ger-Poland-Volhynia] DNA Testing Explained
On Sep 12, 2013, at 6:45 PM, Gary Warner wrote:
> I am told that all of the major companies (23andME, myFTDNA, and Ancestry)
all use the same protocol to test the spit for the Autosomal test. If that
is the case, then the only big issue is that being in one database does not
also place you in the databases of the other two. Not sure if they all also
use the same protocols for the Y-DNA and mtDNA.
> Gary Warner
Good morning Gary and Listers,
I do know the 23andme uses Illumina labs for the 1,000,000 marker test.
My code results are in 23andMe's databank on their encrypted website.
Only I have direct access to my code (password protected).
I can, and have, downloaded a copy of all my DNA code to to my computer and
archived it for preservation for the future.
21 chromosome pairs, X chromosome, Y chromosome and the MT code.
The best part of 23andMe, and I mean best, (I personally consider the
spit-test a freebie) is their encrypted website for password members. A
one-time fee (test included) of $99.00 for continuing access to it and all
of the tools and information. (yes. I've checked out the 'others') For
Browse Raw data-My Profile (with hot-links to all of the other Public
profiles)-Manage My Profile-Settings-Inbox for e-mail Health Overview-Health
Risks, Drug response, Inherited Conditions, Traits, Health Tools Ancestry
Overview-Ancestry Composition, Materna Line, Paternal Line, Neanderthal
Ancestry, Ancestry Tools
Research and Community:
I cannot give answer to your opinions, conjectures, without sufficient
evidence or proof. Read your words, 'I am told', 'if that is the case',
'only big issue', 'not sure if' leave me with only a hypothetical surmise.
Macht ja aber nichts. . .
Without 23andMe's website as the focal point for comparison and
communication, the test code is useless to me.
. . . Otto
" The Zen moment..." wk. of January 01, 2013-
"Answers out there . . . Seeking us."
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