Sunday, May 26, 2013

Non Genetic Relatives In A DNA Database

Finding a relative that doesn’t match my DNA in a DNA database? That’s preposterous, isn’t it? One of the reasons many of us have chosen to test with 23andMe and other companies is to find unknown relatives that match our DNA. True, but we also have relatives with whom we have no matching DNA, and some of these should appear in 23andMe's database. If you have tested other relatives, you have an opportunity of finding some of these non-matching individuals. Indulge me while I explain.

While I was allowing my mind to wander concerning autosomal testing the other day, I came to the realization that I have relatives with whom I have no significant genetic connection, and that these individuals may be found in 23andMe’s database. I’ve really known this for a while, as I have tested a number of close family members and they have matches that I don’t have. No doubt I am related to some of these individuals. Because of recombination, the amount of DNA we receive from a given ancestor is diminished in each generation. Therefore, not everyone who is legitimately related to us shares DNA with us.

This is best understood with close relatives. Since I’ve tested my mother and two brothers, approximately half of their matches do not share any segments of DNA at 5cM or higher with me and therefore do not show in my “DNA Relatives” (formerly “Relative Finder”) on 23andMe. In other words, for every 50 matches I share with my mother, theoretically she has 50 matches that I do not share. The same goes for each brother.

In addition, I’ve known since I began testing fourth cousins, that some would match me and some would not. I am related to these individuals, but we simply do not share any DNA. For example, I have 6 fourth cousins and 1 fourth cousin, once removed who have tested. I share no significant amounts of DNA with the fourth cousin, once removed and none with 4 of the 6 fourth cousins. Just because I do not match some of these cousins, it doesn’t mean we are not related. There is only a 45% chance that you will match a known fourth cousin.

I then realized that, although I was not matching these relatives, there were others they matched who were possibly related to me. So the first step in this process was to determine the percentage of possible relatives a particular individual might share with me and then calculate the mean number of that person’s matches with which I might share DNA.

While the percentage of total ancestors I would share with a person would be absolute, the percentage of a person’s matches I would share with an individual would be an approximate. Since there is randomness in recombination, I might share more or less than an average amount with a person.

For example, a sibling will share an average of 50% of his or her DNA with other siblings. I share 49.6% of my genome with my oldest brother, which is fairly close to the average of 50%; however, my other brother and I share only 41% of our DNA – which is considerably less than average. Therefore, I could expect that I have lesser number of DNA matches with this brother than I do with our oldest brother.

The second factor is due to nature of 23andMe’s database. There will be a lesser number of potential matches from ancestral populations that are not well represented. For example, I have about 30% German ancestry from my mother’s family; however, I have a smaller number of German matches than I do through my father’s New England Colonial family. Therefore, predicting the number of actual non-matching relatives we have in the database is entirely dependent upon 23andMe’s customer base.

Therefore, no amount of calculation will be correct in regards to the two issues of the random nature of recombination and database limitations.

The following chart explains the percentage of a relative’s ancestors we have in common and the average amount of DNA we should expect to share.

Relationship Shared Ancestry Average Shared DNA
Identical Twin100.00%100.00%
Double Cousin100.00%25.00%
Great Grandparent100.00%12.50%
Great Aunt/Uncle100.00%12.50%
Half Sibling50.00%25.00%
Half Aunt/Uncle50.00%12.50%
1st Cousin50.00%12.50%
Half Cousin25.00%6.25%
1st Cousin, Once Removed25.00%6.25%
2nd Cousin25.00%3.13%
Half Cousin, Once Removed12.50%3.13%
2nd Cousin, Once Removed12.50%1.56%
3rd Cousin12.50%0.78%
4th Cousin6.25%0.20%

In the above table, the numbers in the second column represent the absolute percentage of that person’s ancestors we would actually share. For example, a first cousin, once removed seems high at 25%; however, if we consider that we share 100% of the ancestors of our parents’ siblings, and we do, then an aunt/uncle’s child (a first cousin) is half that amount at 50%. Therefore, our first cousin’s child shares 25% of his or her ancestors with us. We would be related to 25% of our first cousin, once removed’s ancestors and approximately 25% of that person’s potential relatives.

The exact number of relatives that we share will vary due to the number of actual relatives that person has. For example if we have 20 first cousins on our father’s side and only two on our mother’s side, we will have more paternal relatives than maternal, so the numbers only work in theory. 

The third column represents the average amount of DNA we share with our relatives at each level. Using our first cousin, once removed again as an example, we only share 6.25% of our DNA with this relative – therefore, we should match about 6.25% of that cousin’s 23andMe matches. Again if all things were equal (and they are not), we might expect to be related to 18.75% of that person’s matches, but not share any DNA with these individuals. Again, these percentages are not absolutes, but approximations.

With those with whom we share 100% of their ancestors, determining who is related to us in their DNA Relative list is easy – it is everyone; however, it is possible to determine who may be related to us in the lists of relatives that share a fraction of their ancestors with us.

To do this, we must compare two relatives that are mutually related to us and each other and find out who they match and determine who matches us and who does not. The relationship of the two individuals must not be any closer than our relationship with either one. For example, I have two fourth cousins who have tested and who are siblings. Their relationship as siblings will produce matches from ancestries for which I have no relationship. Likewise, two other fourth cousins who are second cousins to each other cannot be compared either without producing matches to individuals with whom I could not possibly be related.


The procedure for doing this is to download DNA Relative files and compare these in Excel. Find two relatives that have at least an equal or greater distance from each other as your closest relative of the two does to you. Create a column in one of the files that you mark each row in the same manner; I used an “x” and give it a name like “ID.” Add a column to the second file and leave the column blank. Copy the second file and paste the rows below the first.

Once done, highlight the header row (Row 1). Click the “Data” tab and select “Filter” (or use Ctrl+Shift+L).  Highlight the "Name" column, select the drop down arrow and select “Sort A to Z.”  The names across both data sets will be in alphabetical order.

Next, highlight the “Name” column. Click the “Home” tab. Click “Conditional Formatting” and then “Highlight Cells Rules.” Select “Duplicate Values.” Some of your cells in this column should become highlighted in the default color – generally pink.

Open a new Excel file, copy the header row into it, and keep the file ready. Go back to the original file’s “Name” column and click the down arrow on the header. Select “Sort by Color” and select the color of the duplicates. This arranges all of the duplicates in alphabetical order. Copy all of the duplicates (highlighted in pink) and paste these into the new file. Now delete all of the rows that have something in the name field.

Repeat the process, with the “Family Surnames” column and then the “Family Locations” column. You can work through the rest of the copied databases, but unless you are very familiar with Excel, I would suggest not doing this as you will have the possibility of introducing non-matches in your final spreadsheet by accident. In the new spreadsheet, go to the “ID” column, select the down arrow and “Sort A to Z.” Delete all of the rows with no “x” in this column and that eliminates all of the duplicates in the spreadsheet.

What remains are a portion of those who the two relatives share and who may be related to you. You can paste your data onto this spreadsheet, and repeat the duplicate values, as you did with “Name,” for “Family Surnames” and “Family Locations.” If there are any duplicates, these are the individuals that you and your two cousins share. If it is a short list, the quickest method is to open your DNA Relatives page on 23andMe and use the search feature there.  Good luck. 


There is no guarantee, however, that these individuals are actually related to you or related to you in the same lineage as to those with whom you are comparing. A case in point, my half cousin (through my father’s mother) is related to my fourth cousin (through my father’s father) with 14cM shared; however, they are related in an unknown manner and from different lines than I am related to either one of them.

My sister-in-law also shares 9cM of DNA with this same fourth cousin, albeit, it is via a completely different lineage. Both of these relatives share more with my documented 4th cousin that I do (5cM). Therefore, just because your two relatives have a common DNA cousin, this individual may not be related to you or if they are related to you, they may be related along another lineage.

There will be qualifying individuals that you will not be able to determine if they match both subjects.  I have determined these matches based on three criteria: name, family surnames, and family locations - these are the only three columns that will consequently prove the individual on both lists is the same.  Just because two individuals have the same haplogroups does not mean they are one and the same.  Therefore, we will miss some of our matching relatives by virtue of a lack of information.

Finally, we may match the same individuals; however, we may match on a different segments or even different chromosomes than than the other two individuals.  The closer the relationships, the more likely we will have matches on identical segments or portions of identical segments.


I decided to put this into practice and here’s what I was able to discover with several of my family members who have tested.

First Cousins

I looked at the matches between my two maternal first cousins who are also first cousins with each other. They had 93 matching individuals with only six matching me. Because of my very close relationship to both of these women, I would venture to say that most if not all of these matches are my non DNA relatives. In comparing the 93 individuals with my mother, she matches all but 20 – these twenty relatives would never have been known to me had I not conducted this exercise.

Multiple Relationships/First Cousins Twice Removed

This is a fairly unique comparison as I am related to both individuals in two different ways; however, the lineages are the same for both. With subject “A,” I am her second cousin via her grandmother and her second cousin, once removed through her grandfather. To visualize this, our grandmothers were sisters. Her grandfather was my grandfather’s uncle. I share 50% of her ancestors and she shares 37.5% of mine in this unique relationship; together we share 5.34% of our DNA.

To Subject B, I am his second cousin, twice removed via his 2nd great grandmother and a third cousin, once removed through his 2nd great grandfather. I share 12.5% of his ancestors and together we share 2.68% of our DNA. Subjects A and B, who are first cousins, twice removed, share 12.5% of their ancestry and 3.64% of their DNA.

Confused yet? Good. This particular matching produced 19 matches and only three of whom I share any DNA at a significant level. The great difficulty in determining which side these relationships originate can only come through comparing to others that are related to me and these two cousins from one side of the family and not the other.

Fortunately, I have two individuals from each side of the family to do this comparison. Unfortunately, the two related to me through my paternal grandmother did not match these 19 people. The two subjects related to Subject A and B through my paternal grandfather’s mother each matched one individual. From the 19 matches, only two can be placed into a specific lineage. The others will require further research.

Half Cousin/Second Cousin

Since my father had half-sisters and no full siblings, I tested my half cousin who is also a second cousin to Subject A in the preceding example. Their match, which is completely New England Colonial, produced 17 individuals in common – seven of these match me.

Half Cousin/Second Cousin Once Removed

Using this same half cousin, I repeated the exercise with our common second cousin, once removed. His great-grandmother was the sister of our grandmother. By comparing the two individuals, I was able to determine that they had 12 individuals in common and four of these match me.

Second Cousins

Although we share no Colonial New England lines we have some Colonial New Jersey and Pennsylvania lineages, my common paternal second cousins produced a sizable number of matches. The three of us share great-grandparents, and we descend from three of their five children. These two cousins had 28 matches in common – four of which I shared. I would have expected that we would have shared more, but we don’t for some reason.

Second Cousin/Second Cousin Once Removed

The next comparison was between my second cousin and my second cousin, once removed.  They are second cousins, once removed and share a Colonial New England ancestry.  Both descend from my grandmother's two sisters.  The two share 10 matches in common with only three that matched me.

Second Cousins/Fourth Cousins, Once Removed

My second cousins and I share a fourth cousin, once removed, and since one of the second cousins shares a larger than normal amount with her, I thought it might prove interesting if we see how many they match; some of these individuals could be my relatives as well.

Needless to say, the pair matched four individuals. One of these is a known fourth cousin. Because I do not share any autosomal DNA with this fourth cousin, once removed, I have no matching DNA with any of the four – including the other fourth cousin – who also matches her. Of the 16 folks in our family study based on my surname lineage, only these two women match this fourth cousin, once removed.


What I’ve learned from this exercise is that I can possibly discover non-DNA relatives in 23andMe’s database. While there is always a chance that the matches that my cousins match are not related to me personally, there are those who would be.

While many of the matching segments are very small, I probably will not pursue some of these personally, as I’ve found that trying to determine relationships with the smaller matches has been an exercise in futility. While I will share with anyone who wants to share, I am currently only actively tracking individuals that share at least .20% of their genome with my family members.

This was a fun exercise and it renewed my interest in my 23andMe matches. I’ve become a little stagnant with my autosomal pursuits as of late. This effort has infused a bit more vigor in this regard. Try it and see if you can find possible non DNA relatives in the 23andMe database.

Wednesday, March 6, 2013

Who Do They Think I Am - A Look At Four Autosomal Analyses

Since a number of genetic genealogists have already participated in the exercise of analyzing their results from the various autosomal companies, I have decided to look at mine as well. To see what others have discovered, see the posts by CeCe Moore and Roberta Estes. In my analysis, I will only look at the results from four commercial entities that provide autosomal results: National Geographic’s Geno 2.0 Project, Family Tree DNA’s Population Finder,’s AncestryDNA, and 23andMe’s Ancestry Composition.

Each of these four companies provided different results and I will compare these in light of what I know concerning my own ancestry from the last 500 years. Attempting to assign a person to a population is less difficult for someone who has a homogenous ancestry than it is for someone who is admixed from divergent populations. Some of the services will assign a primary population while others look at the constituent parts of one’s genetic background and provide an analysis of the segments.

Regional Populations

Another problem in comparing the results is that the various companies use different reference populations. In addition, regional populations are not consistent. For Europe (where all of my known ancestors hail), 23andMe classifies four regional populations: Northern European, Southern European, Eastern European, and Ashkenazi.

FTDNA’s European regions are identified as Western European, Northeast European, Southeast European, and Southern European. AncestryDNA features more European regions and these include British Isles, Scandinavian, Central European, Eastern European, and Southern European.

The Geno 2.0 project assigns local results based on a mixture of a variety of world regional populations with only two that are predominantly European in origin: Mediterranean and Northern European; however, the Mediterranean segment classification is not limited to Europe. With only two regional populations assigned to Europe, it is difficult to compare the Geno 2.0 results with the others – but we will get to this later.

My Ancestry

To the best of my knowledge, the following chart illustrates the nature of my ancestry within the last several hundred years. While I can take some lines back to the 1500s and beyond, others can only be traced satisfactorily to the early 19th century.

Primarily, I am English (38.28%) and German (31.25%). Scottish, Welsh, and Swiss are represented by each constituting 6.25% of my ancestry. My Scots-Irish, Irish, and French ancestries each contribute 3.13% of my lineage. My French ties come from the former province of Dauphiné in southeast region of the country.

Finally, my least represented known ancestry is of Norman stock from the Isle of Jersey. Two New England families on my father’s side constitute this lineage. My Gustin (formerly known as Jean de la Tocq) line and associated families are from St. Ouen’s parish and my Gavitt/Gavey line and related families hail from St. Saviour’s parish.

While I do not have any personal knowledge of Dutch ancestry, there are a number of residents of the Netherlands that match my mother on 23andMe with percentages that are consistent with third and fourth cousins. The origin of these connections has not yet been determined, but probably will show as one of my lines previously believed to be German. In addition, it is thought that my Maneval line, which originated in Dauphiné, may have intermarried with Italians in Piedmont.

National Geographic’s Geno 2.0 Project

In the Geno 2.0 project, the various reference populations are viewed from their specific admixture. Since my ancestry is European, we’ll concentrate on those references for this discussion. There are 12 reference populations from Europe and include the following ethnicities: British, Bulgarian, Danish, Finnish, German, Greek, Iberian, Romanian, Russian, Russian Tartars, Sardinian, and Tuscan.

All of the above populations have Northern European, Mediterranean, and Southwest Asian components. Certain populations (Bulgarian, Finnish, Romanian, Russian, and Russian Tartars) also carry segments from Northeast Asia. Depending upon the reference population’s geographic location, the majority of the segments were either Northern European or Mediterranean.

Mediterranean is also found as the majority component in the following non-European populations: Egyptian, Georgian, Iranian, Kuwaiti, Lebanese, Northern Caucasian, Puerto Rican, and Tunisian. Mexican-Americans also have a sizable Mediterranean component; however, Native American is their greatest percentage.

Other regional reference markers that are not found in the European reference populations are Southeast Asian, Native American, Oceanian, Subsaharan African, and South African. For an overview of the reference populations used in this study, go to

For my results, my Northern European component at 41% is less than the Northern European reference populations of Finnish (57%), Danish (53%), Russian (51%), British (50%), and German (46%). My Mediterranean component (39%) is greater than that which is found among German (36%), British (33%), Danish (30%), Russian (25%), Russian Tartar (21%), and Finnish (17%). It is also considerably less than more southerly European populations from Sardinia (67%), Tuscany (54%), Greece (54%), Iberia (48%), Bulgaria (47%), and Romania (43%).

Since European populations also have Southwest Asian genetic components, my 19% is slightly higher than most of Geno 2.0’s European reference populations; however, it appears to be more closely aligned with Eastern Europeans such as Russians (18%), Romanians (19%), Bulgarians (20%), and Russian Tartars (21%); however, I do not have any Northeast Asian markers, which are characteristic of all of these populations.

I have included a chart of four reference populations compared to my results. Included in those four are the primary (German) and secondary (Tuscan) reference populations as determined by Geno 2.0. I have added two additional populations (British and Danish) for comparison purposes.

Geno 2.0 lists German as my primary reference population. I am in agreement with this as I have a large percentage of German ancestry and an even larger percentage of English. When one remembers that Saxon, Angle, Jute, Frisian, Viking, and Norman invasions occurred on British soil, Germanic segments would have contributed greatly to this ancestry.

According to Geno 2.0, “This reference population is based on samples collected from people native to Germany. The dominant 46% Northern European component likely reflects the earliest settlers in Europe, hunter-gatherers who arrived there more than 35,000 years ago. The 36% Mediterranean and 17% Southwest Asian percentages probably arrived later, with the spread of agriculture from the Fertile Crescent in the Middle East over the past 10,000 years. As these early farmers moved into Europe, they spread their genetic patterns as well. Today, northern and central European populations retain links to both the earliest Europeans and these later migrants from the Middle East.”

Geno 2.0’s secondary population for me is Tuscan. Even eyeballing the results tells me something is amiss. While I have a Mediterranean percentage that is larger than the Northern European references, it is not comparable with those from Tuscany. I have included British and Danish references in the above graphic and they appear to be more in line with secondary and tertiary populations.

If I were to score the populations based on the total percentage differences of the three categories of Northern European, Mediterranean, and Southwest Asian, the Tuscan reference is not as close as the British and Danish references. I have a total point difference of 10 with the German reference; however, the Tuscan population has a 30 point spread.

British, which is logical from what I know of my own ancestry, only has 16 points of difference, while Danish is further removed with 24 points of difference – still less than the Tuscan example. While I would be in agreement with the Germanic identity, I am not in agreement with the comparison to Tuscan populations.

Family Tree DNA’s Population Finder

When I first received my Population Finder results, I immediately dismissed these because of the inclusion of 8.42% Middle Eastern ancestry. My Western European ancestry was reckoned as being 91.58%. Knowing that my lineages were all European, I could not see where Middle Eastern segments could exist within the past 500 years; any Middle Eastern ancestry would certainly been too far removed to show in my analysis. Since receiving the Geno 2.0 results and seeing how pervasive Mediterranean and Southwest Asian segments were across all European populations, I have rethought my original opinions on these results.

Since populations are more complex than I originally thought, I am more inclined to view the Middle Eastern segments as either part of what is identified by Geno 2.0 as either Mediterranean or Southwest Asian in origin. This remains to be seen and since neither service provides a chromosome by chromosome analysis, it is impossible to see if there is a correlation.’s AncestryDNA

Ancestry’s analysis has me baffled, as they have assigned 21% of my ancestry to Eastern Europe. While I have a slight amount of my overall lineage traced back to Ukraine, it was 38 generations in the past and its overall impact on my autosomal results should be negligible.

Although not all of my ancestors are represented by the pins on the map shown below, the ones that are present show the predominance of my heritage coming from the British Isles and Central Europe. None are found in Eastern Europe. While I would love to lay claim on some recent Slavic ancestry, I cannot and I question the results as reported by Like Geno 2.0 and FTDNA’s Population Finder, Ancestry does not plot the results by chromosome.

23andMe’s Ancestry Composition

Introduced in December 2012, I will have to admit that 23andMe’s new feature is far and above the competition in accuracy based on my known ancestry. In the previous incarnation called Ancestry Painting, 23andMe’s ancestral analysis was pretty Spartan. My results were, in a few words, pretty vanilla – or in the color schemes used at the time – completely blue.

The new Ancestry Composition feature fine tunes these results with additional global populations going beyond their original European, Asian, and African classifications to the expanded European, East Asian/Native American, Middle Eastern/North African, South Asian, Sub-Saharan African, and Oceanian regional populations. In addition, several sub-regional populations were also added.

23andMe also defaults to a standard estimate of your populations and allows you to determine if you want to be more speculative or more conservative in your population estimates. I’m ready to go for broke (read “reckless abandon” for me) and completely rely upon the speculative results as it gives me more options.

While these results remained 99.7% European, some additional colors were added to my ancestral spectrum. These were very small by comparison with 0.1% each for Native American, North African, and South Asian. The results could be regarded as noise or just very small segments of my ancestry.

With two of these populations occurring at the same segment as my mother, I have a tendency to believe that they may be accurate – but very persistent and fairly distant markers. She shares the Native American and North African segments. Therefore, the Southeast Asian must come from my father. How they fit into my ancestry, I haven’t a clue. I would have thought that my father’s side had more of an opportunity to have Native American blood, as a majority of his ancestors were in the colonies over a hundred years prior to my mother’s first immigrants.

One thing that I believe is incorrect is the assignment for my X chromosome as being “British and Irish.” Having already phased my X as coming primarily from my maternal grandmother (see my previous post on this subject), I already know that her ancestry was 87.5% German and 12.5% French; however, the contributors to her X chromosome were all German.

Outside of this misidentification, I am pleased with how 23andMe assigned the various populations. My German ancestry is somewhat underreported; however, I am assuming that most of what came from my Teutonic predecessors is found under the “Nonspecific Northern European” category. While not having any known Sardinian (0.3%) or Balkan (0.2%) ancestry, I checked with my mother’s results and found that she only shared the Balkan markers. She also had a chromosome that was nearly all Italian which I did not inherit. This may indicate the supposed Italian ancestry from Piedmont.

The Sardinian must come from my father; however, his ancestry was primarily from the British Isles. There is one possibility though. My grandfather’s sister’s middle name was the Italian surname of Marcelli. Unfortunately, we have no clue why the second child of this family was named Essa Marcelli Owston. Was she named for a Sardinian or Italian ancestor or a friend of the family? Of my great grandparents’ five children, this is the only name that cannot be traced to a family member or a friend of the family. Alas, this is another mystery that hopefully can be solved at some time in the future.


Of the four autosomal services, I would have to say that 23andMe has the best analysis and it lines up closely with my known ancestry. It is the only service that drills down to the sub-regional populations and gives you the opportunity to speculate or be conservative about the analysis. It is also the only service that provides a chromosomal analysis. With the current price at $99, if you are looking for an inexpensive ancestral analysis, 23andMe is the route to consider.

Wednesday, January 30, 2013

Book Review: The Surnames Handbook

I’ve never met Debbie Kennett, but I feel that I have personally known her for several years. My first encounter with the author of The Surnames Handbook: A Guide to Family Name Research in the 21st Century came after I joined the Guild of One-Name Studies in 2011. Her helpful responses to me and others on the Guild’s list and related Facebook pages specifically helped me in the direction of pursing my own one-name study. Much of the advice that she personally offered is now available in book form from The History Press.

Frankly, I don’t know how she does it, but with her activity with the Guild as well as participating online with the International Society of Genetic Genealogy (ISOGG), conducting her own her own one-name study (ONS), and managing a number of DNA projects – I am impressed that she has the time to write such a thorough volume. I imagine that the old adage rings true, “If you want something done, ask a busy person.”

While this edition deals primarily with surname research in the British Isles, it is very thorough in this undertaking; however, where she can provide information for research in other geographic regions, Debbie has added these data to the book. Being that my own ONS is traced back to England, I found this book and her advice extremely helpful.

The book sets the stage with a forward written by Derek Palgrave who is president of the Guild of One-Name Studies. Debbie then jumps head first into providing the necessary definitions – including one that would be specifically helpful for American audiences who may not be able to discern differences between Great Britain, the United Kingdom, and the British Isles. Her definitions on surnames and forenames also set the stage for what follows.

The book contains ten chapters of narrative. Although each provides extensive information, they are written in a style that can be easily understood by the average reader – an attribute that is not always found in other volumes dealing with similar subject matter. Despite an intense amount of research that has contributed to The Surnames Handbook, the book transcends the theoretical realm and contains a very practical approach. Anyone who is considering surname research – no matter how much experience he or she has with the name of choice – will find something that will contribute to his or her own study.

Every chapter is complete with Internet URLs that point to specific web sites and databases that will aid in accessing additional specific information. Seven appendices at the end of the book provide innumerable Internet resources for further study. While I purchased the print version from, I would recommend a digital copy to get the full and immediate effect of these online resources.

The ten chapters are as follows:

1. The History of Surnames
2. The Classification of Surnames
3. Variants and Deviants
4. Surname Mapping
5. Surname Frequency
6. Has it Been Done Before?
7. Laying the Foundations: the Key Datasets
8. Surname Origins: Pre-1600 Resources
9. DNA and Surnames
10. One-Name Studies
From the very first chapter, I learned something new. Her Surname Origins chapter provided me information about Lay Subsidies that helped me develop a new theory concerning my own surname’s source, as I was able to find similar names in the areas where my name had ramified. I am currently doing additional research regarding this theory.

While she draws from her own research and the Cruwys ONS, she does not limit her illustrations to her own experiences. Aptly, Debbie incorporates examples from others’ research in tracing a surname. In her final chapter, she provides an in-depth case study of her own ONS. I find it helpful to envision what others have accomplished in determining what may contribute to my own research.

The biggest surprise was that Debbie began her own ONS in 2002. From the depth of her knowledge and her constant and helpful advice, both inside and outside this work, I would have assumed that she had been researching surnames for several decades. Her writing exudes her passion for surname research.

With this book, you will gain practical knowledge of the following: the development of surnames, the differences between surname variants and deviants, how to map your surname and compute its frequency, where to research the surname in the medieval period, how to conduct a related DNA study, and how to proceed with a one-name study.

As previously mentioned, The Surnames Handbook: A Guide to Family Name Research in the 21st Century provides several appendices at the end of the book. These invaluable resources are as follows:

A. Genealogy Websites
B. Surname Websites
C. Lay Subsidy Rolls
D. Organisations and Journals
E. Linguistic Resources
F. Place-Name Resources
G. Population Statistics

If you are considering studying a particular surname – especially if that surname originated in the British Isles, you would be remiss by not having this important volume as part of your library. I highly recommend The Surnames Handbook: A Guide to Family Name Research in the 21st Century.