DNA, Ancestry, and Your Genealogical Research Walter Steets Houston Genealogical Forum DNA Interest Group March 2, 2019 1
Today s Agenda Brief review of basic genetics and terms used in genetic genealogy DNA Chromosomes Genetic genealogy metrics i.e. What s a centimorgan? The New Ancestry s Strategies for Discovering Relationships with DNA Sorting out your DNA matches ThruLines genealogy and genetics come together Group Discussion
Chromosomes How many chromosomes do people have? Each human cell normally contains 23 pairs of chromosomes for a total of 46 22 pairs are the same in men and women and are called autosomes 23 rd pair are the sex chromosomes Men have an X and Y chromosome Women have two X chromosomes Each chromosome pair contains one chromosome from each parent Autosomal DNA (atdna) tests are offered by all the testing companies including Ancestry Y-DNA tests are only available from FamilyTreeDNA 3
Identifying DNA Segments DNA two chains of repeating lengths of smaller molecules known as nucleotides that coil around each other to form a double helix. Chromosome A strand of DNA which carries genetic information in the sequence of its nucleotide base pairs Adenine and Thymine A-T Cytosine and Guanine C-G 99.9% of DNA in humans is identical SNP Single Nucleotide Polymorphism Difference of a single nucleotide between DNA strands of several thousand nucleotides which are otherwise identical. Genetic DNA tests measure about 700,000 SNPs. Segments - Differences in DNA are identified by patterns of hundreds or thousands of SNPs. These patterns of SNPs are used to identify DNA segments. DNA Base Pairs Adenine Thymine Cytosine Guanine G-C T-A DNA Segment on chromosome 1 for Person A SNP 1 Identical sequences of several thousand base pairs SNP 2 A-T A-T DNA Segment on chromosome 1 for Person B 4
Chromosomes Mega Base Pairs Physical distance along a chromosome is measure in millions of base pairs referred to as Mb. centimorgans Different sections of the chromosome are more likely than others to change when child DNA is formed. DNA sections which have the same probability of changing are measured in cm for centimorgans. Segments SNPs markers identify DNA segments. The start and end of segments are specified in Mb. The length of segments are given in cm. (Centimorgans cm ) Segments Segment Map identified by SNP markers (mega base pairs Mb ) Adapted from NHGRI Fact Sheets Genome.gov 5
Each box (male) and circle (female) represents one chromosome pair for the named person. Due to crossing over, offspring inherit recombinant chromosomes of their parents. The first cousins in the bottom row, Karen and Louis, share one IBD segment. Both have inherited this IBD segment from the same individual, their grandfather Carl (orange colored chromosome in the top row). Carl and Donna are the MRCA for Karen and Louis Segments which are Identical by Descent (IBD): Example of 1 st Cousins Albert Bertha Carl Donna Edward Fiona Gregory Helen Ian Janice Karen Adapted from Gklambauer, Wikimedia Commons Louis Most Recent Common Ancestors MRCA 6
Degree of Separation Degree of separation: measures the genealogical and genetic distance between two people on separate lines of a Most Recent Common Ancestor (MRCA) descendant tree. Genealogically the degree of separation is the number of ancestors and descendants between the two people on a descendant tree Genetically the degree of separation equals the number of DNA transfers between two people. The larger the degree of separation between two people, the less DNA they will share. For degrees of separation larger than about 10-12, descendants are likely not to share any DNA. Most Recent Common Ancestor MRCA 7
Ancestry DNA Match Category Ancestry Possible Range Ancestr y s DNA Match Categories Degrees of Separation Most Likely (Range) Relationships Parent/Child 1 Parent or child Immediate Family 2 Full sibling Close Family Close family 1 st cousin 3 (2 4) 1 st Cousin 1 st 2 nd cousin 4 (3 5) 2 nd Cousin 1 st 2 nd cousin 5 (4 7) 2 nd Cousin 2 nd 3 rd cousin 6 (5 7) 3 rd Cousin 3 rd 4 th cousin 7 (6 9) 4 th Cousin 4 th 6 th cousin 8 (4 12) Aunt, uncle, niece, nephew, grandparent, grandchild, halfsibling 1C, great-grandparent/children, greataunt/uncle/niece/nephew, half-aunts/uncles/niece 1C1R, half-1c, 2C, 2 nd great grandparent/grandchild 2C, 1C2R, half-1c1r 2C, 3C, half-2c, 2C1R, 2C2R, 1C2R, 1C3R, 3C1R 2C and more distant From Ancetry DNA-Match-Relationships
Ancestr y Genealogy Ancestry Hints 100 Million Pedigree Trees ThruLines 20 Billion Records 15 Million DNA kits Ethnicity Estimate 9
Ancestry s Strategy for Uncovering DNA Match Relationships 1. Take an Ancestry DNA test. 2. Create a tree on Ancestry. 3. Make the tree public. 4. Link your DNA to your tree. 5. Review your DNA Matches using the Search box to find your family surnames. 1. Create Groups to identify where your Matches fit in your family tree. 6. Link your DNA to your tree (in case you missed step 4). 7. Use ThruLines to find Matches who descend from your ancestors MRCA s 8. Follow-up on new clues: 1. Research Matches trees and sources 2. Send Ancestry Messages to Matches offering to exchange information about shared ancestors 10
DNA Results Summary Page Link to Tree Click one of the Links to Tree (circled in red) 11
Allows you to see how you re related to your DNA matches - necessary for ThruLines Information about living people in your family tree is protected. You can only link your DNA results to a family tree that is associated with your Ancestry account. Tree of a person who has Ancestry manage permission on DNA test taker s account - preferred for managed accounts Tree of DNA test taker Linking your DNA results to a public family tree is the best way to connect with others. Linking DNA with a Tree 12
Ancestr y Pedigree Trees Ancestry DNA testers who are not Ancestry Subscribers and can post a tree but not view other people s trees. Tree should contain basic genealogical data Name, gender, birth date and place Parents, spouse for each person in tree Minimum 4 generations : great grandparents MRCA for 3 rd cousins 5 generations are better: 2 nd great grandparents MRCA for 4 th cousins Loading tree data Use an existing Ancestry tree in which tester is identified Upload a GEDCOM file Manually 13
Linking DNA with a Tree Choose the tree which contains the DNA test taker Choose the person in the selected tree who is the DNA test taker Click Link to Tree 14
Updates Ancestr ydna Home Page Testers with Linked Trees Major Changes New 15
Ancestr y Lab New Ancestry features which are optional for the user during Ancestry s testing period can be activated in Ancestry Lab Click on Extras in the main menu Click on Ancestry Lab in the drop-down menu 16
New Features in Ancestry Lab New DNA Matches Enable turns on the new format for all kits you view including ones you manage Chrome extensions including MedBetter DNA will not work. Information which had been saved in Notes is now shown by Ancestry. 17
Ancestr y Matches 18
New Ancestr y Matches Page New Features Filters Group Filter by Add to group Changed Features Display format Notes: now displayed without Matches scroll continuously, not by page 19
Search for Matches in Matches Trees Good first step in ancestor search strategy Only searches in Matches linked trees, not in unlinked trees Finds Search name in Private people in trees 20
Group Filter by fixed groups of Matches Create new groups and filter on those Add Matches to groups New Matches Features: Group Create custom group Create a Group Name Choice of 24 colors 21
New Matches Features: Filter by Filter by Filter by fixed groups of characteristics of Marches Filter on whether a Match has a Note, not on contents of Note Group and Filter by can be used together to reduce size of Match list. 22
ThruLines 23
ThruLines: Start with an Ancestor, not a Match Shows ancestors on cards Shows ancestors based on linked tree Two types of ancestors: Only shows direct ancestors, not other people included in the tree Ancestors from your Linked Tree - people shown as your direct ancestors in your Linked tree. Potential Ancestors People from your Matches trees who may be your MRCA with your Matches You can show cards for only one type of ancestor or both types together Ancestry has not yet published a white paper on ThruLines so we don t know some details about their selection process. 24
Case Study: Monica s Maternal Pedigree Chart Research John Lindsay and his ancestors Samuel Lindsay b. Abt. 1825 Ireland Elizabeth St. Ledger b. Abt. 1825 England John Lardner Abt. 1825 Ireland Honor Walsh b. Abt. 1822 Ireland John Howarth b. Abt. 1814 Austria John Deresweiler Catherine Marta John Lindsay b. Jun 1850 Ireland Margaret Lardner b. Oct. 1860 Ireland Joseph Howarth b. Mar. 1846 Austria Christina Deresweiler b. Jul 1858 Dusseldorf, Germany George Lindsay b. Jan. 1891 Council Bluffs, Iowa Josephine Howarth Mar. 1896 Council Bluffs, IA Patricia Lindsay b. Aug. 1922 Council Bluffs, IA Monica b. Council Bluffs, IA 25
Research John Lindsay Ancestor cards on the ThruLines screen are arranged in the order of genealogical distance from tester Father Mother Paternal grandfather Paternal grandmother Relations are shown underneath the name on the cards Apparently in ahnentafel number order Select the card for John Robert Lindsay. Maternal grandfather Paternal grandmother Paternal GGF Paternal GGM Paternal GGF 2 Paternal GGM 2 Maternal GGF Maternal GGM 26
ThruLines for John Lindsay DNA Matches with John Lindsay as the MRCA 27
ThruLines: Descendants of John Lindsay The Ancestry trees for Monica, Christinecread, and athompsonbusch show John Robert Lindsay and his descendants. The Ancestry tree for MolodyBanisterBarch only shows her mother. In this case, ThruLines determined the proper relationships from these trees and the DNA matches. John Lindsay is the MRCA for Monica and Margarent with each of these DNA matches 28
Ancestr y s DNA Strateg y for Researching Ancestors (Review) 1. Take an Ancestry DNA test. 2. Create a tree on Ancestry. 3. Make the tree public. 4. Link your DNA to your tree. 5. Review your DNA Matches using the Search box to find your family surnames. 1. Create Groups to identify where your Matches fit in your family tree. 6. Link your DNA to your tree (in case you missed step 4). 7. Use ThruLines to find Matches who descend from your ancestors MRCA s 8. Follow-up on new clues: 1. Research Matches trees and sources 2. Send Ancestry Messages to Matches offering to exchange information about shared ancestors 29
Appendices Additional slides with more detailed information follow. These probably require more explanation than is provided on the slides but I thought some folks might find them interesting. Let me know if you have any questions. 1. Comparison of Ancestry and Shared cm project relationship Ranges.
Comparison of Ancestr y and Shared cm project relationship Ranges Ancestry has published the expected range of shared cm used by Ancestry for estimating various relationships. The Shared cm Project is a collaborative data collection project managed by Blaine Bettinger. The Project has published ranges of shared cm based on DNA test results for more than 25,000 known relationships. The chart shows the averages and ranges of shared cm for various relationships from Ancestry and the Shared cm Project. Some substantial differences are shown for the shared cm ranges for Ancestry and Shared cm Project. The amounts of shared cm as a percent of the total chromosomal cm from the Shared cm Project and from basic genetics are also shown. Genetic Degrees of Separation Ancestry Predicted Relationship Ancestry's Range of Shared DNA (cm) Shared cm Project Observed Relationship Shared cm Project Ancestry Average (cm) Shared cm Project Ancestry 5th - 95th Percentile Range (cm) Shared cm Project Average Percent Shared Expected Percentage of Shared cm from Basic Genetics 1 Parent/Child 3475 Parent/Child 3445 3283-3671 50.0% 50.0% 2 Immediate 2400-2800 2585 37.5% 37.5% 2309-2841 Family Siblings 2 Grandparent 1729 1245-2184 25.1% 25.0% 3 Close Family 1450-2050 Aunt/Uncle/Ni 1720 25.0% 25.0% 1428-1998 ece/nephew 4 1C 680-1150 1C 849 636-1094 12.3% 12.5% 4 Great Great 876 12.7% 12.5% 406-1491 Aunt/Uncle Aunt/Uncle 5 1C1R 1C1R 420 215-635 6.1% 6.3% 6 2C 200-620 2C 219 93-390 3.2% 3.1% 6 1C2R 1C2R 217 67-384 3.1% 3.1% 7 2C1R 2C1R 112 31-221 1.6% 1.6% 8 3C 90-180 3C 64 14-146.93%.78% 8 2C2R 2C2R 64 18-141.93%.78% 9 3C1R 3C1R 39 9-100.57%.39% 10 3C2R 3C2R 30 7-69.44%.20% 10 4C 20-85 4C 29 7-68.42%.20% 11 4C1R 4C1R 22 6-50.32%.10% 12 5C - 8C 6-20 5C 18 6-39.26%.05% 13 5C1R 5C1R 16 6-39.23%.02% 31
The Leeds Method for Ancestr y Matches Preparation Enable the New & Improved DNA Matches feature Go to you Ancestry Matches Page Step 1: Select your 2 nd Cousin with the greatest amount of Shared DNA less than 400 cm (Carol Cassity) Step 2: Create a new custom group with a name and color for this Match (yellow, Carol Cassity) Step 3: Open the Shared Matches for that Match (Carol Cassity) and assign each of them to the same group. Step 4: Find the first person who does not have a color assigned (carol gallagher) and create new custom group with a name and color (orange, carol Gallagher). Open the Shared Matches for that person (carol Gallagher) and assign them to the same group. 32