Outline of Segment-ology

[00] Segmentology: Outline of Segmentology (14 Apr 2015 to 13 Aug 2023)

[01] Introduction and Disclaimer – I became an engineer in 1966; a Naval Officer in 1967; a genealogist in 1974; a registered Professional Engineer in 1980; a genetic genealogist (when I started a Y-DNA surname project) in 2002. I have bought original DNA kits at FTDNA (Y-111 and Big-Y, SNPs, FMS, atDNA), 23andMe, AncestryDNA, Genographic, Genos (exome), LivingDNA and MyHeritage; and uploaded to Y-Search, mitoSearch, NIH, GEDmatch, and DNA.Land. I present on genealogy and DNA to genealogy groups and conferences. I have no contract, compensation, or allegiance with any company. I am an unpaid volunteer at GEDmatch; a Surname Project Admin at FTDNA; and a long-time subscriber/researcher at Ancestry and FamilySearch. Statements/opinions are my own.

Segment-ology Table of Contents

[01A] Getting Started with Autosomal DNA Part I (22 Nov 2015)

[02] What is a segment? – Ancestral (true) Segments vs Shared (computer) Segments (7 May 2015)

[03] Measuring Segmentsbp (or Mbp); cM; SNP (13 May 2015)

[03A] Fuzzy Data, Fuzzy Segments – No Worry (30 May 2015)

[05] Segments

[05A] Segments: Bottom-Up (24 May 2015)

[05B] Segments: Top-Down (1 Jun 2015)

[05C] CA and MRCA (2 Jan 2016)

[05D] Crossovers by Generation (2 Feb 2016)

[05E] Anatomy of a TG (5 Feb 2016)

[05F] Sibling Crossovers (3 Dec 2022)

[05G] The Life of a DNA Segment (4 Jan 2022) *

[06] Segment size vs cousinship – Mathematical averages vs Range (Blaine’s data)

[06B] Segment Size vs Cousinship –Chart Needed –Estimated Curves (7 Nov 2015)

[06C] In Defense of Small Segments (21 Jan 2020) (Edit 2 Feb 2020)

[06D] Distribution of Cousins (9 Dec 2021) (Update/edit 19 Dec 2021)

[06Z] VUCA DNA (24 Aug 2015)

[07A] Ancestors – The Porcupine Chart (Biological vs Genetic Ancestors) (7 Aug 2015)

[07C] Proof of Stick Segments (16 Nov 2015)

[08] Triangulation Concepts

[08A] Your TGs are Pretty Unique! CONCEPT (7 Sep 2017)

[08B] The MRCA Knothole! CONCEPT (9 Sep 2017)

[08C] MRCA Knothole Guidelines. CONCEPT (10 Sep 2017)

[08D] Using a Group Common Ancestor. CONCEPT (20 Jun 2020)

[08E] Can Three Fourth Cousins Share the Same Segment? (12 Aug 2023)

[09] Benefits of Triangulation (9 May 2015)

[10] How To Triangulate: Collect, Arrange, Compare/Triangulate (11 May 2015)

[10A] Triangulating Your Genome (29 Dec 2020)

[10C] Triangulation: CA vs MRCA – diagrams [see [05C]

[10D] Using MyHeritage Labels for Triangulation (15 Dec 2021)

[10E] Triangulation on a Side Is a Snap (30 Jul 2023)

[11] Why Triangulation works (1 vs 2 chr; IBD segs)

[11A] Does Triangulation Always Work? (10 May 2015)

[11B] Does Triangulation Work? (19 Oct 2015)

[11D] Are Overlapping Segments Triangulated? (15 Apr 2020]

[13] Triangulation vs IBD

[13A] Small Segments and Triangulation (30 Sep 2015)

[14] Phasing DNA

          [14A] Phasing Your Ancestors’ DNA? (20 Apr 2022)

[14B] A Triangulated Group is an atDNA Haplogroup (2 Aug 2023)

[15] How Triangulated Groups (TGs) play out in practice.

[15A] Understanding and using TGs (18 Sep 2016)

[15B] The Attributes of a TG (19 Sep 2016)

[15G] A Targeted Process at AncestryDNA (20 Oct 2016)

[15H] Distribution of TGs – Part 1 ( 1 Oct 2021)

[15I] Distribution of TGs – Part 2 (5 Oct 2021)

[15J] Distribution of TGs – Part 3 (8 Oct 2021)

[15K] Distribution of TGs Part 4 (Spreadsheet) (13 Oct 2021)

[16] Segment analysis

          [16D] Endogamy PART I – Shared DNA (2 Dec 2015)

[16E] Endogamy PART II – One Segment from One Ancestor (5 Jan 2016)

[16F] Segment-ology: Endogamy – Get the Facts! (25 Apr 1922)

[18] Pile-ups: Small segments; TG segments (7 Oct 2015)

[19] Clustering

[19A] Think Icicles! (30 Oct 2018)

[19B] Icicles – Part 2 and Match Clustering (8 Jan 2019)

[19C] Shared Clustering – A Great Tool! (29 Nov 2019)

[19D] Walking the Clusters Back (1 Dec 2019)

[19E] Walking The Clusters Back II (5 Dec 2019)

[19F] Walking the Clusters Back III [14 Dec 2019)

[19G] A Unified Theory of Genetic Genealogy (16 Dec 2019)

[19H] Let the Matches Tell Us the Cluster Common Ancestor (20 Jun 2020)

[19I] Easy Manual Clustering at AncestryDNA (1 Jul 2020)

[19J] Use Clusters! (5 Jul 2020)

[19K] Breaking Down Brick Walls (3 Feb 2021)

[19L] Manual Clustering From the Bottom Up (15 Feb 2022)

[19M] Manual Clustering to Find Ancestors (26 Feb 2022)

[19N] Walking The Clusters Back  (22 Aug 2022)

[19Na] WTCB SITREP (21 Aug 2022)

[19Nb] WTCB Issue Alt MRCA (26 Sep 2022)

[19Nc] WTCB SITREP Nov 2022 (12 Nov 2022)

[See also these TIDBITS]

[22Z] Match Clusters – Chicken or Egg? TIDBIT (11 Feb 2019)

[22AA] Confessions of a Match Clusterer TIDBIT (14 Feb 2019)

[22AB] Walking the Clusters Back TIDBIT (14 Feb 2019)

[22AC] Match Cluster Report 1 (14 Feb 2019)

[22AD] D I Y Clustering TIDBIT (18 Feb 2019)

[22AE] Clusters Link to TGs and an Apology TIDBIT (22 Feb 2019)

[22AF] Clustering Programs TIDBIT (4 Apr 2019)

[22AP] Extending the MRCA of a TG through Clusters TIDBIT (18 Nov 2019)

[22AQ] Grouping Matches – Try It! TIDBIT (28 Nov 2019)

[22AT] Clusters at Brick Walls TIDBIT (7 May 2020)

[22AU] Using Ethnicity to Identify a Cluster TIDBIT (12 Jun 2020)

[21] Misc

[21A] Why Upload to GEDmatch or FTDNA? (11 Jun 2015)

[21B] Getting Started with GEDmatch (19 Sep 2017)

[[see also [22T] First Time at GEDmatch TIDBIT (1 May 2018)]]

[22] Segmentology TIDBITs

[22A] Crossover and Segment Formation TIDBIT (2 Jan 2017)

[22B] Number of Matches on a Segment (or TG) TIDBIT (2 Jan 2017)

[22C] Roughly Right is OK for Genealogy TIDBIT (2 Jan 2017)

[22D] Only One Comparison Needed to Add a Segment to a TG TIDBIT (2 Jan 2017)

[22E] Save the Clues TIDBIT (2 Jan 2017)

[22F] Walking the Ancestor Back TIDBIT (4 Jan 2017)

[22G] Uploading to GEDmatch TIDBIT (19 Jan 2017)

[22H] One Segment at a Time TIDBIT (18 Feb 2017)

[22I] Format for AncestryDNA Notes TIDBIT (7 May 2017)

[22K] Amount of DNA vs Number of Matches TIDBIT (17 May 2017)

[22L] Using a Child to Determine the Side TIDBIT (12 Jul 2017)

[22M] Triangulation at 23andMe TIDBIT (20 Jul 2017)

[22N] A Triangulation Overview TIDBIT (28 Jul 2017)

[22P] Using AncestryDNA Notes TIDBIT (9 Sep 2017)

[22Q] Make a Resolution to Contact Your Matches TIDBIT (7 Jan 2018)

[22R] When a Plan Comes Together TIDBIT [17 Mar 2018)

[22S] Contact Your Match Soon TIDBIT (15 Apr 2018)

[22T] First Time at GEDmatch TIDBIT (1 May 2018)

[22U] Confusion about Base Pairs TIDBIT [2 May 2018)

[22V] AncestryDNA Search on Notes TIDBIT (1 Jun 2018)

[22W] Shorthand ID for Common Ancestors TIDBIT (2 Feb 2019)

[22X] Shorthand ID for Triangulated Groups TIDBIT (2 Feb 2019)

[22Y] The Fundamental Building Blocks of Genetic Genealogy TIDBIT (3 Feb 2019)

[22Z] Match Clusters – Chicken or Egg? TIDBIT (11 Feb 2019)

[22AA] Confessions of a Match Clusterer TIDBIT (14 Feb 2019)

[22AB] Walking the Clusters Back TIDBIT (14 Feb 2019)

[22AC] Match Cluster Report 1 (14 Feb 2019)

[22AD] D I Y Clustering TIDBIT (18 Feb 2019)

[22AE] Clusters Link to TGs and an Apology TIDBIT (22 Feb 2019)

[22AF] Clustering Programs TIDBIT (4 Apr 2019)

[22AG] ThruLines Finds Your Common Ancestors TIDBIT (29 Jul 2019)

[22AH] Help ThruLines by Adding Children and Grandchildren TIDBIT (29 Jul 2019)

[22AI] ThruLines Has Xray Vision TIDBIT (29 Jul 2019)

[22AJ] ThruLines Helps with Y-DNA and mtDNA TIDBIT (29 Jul 2019)

[22AK] A Few ThruLines Are False, and Some Are Misleading (29 Jul 2019)

[22AL] Add ThruLines Info Into Match Notes TIDBIT (29 Jul 2019)

[22AM] Use Match Notes from ThruLines to Identify Clusters (29 Jul 2019)

[22AN] ThruLines and Clusters and Snowballs (29 Jul 2019) *

[22AO] How Does ThruLines Work TIDBIT (1 Aug 2019)

[22AP] Extending the MRCA of a TG through Clusters TIDBIT (18 Nov 2019)

[22AQ] Grouping Matches – Try It! TIDBIT (28 Nov 2019)

[22AR] AncestryDNA ThruLines Missing Out TIDBIT (26 Mar 2020)

[22AS] Download Your AncestryDNA Matches in 10 Minutes! (9 Apr 2020; Edit 8 Aug 2020)

[22AT] Clusters at Brick Walls TIDBIT (7 May 2020)

[22AU] Using Ethnicity to Identify a Cluster TIDBIT (12 Jun 2020)

[22AV] Find AncestryDNA Matches with Common Ancestors TIDBIT [8 Aug 2020)

[22AW] Percent DNA vs Percent Matches TIDBIT (4 May 2021)

[22AX] Search on a Surname TIDBIT (6 Jun 2021)

[22AY] Extending a Match’s Ancestry TIDBIT (13 Jun 2021)

[22AZ] Search on a Surname – Using It Part II TIDBIT (25 Jun 2021)

[22BA] Two Tricks TIDBIT (9 Jul 2021)

[22BB] Do You Have a Suspicious Branch in Your Tree? TIDBIT (28 Sep 2021)

[22BC] What Do You Get from a DNA Test TIDBIT [29 Sep 2021)

[22BD] Bad Segments – Good Segments TIDBIT (30 Sep 2021)

[22BE] Insights on Clustering vs Triangulation TIDBIT (13 Apr 2023)

[22BG] What Is Your Objective? TIDBIT (8 May 2022)

[22BH] Segment Data for Ancestry Matches TIDBIT (6 Jul 2022)

[22BI] It is Iterative TIDBIT (31 Jul 2022)

[22BJ] Segment Data for Ancestry Matches 2 TIDBIT (23 Feb 2023)

[22BK] Review the Comments TIDBIT (13 Dec 2022)

[22BL] Triangulated Group Analysis TIDBIT (10 Jan 2023)

[22BM] Small Segments Needed for Distant Ancestors TIDBIT (6 Mar 2023)

[22BN] Distant Common Ancestor Couples TIDBIT (7 Mar 2023)

[22BO] The Two Meanings of TG TIDBIT (7 Apr 2023)

[22BP] Who Ya Gonna Call? (hint: NOT Ghostbusters!) TIDBIT (28 Apr 2023)

[22BQ] How To Detect False Matches Theory (6 May 2023)

[22BR] How to Define the Most Recent Common Ancestor TIDBIT (13 May 2023)

[22BS] Does the DNA Come from the MRCA Father or Mother? TIDBIT (15 May 2023)

[22BT] Using the Shared cM Project in Reverse TIDBIT (1 Jun 2023)

[22BU] A Means To An End TIDBIT (11 Jun 2023)

[22BV] Identifying False Shared DNA Segments TIDBIT (18 Jun 2023)

[22BW] Getting ThruLines to Work for Me TIDBIT (7 Jul 2023)

[22BX] Triangulated Group Segments Are Like mtDNA TIDBIT (28 Jul 2023)

[23] Ancestors

[23-37P] Breaking Thorough a Brick Wall (5 Aug 2019

[23-38P] Ahnentafel 38P – John ALLEN Family (26 Jan 2022)

[23-98Ma] Testing a Guess With Teamwork! (10 Mar 2023)

[23_98Mb] Percent of Shared Cousins Indicates Relationship (15 Mar 2023)

[30] Bio-Ancestors

[30A] Bio-Ancestors – Testing a Line (20 Apr 2021)

[30B] Finding Bio-Ancestors (2 Jun 2022)

[30C] How Many NPEs Do You Have? (25 Mar 2020)

[35] Tools

[35A] ThruLines at AncestryDNA

(see also these TIDBITS]

[22AG] ThruLines Finds Your Common Ancestors TIDBIT (29 Jul 2019)

[22AH] Help ThruLines by Adding Children and Grandchildren TIDBIT (29 Jul 2019)

[22AI] ThruLines Has Xray Vision TIDBIT (29 Jul 2019)

[22AJ] ThruLines Helps with Y-DNA and mtDNA TIDBIT (29 Jul 2019)

[22AK] A Few ThruLines Are False, and Some Are Misleading (29 Jul 2019)

[22AL] Add ThruLines Info Into Match Notes TIDBIT (29 Jul 2019)

[22AM] Use Match Notes from ThruLines to Identify Clusters (29 Jul 2019)

[22AN ] ThruLines and Clusters and Snowballs (29 Jul 2019) *

[22AO] How Does ThruLines Work TIDBIT (1 Aug 2019)

[22AP] Extending the MRCA of a TG through Clusters TIDBIT (18 Nov 2019)

[22AR] AncestryDNA ThruLines Missing Out TIDBIT (26 Mar 2020)

[35B] Genetic Genealogy Spreadsheets (7 Dec 2021)

[35BA] Ancestor Spreadsheet (22 Dec 2021) (Edit 23 Dec 2021)

[35BC] Common Ancestor Spreadsheet (19 Dec 2021) * [see also 15K]

[35BD] TG Master Spreadsheet [not yet posted]

[35BE] TG Summary Spreadsheet (22 Dec 2021)

[99A] Anatomy of an IBS segment by Ann Turner  (2 Oct 2015)

[99B] Advanced Genetic Genealogy Book (6 Apr 2019)

9 thoughts on “Outline of Segment-ology

  1. This is great! I just finished NGS’s online Genetic Genealogy course and needed more detail. They included your website in their list of Recommended Reading — my thanks to the course designer for directing me to you, and my thanks to you for a great series of blog posts!

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  2. Jim, a thousand thanks for your work on this, which I was introduced to through a superb course by Maurice Gleeson. Thanks also for being the inspiration for GedMatch.com’s Tier 1 Utility “Triangulation Groups – Beta.” After getting hooked on its great functionality, I note that it has been down for the last 5 days or so. Are you (or they) working on it?

    Like

    • Maureen, Thanks for your kind words. The Tiangulation programs at GEDmatch are a great way to start your TGs and mapping. But after that start, I just add new Match-segments to my spreadsheet and check them against overlapping segments which are already there. I am not working on the software, maybe the tech guys are. Jim

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  3. Jim, I know you have ‘spreadsheets’ on your to-do list, but do you have yours or a dummy version of it (stripped of your own data) available anywhere for a peek at? I am in the early stages of the process and I can see it will take me a couple years to re-invent my own wheel. I’m particularly interested in how you organized your family tree info to facilitate searching for MRCA with matches, and organizing data for triangulating.

    Liked by 2 people

  4. I am so thankful for all of your explanations on all of your blogs I am learning so much. I am so grateful to you for sharing your expertise with all of us because it becomes so frustrating many many thanks for all of your hard work and sharing of your expertise

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