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Pizza and… Who do you think you are?
an overview of one of the newest and possibly more helpful developments in researching genealogy and
family history – that of using DNA for research
What is DNA? Part 1
• It is DeoxyriboNucleic Acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
What is DNA? Part 2
• A genealogical DNA test looks at a person's genome (A genome is an organism's complete set of DNA, including all of its genes at specific locations). Results give information about genealogy or personal ancestry. In general, these tests compare the results of an individual to others from the same lineage or to current and historic ethnic groups.
So, I can spit in a tube and get my whole family history, right?
• If you have a patron who comes up and says this, here’s what you should explain.
• No, you can’t.
• Here’s where you can find out more.
• Here are the main companies that do the testing.
What companies can do this?
• Ancestry.com,
• Family Tree DNA,
• and 23 and Me
---problem is, they do not talk to one another, and public free databases like GEDMATCH are not used. Do you go with the company with the largest database or the best testing?
BASIC DNA TERMS
• Allele / Gene
• Bases
– A – Adenine
– T – Thymine
– C – Cytosine
– G - Guanine
• Chromosomes
• DNA
• Genome
• Locus/marker
• Haplogroup
• Haplotype
• MRCA
• Phylo-tree
• SNP
• STR
• Sub-clade
GENETIC TERMS
Useful Terminology
Used with permission from Shannon
Combs-Bennett (c) 2014
Last boring picture of DNA…
What are some common mistakes?
Believing that DNA will fill in your family tree.
I don’t have an ancestor’s DNA. They are dead.
I don’t like needles!
I am female. How do I test for male DNA?
The DNA will reveal medical problems.
• It is the DNA you inherit through autosomal chromosomes, not through the sex determining chromosomes.
What is Autosomal DNA
An autosome is any of the numbered chromosomes, as opposed to the sex
chromosomes. Autosomal DNA tests can be used to confirm relationships
with a high level of accuracy for parent/child relationships and all
relationships up to the second cousin level.
• Tersely, it is the chromosome that determines maleness, and is passed from father to son.
What is Y-DNA
Results For Men
• Y-DNA results can be used to verify the male lineage
Y-DNA Results
Since men do not get a Y chromosome from their mothers,
a paternal line can be traced
• mtDNA is passed from a mother to all of her children
• mt = Mitochondira
What is mtDNA
mT Dna has only women
Results For Women
Tersely put
From Blaine Bettinger -
Talk about diminishing returns…
Wait…What Just Happened?
Image from ricochetscience.com
Parents
Children
Grandchildren
Great grandchildren
Example Result: FTDNA Chromosome Comparison
This is mine from FT DNA
This is a sample from FT DNA
Orange = Mom
Blue = Mom's brother
Shannon Combs-Bennett (c) 2014
Example Results: FTDNA
Reconstructed
Sapiens
Reference
System
Example Results: FTDNA
My own results
From my own AncestryDNA
A sample tree from my DNA match “cousin”.
My guys 2nd marriage
• “Most of my distant relatives have their kits at Ancestry.com - which has much faster growing database - but I prefer FamilyTreeDNA for the better analysis tools.” and someone else wrote:
• “My entire project plan is about using FTDNA tools in conjunction with GedMatch. I sure hope that this GedMatch issue is temporary.”
Unhappy campers
• 23andme just shot themselves in the foot with their price increase. Leaving ancestry and ftdna as the top dna contenders.
• “ I have the ‘DNA’ results from about 5 yrs ago. This shows me nothing. There is no map There is a page that shows numbers but the explanation is worthless and meaningless I paid for both DNA test and membership and WOW did I get ripped off”
From GEDMATCH.com:
• “We regret we had to make the decision to stop accepting FTDNA [FamilyTreeDNA.com] DNA uploads. FTDNA has threatened to sue GEDmatch over claimed privacy issues. We have been asked not to discuss the details, because it would be to FTDNA’s disadvantage. Suffice it to say that FTDNA’s own site seems to currently violate these same issues.
Haplogroup Migration Map
An ad from 23andMe
From My Heritage:
• Here are some of our price reductions during this special DNA sale:
• mtDNAPlus: Was $129 Now only $59←maternal line
• Powerful combo for male customers only:
• Buy Y-DNA37 + mtFullSequence, get Family Finder free
• Was $307 Now only $248← best value for all lines.
• Y-DNA111: Was $359 Now only $299←highest resolution test on the paternal line.
• You won’t have to give blood..
• You can use your own DNA via a saliva tube.
• It can help confirm – or refute! – your research.
• You might find more family links
Some valid concerns
• Will insurance companies see the results?
• NPE’s (adoptions, illegitimacies)
• What about law enforcement? Maybe…
• “Your Relative’s DNA Could Turn You Into a Suspect” from WIRED.com
What do you think about this?
A single gram of DNA can store 1 trillion gigabytes and last for 2,000 years.
centimorgans
• If you have 10 centimorgans in common with another person, there is a 99 percent chance that you are related (and just by sheer chance).
• FT DNA can accept Ancestry data
• But if you do another test it could very well give you a different result!
• Tree can be blocked from view
Centimorgans…
• are measurements of how likely the segment is to recombine as it passes from parent to child. Segments with higher cM values have a greater probability of recombining in any one generation. Therefore, when you share DNA segments with larger cM values with a match, your common ancestors are likely to come from generations that are more recent.
• For example, known second cousins on average share 212.5 centiMorgans (cMs), but in extreme cases can actually share as little as 47cMs or as much as 760cMs. Conversely, the relationship between pairs of individuals sharing 212.5cMs has been found to be anywhere between aunt-or-uncle/niece-or-nephew and third cousin once removed
• Autosomal DNA is inherited equally from both parents. The amount of autosomal DNA inherited from more distant ancestors is randomly shuffled up in a process called recombination and the percentage of autosomal DNA coming from each ancestor is diluted with each new generation.
• When interpreting autosomal DNA statistics, one must be careful to distinguish between the distribution of shared DNA for given relationships and the distribution of relationships for given amounts of shared DNA.
• For example, known second cousins on average share 212.5 centiMorgans (cMs), but in extreme cases can actually share as little as 47cMs or as much as 760cMs. Conversely, the relationship between pairs of individuals sharing 212.5cMs has been found to be anywhere between aunt-or-uncle/niece-or-nephew and third cousin once removed.
• Autosomal DNA is inherited equally from both parents. The amount of autosomal DNA inherited from more distant ancestors is randomly shuffled up in a process called recombination and the percentage of autosomal DNA coming from each ancestor is diluted with each new generation.
• For example, known second cousins on average share 212.5 centiMorgans (cMs), but in extreme cases can actually share as little as 47cMs or as much as 760cMs. Conversely, the relationship between pairs of individuals sharing 212.5cMs has been found to be anywhere between aunt-or-uncle/niece-or-nephew and third cousin once removed.
Where can I find out more?
• Blaine Bettinger has a blog:
• http://thegeneticgenealogist.com/
• And also http://www.cyndislist.com/dna/
From the RGS’s February speaker:
For the very first
time, GGP offers
hands-on exercises
in areas of Y-DNA,
mtDNA, X-DNA,
atDNA, the
Genealogical Proof
Standard, ethics,
and more.
DNA evidence is increasingly necessary to confirm even the most documented and researched pedigrees. DNA evidence can also help examine some genealogical questions that appear nearly hopeless with traditional genealogical research.
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