DNA Newbie FAQ

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Table of Contents

TERMINOLOGY 2

I thought this was a newbies list but the discussions are way over my head? 2

Where can I find definitions of terms like SNP, base pairs, etc? 2

What is the difference between a STR and a SNP? 2

TESTING 3

What are the the different DNA tests and why should I try one? 3

Where should I test? 3

Is there a more economical way to ship from abroad? 4

Whom should I test? 4

I am adopted. Where can I go to get some help? 4

TUTORIALS and CLASSES 4

Genetic Genealogy Overviews 4

Genetic Genealogy Classes 4

23andme.com 5

Ancestry.com 5

FamilyTreeDNA.com 5

DNA Relatives 5

How much DNA do I expect share with a sibling, half sibling, parent, aunt, 1st/2nd/3rd cousin? 5

My testing company shows us as 2nd-4th cousins but we cannot find a recent common ancestor? 5

Looking for that MRCA: Is there are automated way to compare GEDcoms? 6

MATCHES 6

I have seen people say they do not bother with one segment matches smaller than 10cM, why is that? 6

I have a one segment match of ??cM, how recently are we related? 6

I have a ??cM match on the X chromosome, is that significant? 6

Does anyone have some good examples of contact letters to share? 7

ANCESTORS 7

My ancestry is half XYZ and half ABC yet my ancestry composition is showing only a little of each of those and lots of PQR? 7

How many ancestors do I get my DNA from? 7

How useful is the “GPS” tool to tell me what village my ancestors came from? 7

MORE … 8

What are some of the tools and methodologies to use for genetic genealogy? 8

Where can I find out what our shared DNA means in terms of shared traits or problems? 8

Where is there a more advanced mailing list about DNA? 8

Are there standards for Genetic Genealogy? 9

Are there conferences for just genetic genealogy? 9

TERMINOLOGY

I thought this was a newbies list but the discussions are way over my head?

It is impossible to discuss genetic genealogy without using terms specific to this field. Kelly Wheaton has put together a wonderful lesson series for newbies that should help you learn the language and more importantly clarify many of the concepts:

https://sites.google.com/site/wheatonsurname/beginners-guide-to-genetic-genealogy

More classes and tutorials are listed below.

There is also a new book out that is a great help: Genetic Genealogy: The Basics and Beyond by Emily Aulicino.

Is there an acronym or abbreviation list somewhere?

The ISOGG wiki has this list

http://www.isogg.org/wiki/Abbreviations

The DNA Adoption website has this list

http://dnaadoption.com/index.php?page=glossary-of-dna-terms

Where can I find definitions of terms like SNP, base pairs, etc?

The ISOGG wiki has detailed explanations of all these terms.

http://www.isogg.org/wiki/Wiki_Welcome_Page

The DNA Adoption website has this glossary

http://dnaadoption.com/index.php?page=glossary-of-dna-terms

For a more in depth understanding try Kelly Wheaton’s lessons on autosomal DNA

https://sites.google.com/site/wheatonsurname/beginners-guide-to-genetic-genealogy/lesson-5-introduction-to-atdna

What is the difference between a STR and a SNP?

 

Roberta Estes explains this very well in her blog article on that subject:

http://dna-explained.com/2014/02/10/strs-vs-snps-multiple-dna-personalities/

TESTING

What are the the different DNA tests and why should I try one?

To learn more about DNA testing I recommend you read these articles by Cece Moore at geni.com:

Part One, Y-DNA: http://www.geni.com/blog/dna-testing-for-genealogy-getting-started-part-one-375984.html

Part Two, mtDNA: http://www.geni.com/blog/dna-testing-for-genealogy-getting-started-part-two-376163.html

Part Three, autosomal DNA: http://www.geni.com/blog/dna-testing-for-genealogy-getting-started-part-three-376261.html

Part Four, ancestral origin tests and summary: http://www.geni.com/blog/dna-testing-for-genealogy-getting-started-part-four-376433.html

Where should I test?

This depends on your goals and your budget. ISOGG has a comparison chart of the testing companies here: http://www.isogg.org/wiki/Autosomal_DNA_testing_comparison_chart

The latest big news is that ancestry.com tests can be transferred to Family Tree DNA for free (limited account) or as little as $39. A number of people have blogged about this including me:

http://blog.kittycooper.com/2014/10/free-transfer-of-dna-data-from-ancestry-to-family-tree-dna/

This makes me recommend testing at ancestry and then transfering to Family Tree DNA and Gedmatch. Do 23andme as well if your budget allows this.

My personal thoughts on where to test are as follows. If you are interested the health issues (disabled but you can upload elsewhere for those) and/or want the best ancestry composition then test at 23andme. If you are adopted or have Jewish ancestry, either use Ancestry.com and then transfer to Family Tree DNA or start with the family finder test at familytreeDNA.com. If you have colonial ancestry the best database may be at ancestry.com (USA only) but they have the fewest tools for comparing DNA, however those results can be transferred to FamilyTreeDNA for a tiny fee. Wherever you test, upload your results to GEDmatch.com for the best ancestry composition tools and to compare with testers from other companies

Note that if you are searching for a specific surname a Y test at familytreeDNA.com might make more sense. If your puzzle is on the maternal line then their mtDNA test may be what you want. If you are interested in your deep ancestry then either Britain’s DNA or the Genome 2.0 test at National Geographic may have your answers.

Read this for more thoughts on which DNA test to do:

https://sites.google.com/site/wheatonsurname/beginners-guide-to-genetic-genealogy/lesson-two-which-dna-test

ISOGG has pages on the other tests also:

http://www.isogg.org/wiki/MtDNA_testing_comparison_chart

http://www.isogg.org/wiki/Y-DNA_SNP_testing_chart

http://www.isogg.org/wiki/Y-DNA_STR_testing_chart

Is there a more economical way to ship from abroad?

ISOGG has a page on shipping DNA kits which includes details of package forwarders that some ISOGG members have used to order a DNA test kit and bypass the country restrictions and/or the excessive courier charges:

http://www.isogg.org/wiki/Shipping_DNA_kits

Whom should I test?

As many relatives as you can talk into doing it! Best to get the oldest generation tested now while they are still here and also their genes are closest to your ancestors. But again, it depends on your goals. Personally I have found 2nd cousins to be very useful for isolating matches to a specific family line.

I am adopted. Where can I go to get some help?

 

You can go to http://www.dnaadoption.com and learn more about using DNA for adoptees. In addition, there is a DNA group specific to adoptees at http://groups.yahoo.com/neo/groups/dnaadoption/info . Finally, there is a group of Search Angels willing to help you out with your basic Adoption search. Find out more at http://groups.yahoo.com/neo/groups/SoaringAngels/info

TUTORIALS and CLASSES

Genetic Genealogy Overviews

Good overview of genetics and genealogy by Stephen Morse:

http://stevemorse.org/genetealogy/beyond.htm

Kitty’s basics page

http://blog.kittycooper.com/dna-testing/dna-basics/

Genetic Genealogy Classes

The videos from the recent IS4G conference are online now and very reasonably priced

http://i4gg.org/pricing/

From ISOGG in 2005

http://www.isogg.org/course/intro.htm

more recently

from Kelly Wheaton

https://sites.google.com/site/wheatonsurname/beginners-guide-to-genetic-genealogy

The National Genealogical Society has a for pay course but have no reviews of it

http://www.ngsgenealogy.org/cs/genetic_genealogy

Coursera.org has two free courses on DNA which get technical very quickly but early lessons may be of use:

https://www.coursera.org/course/usefulgenetics

https://www.coursera.org/course/geneticsevolution

23andme.com

http://blog.kittycooper.com/2013/04/the-basics-at-23andme/

and this Utube video with Cece’s presentation

https://www.youtube.com/watch?v=kCJr7t2Sbpg#t=10

Ancestry.com

http://blogs.ancestry.com/ancestry/2012/10/22/youve-received-your-ancestrydna-results-now-what/

FamilyTreeDNA.com

http://www.isogg.org/wiki/Family_Finder

and some links with more up to date screen shots here:

http://blog.kittycooper.com/dna-testing/family-tree-dna-basics/

and some webinars from Family Tree DNA

https://www.familytreedna.com/learn/ftdna/webinars/

DNA Relatives

How much DNA do I expect share with a sibling, half sibling, parent, aunt, 1st/2nd/3rd cousin?

See this article for the percentages:

http://www.isogg.org/wiki/Autosomal_DNA_statistics

and this one for the expected number of cMs and segments

http://www.isogg.org/wiki/IBD#Ranges_of_total_centimorgans_of_IBD_segments_expected.2C_based_on_family_relationship

My testing company shows us as 2nd-4th cousins but we cannot find a recent common ancestor?

Most likely you have more than one common ancestor which makes your relationship look closer than it is. If you come from a very endogenous population such as Ashkenazim or Mennonite then all your relationships will look closer than they are

GEDmatch has a tool for looking at your data to see how likely it is that your parents are related

http://gedmatch.com/

David Pike has a number of tools also for looking at your raw data

http://www.math.mun.ca/~dapike/FF23utils/

By the way, the abbreviation MRCA is used for “Most Recent Common Ancestor.”

Looking for that MRCA: Is there are automated way to compare GEDcoms?

Kitty did a blog post on that subject:

http://blog.kittycooper.com/2013/12/finding-common-ancestors-with-automation-compare-gedcoms-or-use-a-one-world-tree

MATCHES

I have seen people say they do not bother with one segment matches smaller than 10cM, why is that?

With smaller segments it becomes a matter of percentages. Where

IBS = Identical By State = by chance

IBD = Identical By Descent = inherited

(per analysis by John Walden)

(see http://dna-footprints.com/203/the-abcs-of-dna-ibd-vs-ibs/ for good explanations of these terms)

11 cM or greater matching segment: >99% IBD, <1% IBS

10 cM matching segment: 99% IBD, 1% IBS

9 cM matching segment: 80% IBD, 20% IBS

8 cM matching segment: 50% IBD, 50% IBS

7 cM matching segment: 30% IBD, 70% IBS

6 cM matching segment: 20% IBD, 80% IBS

5 cM matching segment: 5% IBD, 95% IBS

4 cM matching segment: ca 1% IBD, ca 99% IBS

An Ashkenazi cousin claims that it is not worth bothering with matches of less than 23cM in that population group

I have a one segment match of ??cM, how recently are we related?

You can be anywhere from 4th to 14th cousins. See this article

http://ongenetics.blogspot.com/2011/02/genetic-genealogy-and-single-segment.html?m=1

I have a ??cM match on the X chromosome, is that significant?

Maybe. The X chromosome can reach farther back in time than the other autosomes. The approximation I have heard is that the X recombines at about 2/3 the rate of the other chromosomes. Since X chromosome matching was added to Family Tree DNA ,there have been many questions and good blog posts on the subject.

 

The lists below are taken from Kitty’s post What does shared X DNA really mean?

Here are some of the better explanations of X inheritance inheritance and helpful charts:

Here are some of the blog posts discussing how to use the new X matching feature at familyTreeDNA:

 

Does anyone have some good examples of contact letters to share?

Please send them in, someone on the list once posted this terrific introduction he uses in his.

“I would like to share genomes at a basic level (no health reporting, only shows where we match on our chromosomes) to see where we overlap and perhaps find our common ancestors.”

ANCESTORS

My ancestry is half XYZ and half ABC yet my ancestry composition is showing only a little of each of those and lots of PQR?

None of the testing companies have completely accurate predictions. 23andme is the best of the lot. All are dependent on who has tested from which countries. If your population group is not well represented then no predictions are going to be all that accurate. Plus there was plenty of population movement hundreds of years back that you may not be aware of.

Try uploading to GEDmatch.com and using their admixture tools. Plus read this detailed blog entry from Roberta Estes on that issue:

http://dna-explained.com/2013/10/04/ethnicity-results-true-or-not/

How many ancestors do I get my DNA from?

About 120 from the last 10-12 generations. See this article for the details

http://www.genetic-inference.co.uk/blog/2009/11/how-many-ancestors-share-our-dna/

How useful is the “GPS” tool to tell me what village my ancestors came from?

Probably not useful unless all your ancestors are from one country. Read what Debbie Kennett says:

http://cruwys.blogspot.com/2014/05/driving-in-wrong-direction-with-dodgy.html

and another more detailed and disappointed blog post from someone who tried it:

http://olivetreegenealogy.blogspot.com/2014/05/prosapia-genetics-worth-money.html

MORE …

What are some of the tools and methodologies to use for genetic genealogy?

The ISOGG wiki has pages listing autosomal DNA tools, Y-DNA tools and mtDNA tools:

Autosomal tools: http://www.isogg.org/wiki/Autosomal_DNA_tools

Y DNA tools: http://www.isogg.org/wiki/Y-DNA_tools

mtDNA tools: http://www.isogg.org/wiki/MtDNA_tools

Kelly Wheaton has a good list of tools here:

https://sites.google.com/site/wheatonsurname/beginners-guide-to-genetic-genealogy/lesson-11-not-reinventing-the-wheel

 

and the author of this FAQ, Kitty Cooper has a list of her tools and her other favorite tools here: http://blog.kittycooper.com/tools/

 

ISOGG has an entry with many links about chromosome mapping here: http://www.isogg.org/wiki/Chromosome_mapping

which include links to Tim Jantzen’s methodology

 

Roberta Estes does a very good job of explaining the chromosome mapping technique in this blog post:

http://dna-explained.com/2013/12/09/chromosome-mapping-aka-ancestor-mapping/

Where can I find out what our shared DNA means in terms of shared traits or problems?

The National Library of Medicine has a chromosome by chromosome resource. Of course most genetic research has concentrated on diseases and problems not traits.

http://ghr.nlm.nih.gov/chromosomes

UCSC has a Genome Browser website. This site contains the reference sequence and working draft assemblies for a large collection of genomes. It also provides portals to the ENCODE and Neandertal projects. Located at http://genome.ucsc.edu/

23andme’s one to one comparison does show some traits (under family and friends, gene comparison)

Where is there a more advanced mailing list about DNA?

 

When you are no longer a newbie feel free to stay and help. However you may pose your more advanced questions on the rootsweb list for DNA and genealogy or the one for autosomal DNA:

http://lists.rootsweb.ancestry.com/index/other/DNA/GENEALOGY-DNA.html or

http://lists.rootsweb.ancestry.com/index/other/DNA/AUTOSOMAL-DNA.html

 

Are there standards for Genetic Genealogy?

There is an in-progess standards document published here:

https://sites.google.com/site/geneticgenealogystandard/

That document is intended to provide ethical and usage standards for the genealogical community to follow when purchasing, recommending, sharing, or writing about the results of DNA testing for ancestry.

Are there conferences for just genetic genealogy?

Yes but none in the near future. Rootstech in February always has some good genetic genealogy lectures

https://rootstech.org/?lang=eng

Many of the lectures from the Who Do You Think You Are 2014 a recent conference in the UK are available on youtube at

https://www.youtube.com/channel/UC7HQSiSkiy7ujlkgQER1FYw?feature=watch

And many of the lectures from the recent conference in Ireland are at YouTube as well

https://www.youtube.com/channel/UCHnW2NAfPIA2KUipZ_PlUlw

and see the classes section above for the link to the videos from the recent I4GG conference

 

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