Uniquely Numbering Each Ancestral Line, Generation, Pairing and Sibling


Your New Ancestral Lines Pairing System

A new pedigree numbering system has been developed for the family history and genealogy community as an alternative that visibly displays ancestral lines and generations in multiple presentation formats. This follows straightforward genealogical thinking and addresses important needs in selecting your numbering system. For a pedigree chart, the result may look like that in the following example:

A classic "bow tie" chart is even more revealing of the symmetry in the new system, as in the following:

The initial publication concerning this system is an article published online by the New England Historic Genealogical Society (NEHGS) in Boston, which can be accessed free of charge in the publications archive at www.americanancestors.org. Please take a few minutes to read this – especially the full PDF version – and then perhaps contribute your own ideas and comments through this Ancestral Lines Website concerning the system and it's apparent benefits.

The Ancestral Lines format is easy to read and understand, with unique indicators recording relationships briefly with key information – setting each direct Line as a continuous ancestral lineage, then visibly numbering successive Generations along each Line. A few brief video introductions are available on this Web site, on the Online Videos page.

With Ancestral Lines, all ancestors are individually numbered without first compiling a comprehensive set or naming every individual. Line numbers are added in the new system at one half the rate individuals are added in the Ahnentafel method, and these smaller numbers continue to be used into the deeper ancestries. These therefore are not merely “index” locator numbers; they also visibly convey additional information beginning with the individual’s family line and generation.

The basis of the Ancestral Lines Pairing System is to show the appropriate Line and Generation as the unique indicator for each direct ancestor. This begins by numbering the Lines in proper sequence for this outcome, calculating branching maternal Lines based on the descendant’s paternal Line number and parents’ Generation number.

The initial Lines and Generations calculated for direct ancestors, displayed in a straightforward two-number format, as shown above, can be used effectively in many applications. The next alternative to consider is to build on this basic framework in a three-number format and uniquely number all Siblings and paternal or maternal half-Siblings of the direct ancestry consecutively.

Ancestral Lines readily supports both the Y-DNA and mtDNA studies often paired with traditional family research. Patrilineal Line 1 can conveniently represent the Y-DNA line, and Ancestral Lines’ straightforward Generational numbering then matches with the testing companies’ and others’ supporting software formats that indicate the probabilities of when a Most Recent Common Ancestor (MRCA) is shared. Alternatively, the Matrilineal line of mother-of-mother ancestry, corresponding with mitochondrial DNA (mtDNA) test results, can just as conveniently be set as Line 1. These and other aspects of genetic genealogy applications are discussed under "DNA Studies" on this Website.

To fully account for Sibling relationships, there is then the option to number all the Pairings of each direct ancestor and thereafter number all offspring as Siblings within their Pairing. With this alternative, a four-number format assigns a number for each Pairing by Line and Generation in the entire collateral family, and then assigns a number for each Sibling within their nuclear family. This extended approach most clearly identifies different Pairings as well as the half-Siblings of collateral Pairings, of which there may be several in any Generation, both paternal and maternal. All three approaches are covered in the full PDF version of the recently published article.

Ancestral Lines is mathematically based and readily computerized. It is also, by its very nature, not constrained by time or place – hence the introductory titles in English and 12 other widely-used languages above. The idea is that we all can use Ancestral Lines to help celebrate our heritage! And we are on our way, with the following countries each represented by multiple visitors to this Website during its first few weeks: USA, Netherlands, Belgium, Canada, United Kingdom, Australia, Germany, Israel, New Zealand, Spain, Mexico, Slovak Republic, France, Ireland, Colombia, Brazil and Russia.


The Ancestral Lines Pairing System (Ancestral Lines) is a specific application of U. S. Patent 8,447,763, “Numbering System for Antecedents and Outcomes,” which also is covered by international Patent Cooperation Treaty Regulations (Washington, DC: USPTO). Ancestral Lines is freely available for personal record-keeping, research, education and other non-commercial uses, and readily may be licensed without charge for commercial purposes. Please see Ancestral Lines Developments on this site for additional information.

"An Ancestral Lines Pairing System: Uniquely Numbering Each Ancestral Line, Generation, Pairing and Sibling" article © Copyright 2011 Capers W. McDonald.

This Web site and all images it contains are being used for limited and noncommercial purposes, principally colleague and collaborator communications and shared learning.


The fourth annual RootsTech convention was held in Salt Lake City, Utah in early February 2014, at which time participants heard from technology leaders and innovators in the family history industry, learned new skills and best practices, and discovered technology tools through interactive presentations and hands-on workshops.

Ancestral and Descendant Lines was presented and discussed on February 5 as Innovator Summit session DEV 1330.

Ancestral Lines was first presented in an interactive forum by Capers McDonald at RootsTech 2012.

Online Videos

Topics closely related to Ancestral Lines are presented on this site in a video forum by various contributors.


The first Ancestral Lines article was published online in 2011 by the New England Historic Genealogical Society at www.AmericanAncestors.org. The full PDF version is recommended.


Founded in 1845, the New England Historic Genealogical Society is one of America's leading resources for family history research. Their staff and members help build knowledge, skills and understanding of each family and its place in history. They provide more than 25,000 members worldwide access to some of our most valuable and unique genealogical resources.

2011-12 SURVEY

A representative group of genealogists and family historians participated in Ancestral Lines’ survey concerning work with ancestral lineages and pedigree numbering systems. Findings are summarized here.

Survey Results

The 2011-12 survey consisted of nine multiple-choice questions, and responses to all are summarized on the Survey Results page.


FamilyChartmasters in Utah now have the capabilities to produce a variety of Ancestral Lines numbered charts. As shown on this site, these include their Generation Maps as well as traditional Ancestor Charts and Ancestor Charts with Siblings.


Participating in our family history and genealogy community:

Tech Talk

What would it take to code this? You could contribute!

Survey Results

Findings here...Is some of this surprising?

Others Speaking

What people are saying. You should contribute as well!

Features & Benefits

Both users and developers think in these terms...

DNA Studies

What's up with genetic genealogy?


Plans and Prognostications: What is likely to happen next?