News release dated February 2022:
Project and paper update:  

     Paper: 'Using Data Analytics to Interpret Haplogroup Evolution applying surname, surname origins and TMRCAs' - in progress

     Development workbook: 'Sullivan yDNA (sullivansofsaratogasprings.com)' - published also see 01122021 Eoganacht analytics copy.xlsx (live.com)

     Reference papers:

     Archive:

What is a time to the most common ancestor (TMRCA)? Example using the CTS4466 Haplogroup and CTS4466/A541/S1121 SNP

Each parent contributes 23 pairs to their offspring; i.e., 50%each.  The 23 pair determines the sex of the child with the mother contributing and XX and the father an XY chromosome.  The Y of the male is referred to as yDNA consisting of slower mutating single nucleotide polymorphisms (SNPs) [1] and faster mutating multi-allele markers called short tandem repeats (STRs) [2].  It is not recombinatory meaning that each male inherits his father's SNPs and STRs of their male lineage; a SNP mutation occurs in a single man and is inherited by his descendants and not found in his father or make siblings.  It is one of the best ways to trace the male ancestry especially since the STR mutations are predictable and are unchanged being an excellent means of dating the occurrence of SNPs.  The way the STRs calculate the SNP date range is called finding the time to the most recent common ancestor or TMRCA.  

Each group of STRs used in the TMRCA calculation is a single sample since the full population cannot reasonably be tested at any time therefore the science to determine a TMRCA is based on inferential statistics resulting in a confidence interval.  The complete study of yDNA TMRCAs includes the full collection of TMRCA dates with confidence intervals.

There are many different types of TMRCA calculators and each is based on a statistical formula which may stem from different scientific backgrounds.  The core of each calculation is a mathematical formula that references how to estimate the date range based on the mutation rate of the changes in STRs.  The TMRCA calculation I use is founded on the work of Dr. Anatole Klyosov, a former visiting professor of Biochemistry at Harvard University, which is based on biokinetics [3]. 

Since yDNA traces the male lineage unchanged yDNA can be mapped into an evolutionary tree indicated by Haplogroups labeled from A - T; see figure1.1 Haplogroup Tree. 

Figure 1.1 Haplogroup Tree [5].  R1-CTS4466 is shown.


Method of linking yDNA to history:
For patrilineal societies that follow male ancestry, the time of the adoption of surnames around 1000-1200 AD (depending on the country) more closely linked the adopted family surname to the male lineage yDNA.  "Surnames were chosen, assigned or changed over time[4]. The main sources of surnames are:

1. Toponymic (a geographical location of their farm, county, town or estate such as Lancaster, Hampshire or Berkley),
2. Topographical (a physical characteristic of the land such as Hill or Knolls such as Mary of Wood),
3. Relational surnames from the dynasty eponyms that may assume obligation of mutual protection or eligibility of participating in events with certain privileges,
4. Personal names from characteristics (Swift, Red and Blunt meaning fair haired),
5. Occupational that may include formal or informal licensing (Smith, Hunter or Weaver as examples) names [6][7].

Relational surnames based on dynasty eponyms are unique in that they linked their surnames to their yDNA lineage even before the time that surnames were adopted in the general population therefore have stronger and more closely linked yDNA evidence."

With excellent genealogical records, an effective TMRCA calculator, enough yDNA descendant SNP and STR results along with DNA Genealogy analytical methods, it is possible to link yDNA to historical records which is known as inferring past history of descendants.

Steps to creating a TMRCA using the KK calculator:

KK Calculator download latest version from Anatole Klyosov andsearch for 'DNA Genealogy TMRCA Calculator'; see Klyosov, Anatole (2018) DNA Genealogy, Scientific Research Publishing, Inc. USA [8].

How to use the KK Calculator:

The yDNA STRs of an individual male are called a haplotype.
 
Assumptions:

Use only results from a single Haplogroup.

The haplotypes (STRs) need to be in a series; example haplotypes associated with a SNP.

Technical details:

           FTDNA STR panels with corrected data that separates multi-alleles.

           At least 4 STR haplotypes are needed to build a reliable calculation.

           Haplotype (STR) panels need to be the same length

Example 1: Quick Start – using cleansed data - video module 1.1 download video

Open software and data source-

1.    KKCalculator – go to AnatoleKlyosov's Web Page (anatole-klyosov.com)

Download calculator:

-     search for DNA Genealogy TMRCA Calculator

-     download Kilin-Klyosov TMRCACalculator. Slow download, 40 Mb.

2.   Download corrected data source (multi-alleles are updated to single alleles) - cleaned data

S1121: current date - ybd (1509) = TMRCA         2021 - 1509 = 512 AD  

                  TMRCA - MOE(154) = lower  bound          512 - 154 = 358 AD         

                   TMRCA + MOE(154) = upper  bound         512 + 154 = 666 AD

                These numbers are interpreted as SNP S1121 having a TMRCA of 512 AD +/- 154 years or a confidence interval from 358 - 666 AD.

References:

[1] International Society of Genetic Genealogists. Single-nucleotide polymorphism. 2019.url: https://isogg.org/wiki/Single-nucleotide_polymorphism/en.

[2] International Society of Genetic Genealogists. Short Tandem Repeat. 2019. url:https://isogg.org/wiki/Short_tandem_repeat.

[3] Anatole A Klyosov. “DNA Genealogy, mutation rates, and some historical evidences written in Y-chromosome. I. Basic principles and the method”. In: Journal of Genetic Genealogy 5 (2009), pp. 186–216

[4] Kathleen Kerwin 2021. Chapter 'Sullivan yDNA Supports existence of Eoganacht Dynasty', Oak and the Serpent MD Facog Facs Gary B.O’Sullivan, Gold Stag Communications, Inc. (revision in progress), page 3.

[5] Anatole A Klyosov et al. “Reconsideration of the “Out of Africa” Concept as Not Having Enough Proof”. In: Advances in Anthropology4.01 (2014), p. 18.

[6] Turi E King and Mark A Jobling. “Founders, drift, and infidelity: the relationship between Y chromosome diversity and patrilineal surnames”. In: Molecular Biology and Evolution 26.5 (2009), pp.1093–1102.

[7] Turi E King and Mark A Jobling. “What’s in a name? Y chromosomes, surnames and the genetic genealogy revolution”. In: Trends in genetics 25.8 (2009), pp. 351–360.

[8] Anatole A Klyosov. DNA Genealogy. Scientific Research Publishing, Inc. USA, 2018.