What I discovered about my own family tree when I charted my DNA matches from Ancestry.

1. DNA Evidence
Using DNA to Verify My Ancestry Tree
Jamie Cox
January, 2016

2. My Background
• Using Ancestry for ~ 4 years
• 1130 People on my tree
• Mostly in Georgia, USA
• I’ve Taken the Ancestry DNA test
• Which of my research lines have DNA evidence?

3. Data Overload
• 254 Pages of matches
• (Over 1200 matches)
• Two 2nd cousin matches
• Eight 3rd cousin matches
• 60 DNA Hints
• 620 4th-6th cousin matches
• 19 DNA Circles
• (I have No “New Ancestor Discovery” Circles)

4. Back to Basics
• What areas of my family tree are solidly backed by
DNA evidence?
• I have a lot of DNA matches that don’t match my tree
• Are any areas wrong?
• How to use all this data?
• Ancestry provides very limited tools
• I Decided to make a paper chart

5. Fan Chart

6. Grandparents

7. Great-Grandparents

8. GG Grandparents

9. 3rd GGrandparents

10. Mother’s Tree
Brick Wall

11. Father’s Tree

13. DNA Circle

14. DNA Circle
DNA Hint

15. DNA Circle
DNA Hint
Wow!
No Matches
to Paternal Grandfather’s
Tree. Uh-Oh.

16. Chart Interpretations
Absence of evidence is not evidence of absence
• Am I the Last of the Mohicans?
• What if I’m one of the only living descendants from this
family, and there’s no one else to match … or…
• My paternal grandfather’s folks don’t like genealogy/DNA
• Unlucky DNA - My DNA happens to differ so much as to
not be a match
• Non-paternity

17. The Fourth Case
DNA Match No DNA Match
Trees Match
DNA Hint or
Circle
Mismatch Alert!
X
No Tree Match
“New Ancestor
Circle” or regular
DNA match
unrelated,
ignore

18. Non-Paternity
Non-paternity - anytime someone’s actual parent(s)
are not who we think they are
• Non-Paternity Events:
• Infidelity
• Rape
• Secret Adoption - a woman pretends a child is
hers to protect the actual mother

19. Non-Paternity Rate
Generation
Opportunities
for Error
Total
Opportunities
for Error
1.2% 1.5% 5.0%
Years
Ago
You 0 0 0 0% 0% 0% 0
Parents 1 1 1 1% 2% 5% 20
Grandparents 2 2 3 4% 4% 14% 40
GG parents 3 4 7 8% 10% 30% 60
GGG parents 4 8 15 17% 20% 54% 80
GGGGp 5 16 31 31% 37% 80% 100
… 6 32 63 53% 61% 96% 120
7 64 127 78% 85% 100% 140
8 128 255 95% 98% 100% 160

20. Next Steps
• Test Family Members’ DNA
• Father (deceased)
• Mother ✔(Helps identify matches as maternal/paternal)
• Siblings ✔(Complete, another random sample of Dad’s DNA, similar results)
• 2nd or 3rd cousins ✔
• I’m looking for “cousins” who may not be cousins
• Cousins on my tree who have done DNA test (Found 4!)
• They don’t match my DNA - non-paternity confirmed
• Y-DNA Testing ✔ - since my straight male line is now in question
• NO matches to my surname

21. Help From ancestry.com
• We need help with all this data, please
• Ancestry should have drawn that DNA chart for me
• need WAY more searching & sorting options
• User-assignable tags & categories
• AND/OR/NOT filters
• Download DNA matches to spreadsheet