Harold&Robert Casey

Harold Casey and son, Robert Casey, ca. 1980. Harold and Robert holding the camera ready copy for their book, "Casey Family History," published in 1980 (out of print for over 10 years now - electronic version still available at this web site). Seems like only a few years ago. Harold was the founder and president for over 10 years of the Stillwater Genealogical Society in Stillwater, Oklahoma.
 



Source Documentation for DNA research

This section is included to assist others in getting up to speed on how DNA testing can be used by genealogists to connect earlier Casey ancestors. Here are several kinds of sources:

- Good paper back books to read to get started (highly recommended)
- Links to DNA presentations for genealogists
- Links to other web sites that have primers on DNA
- Source files for Y-DNA marker mutations rates and distributions of marker values
- Good scientific research papers on DNA for genealogists

Good paperback books to read

I highly recommend two books to start getting up to speed for DNA testing for genealogists. There are twenty or thirty other books available on Amazon.com on this topic as well (reviews are pretty accurate). Most books have some unique material or unique approaches that are worth while. Unfortunately, none of these books address some of the more complex topics that many better DNA Projects address daily.

"Trace Your Roots with DNA, Using Genetic Tests to Explore Your Family Tree," by Megan Smolenyak and Ann Turner, 2004 is the first book that you should purchase. This book is well organized and well presented. It gives a broad overview of many DNA tests available to genealogists (too broad coverage on less useful tests and too little coverage of Y-DNA testing). However, this is by far the best book to get up to speed for DNA testing for genealogists. This book does not address advanced Y-DNA topics in depth and leaves you with the impression that there are a broad range of useful tests (this is really not true). It gives mtDNA testing too much coverage (not very useful for genealogists).

"Family History in the Genes, Trace your DNA and grow your family tree," by Chris Pomeroy, 2007. This book is by far the best book to address on how DNA can be used by genealogists to grow their family trees. Chris has run a successful DNA Project for years and was one of the pioneers of DNA testing for genealogists. His book is full of examples of how DNA testing has actually revealed new genealogical information in real scenarios. If you are running a DNA Surname Study or assisting in running a DNA Surname Study, then this book is a must read book. This is his second book, if you like this book, his original book has additional information (although a lot of common information). Chris correctly goes into depth about how critical traditional research is to any DNA analysis.

DNA Presentations (at this web site)

These presentations are good summaries of how DNA is used for genealogists, but lack the verbiage that goes with these presentations. However, these presentations bridge the gap between published paper books (too little depth) and research papers (too much depth). Below is a link to genealogical presentations that I have presented in the last few years (includes two presentations on DNA for genealogists):

Genealogical Presentations by Robert Casey

Below is a presentation available from Family Tree DNA. This presentation is great for getting you started. It goes into too much detail about mtDNA but does address many of the basics of DNA for genealogists:

Family Tree DNA_101_Tutorial

Here is another presentation that is very broad – but does a good job of separating deep ancestral testing from testing for genealogists. This presentation is an entertaining presentation that shows numerous specialized tests of DNA:

Entertaining presentation on DNA

Links for getting started with DNA for Genealogists

WorldFamilies.Net has an excellent web site on many of the basics for Y-DNA testing. It has many links and topics covered that represent a good coverage of common issues that genealogists face with DNA testing:

http://www.worldfamilies.net/

The University of Utah has an excellent video that describes how the four basic types of DNA work. Unfortunately, it does not inform the public that are very few X-DNA markers that are passed from mother to daughter that mutate at a rate required for genealogists (this is currently an expanded paternity test). It also does not explain that mtDNA mutates much too slowly for genealogists and is primarily useful for deep ancestry. Autosomal DNA (Family Finder tests) may be useful for genealogists but is just now becoming available from FTDNA and competes for funds for Y-DNA testing:

http://learn.genetics.utah.edu/content/extras/molgen/

Source files for Marker value mutations & mutation rates

The rarity of marker values is becoming a much more important source to the DNA analysis. This topic is rarely discussed in depth in most publications or presentations but many DNA projects are now using this information in their analysis. To my knowledge, their is only one definitive article that shows the distribution of marker values for several major haplogroups. After reviewing these tables, it is now obvious how Family Tree DNA estimates haplogroups based on Y-STR markers. There appears to be a relationship between Y-STR markers and Y-SNP markers. Since these files are usually found in forums and tend disappear over time. I have downloaded and created a Acrobat file to ensure preservation of this very important source document:

Frequencies of DNA Marker Values

Mutation rates also important in determining how trustworthy mutations can be for genealogists. If mutation rates are too high, it should be expected that multiple independent mutations can result in any cluster and backwards mutations are more likely within a cluster. There are many studies on this topic and new 2011 study combines 110 Y-STR markers from 26 different studies. Here are the three files for this study:

table that summarizes mutation rates

scientific article that collection of 26 studies

tables that summarizes of the 26 studies

Another recent study not only shows mutations from their study but also compares their mutation rates with the mutation rates made available by Family Tree DNA. Unfortunately, this web site is no longer available but I saved only the mutation rate table summary spreadsheet:

Mutation Rates by Burgarella - 2010

Here is the ground breaking study that was done by Chandler several years ago. Chandler was one of the first to study mutation rates for markers used by genealogists:

Mutation Rates by Chandler - 2006

Not only are DNA characteristics important to genealogists, but commonality of the surname is another important factor in DNA analysis. For very common surnames, you should expect many independent genetic origins. When attempting to connect many clusters together with a common deep ancestry, the frequency of the surname is an important factor. This study was issued by the United States Census Bureau based on 1990 census records:

Frequency of Surnames

Great scientific articles that address important issues

The internet is great for finding leading edge information discussing DNA issues that affect genealogists. Most of the scientific articles are very heavy reading but are so important that they warrant reading multiple times. Other articles clearly document how DNA works and clears up misconceptions that genealogists regularly have. An article by Mark Jobling had a profound effect on my analysis methodology. I am not sure that Mark even intended to directly make the point that I gleaned from his presentation. Mark introduced the topic of overlapping haplotypes which really made a light bulb turn on for me. Most people assume that common DNA always implies close genealogical relationships. Even the FTDNA MRCA calculators imply this conclusion. However, these conclusions usually assume a common surname for the submissions and may not apply to very common surnames as well. if your line has too common DNA values, it can overlap with a lot of non-related submissions. Caution this is heavy reading:

Overlapping Haplotypes by Jobling - 2000

I just really enjoy articles by Chris Pomeroy as he has such good insight of how DNA can be used by genealogists. This article goes into a lot depth of the importance of traditional documentation being required for DNA analysis which many DNA Projects do not emphasize in their analysis. Analyzing DNA submissions is difficult enough - but bad traditional documentation can pollute the analysis of DNA as well. One can not be separated from another as both are primary sources. This article is not a difficult read:

Dual Approach by Pomerory - 2009

Occasionally, you need to locate scientific articles that support some of your assumptions that are not covered in most publications or presentations. There are two methodologies on determining DNA of our most recent common ancestors. One approach is "majority rules" and another approach assumes "lowest value" must be the MRCA. The "lowest value" approach is just not correct. The "majority rules" also has issues but is much more accurate. The following article clearly documents that mutations are in both directions (adds and deletes). This article is only shown as a reference to document the add/delete issue:

Adds & Deletes - 2000