O'Shea Clan
DNA Project

How to Particpate

O'Shea DNA Project

Technical Information

I am not a geneticist, so my ability to provide technical information is essentially limited to pointing you in the direction of articles and online resources that will hopefully prove useful. For most of these, however, you will need to have a pretty good grasp of genetics. If you do not, I highly recommend that you read the following online introductory articles:

The Y Chromosome In The Study of Human Evolution, Migration and Prehistory
Neil Bradman and Mark Thomas

GENETICS AND GENEALOGY: Y Polymorphism and mtDNA Analyses
Kevin F. Duerinck, Esq.

An Introduction to Genetic Genealogy
Alan Savin

What is Molecular Genealogy?
Brigham Young University

Technical Information on Y-Chromosome Testing
Chris Pomery

The article above by Chris Pomery contains a wealth of information, including links to more technical information and sites, as well as a list of single surname DNA projects underway.

Most Recent Common Ancestor (MRCA)

The estimation of the most recent common ancestor is a matter of probabilities, not of certainties. The more markers employed, the more precise the estimate may be. The following chart shows the curve for 50% time within the range of possible generations of ancestry for the MRCA. This curve thus gives the estimate of greatest probability for the number of generations for the MRCA, but a rather wide range is possible, especially when there are fewer markers. The probabilities show are for a 100% match (i.e., all markers of the number indicated).

And now for the really technical stuff...

The following articles (all in Adobe PDF format, requiring free Acrobat Reader) provide excellent context for understanding y-chromosome testing and its potential. However, be warned that they are written predominantly for professionals in the field of genetics.

Y-chromosome variation and Irish origins

In the name of the father: surnames and genetics

An Extensive Analysis of Y-Chromosomal Microsatellite Haplotypes in Globally Dispersed Human Populations

Estimating the Time to the Most Recent Common Ancestor for the Y chromosome or Mitochondrial DNA for a Pair of Individuals

Mutations at Y-STR loci: implications for paternaity testing and forensic analysis

Genetic evidence for different male and female roles during cultural transitions in the British Isles

The Genetic Legacy of Paleolithic Homo sapiens sapiens in Extant Europeans: A Y Chromosome Perspective

Y chromosome sequence variation and the history of human populations

High-Resolution Analysis of Human Y-Chromosome Variation Shows a Sharp Discontinuity and Limited Gene Flow between Northwestern Africa and the Iberian Peninsula

High resolution Y chromosome typing: 19 STRs amplified in three multiplex reactions (Iberian Samples)

Detection of Numerous Y Chromosome Biallelic Polymorphisms by Denaturing High-Performance Liquid Chromatography

The phylogeography of Y chromosome binary haplotypes and the origins of modern human populations

Y-Chromosomal Diversity in Europe Is Clinal and Influenced Primarily by Geography, Rather than by Language