My letter in Family Tree Magazine about "genetic homeland" stories

The August 2014 issue of Family Tree Magazine includes a letter I wrote in response to two stories in their July issue which claimed that it is possible to identify someone's "genetic homeland" from a DNA test. There was not space in the magazine to include the full text of my letter and the editor has kindly given me permission to reproduce the full letter here.

In your July issue you published two articles which claimed to show that it is possible to pinpoint your "genetic homeland" a thousand or more years ago by taking a simple DNA test. It would indeed be wonderful if a DNA test could give us this information but sadly it is not possible. 

The first story “DNA: find your ancestral home” (p9) referred to a new autosomal DNA test developed by a company called Prosapia Genetics. They claim that they are able to pinpoint someone’s genetic homeland one thousand years ago and that their test is “accurate to home village with a time resolution of the past 1,000 years”. The underlying research on which this test is based was published in a scientific journal (Elhaik et el 2014, Nature Communications 5: 3513). However, the researchers were only able to place 50% of people within 450 kilometres of their country of origin, which is hardly the level of precision claimed. Furthermore the research focused solely on the present-day country of origin and made no attempt to determine an ancestral origin one thousand years ago. Such a method is best thought of as human provenancing – finding the location where an individual’s genotype is most likely to be found – not a method for inferring ancestry. Indeed, if you go back one thousand years you have in theory about 35 billion ancestors, although you actually inherited DNA from only a small, random subset of those ancestors. Identifying a single location as the “genetic homeland” of either all your pedigree ancestors or just the DNA ancestors would be a meaningless exercise. The International Society of Genetic Genealogy received a number of reports from dissatisfied customers of Prosapia Genetics, many of whom had received bizarre results placing their "genetic homeland" in the middle of a river or ocean. Fortunately they were able to get refunds from PayPal. 

Dr Tyrone Bowes, the author of the second article "Routes to roots" (pp14-18), claims to be able to tell his customers when their ancestors arrived in Britain and where they came from based on recurring surname matches received as part of a commercial Y-chromosome DNA test. DNA testing is a very useful tool for the genealogist, and Y-DNA matches can often provide clues about our recent origins. However, Y-DNA results should always be interpreted in combination with genealogical and historical records. While a Y-DNA test is very good at indicating whether or not two people share a recent male-line ancestor, it is much more difficult to determine precisely when or where that ancestor might have lived. For example, a match on 34 out of 37 markers could indicate a shared ancestor who lived 200 years ago or 2000 years ago, and there is no way of determining the precise timeframe. Furthermore, surnames did not become common in Britain one thousand years ago, as is claimed. They were introduced into Britain with the Norman Conquest but the adoption of surnames was a gradual process. While most English people had acquired surnames by the fifteenth century, surnames were not adopted until the nineteenth century in some parts of Wales. In the Highlands of Scotland the clan system survived until the eighteenth century, and people adopted the name of the clan rather than using an hereditary surname. Even when surnames are passed on through the fatherline the link between the Y-chromosome and the surname is often broken as a result of illegitimacy, cuckoldry, adoption or name changes. In addition, there is an inherent American bias in the commercial databases. Consequently Y-DNA matches will often tell us more about non-paternity events in Colonial America in the last 400 years, rather than a person’s origins in the British Isles. All these factors need to be taken into account when interpreting DNA results. 

The mutations that determine haplogroups (the deep-rooted branches of the human Y-DNA tree) did indeed occur at a specific time and place several thousand years ago, but determining when and where that happened is a different matter entirely. We are reliant on making inferences from the DNA of living people. However, the current distribution of haplogroups differs from each of the distributions at different times in the past. The changes occur due to migration and the randomness of genetic drift. As more ancient DNA samples become available it might one day be possible to provide some answers, but we are not there yet and it is unlikely that we will ever be able to "precisely reconstruct our ancestral journey". 

Readers wishing to understand more about the legitimate uses of DNA testing for genealogy and the limited inferences that can be made from deep ancestry tests might like to refer to the new “Debunking genetic astrology” website that I have worked on with my colleagues at University College London: www.ucl.ac.uk/mace-lab/debunking. In particular readers might like to look at the page on dubious commercial claims (www.ucl.ac.uk/mace-lab/debunking/companies) where the genetic homeland stories are discussed in greater detail.

The editor also included in the August issue of Family Tree Magazine responses to my letter from Vladimir Makarov of Prosapia Genetics and Tyrone Bowes, the creator of the Irish, Scottish and English Origenes websites. Unfortunately, neither letter addressed any of the issues I'd raised. Vladimir Makarov argued that his reports do reflect ancient origins simply because the reference populations he uses are "totally agnostic of political boundaries". He failed to recognise that these reference populations are themselves possibly admixed and do not necessarily represent the population in the same location one thousand years ago. Tyrone Bowes went into great detail about a case report that he'd compiled for a Mr Valentine which purported to show a link with the McGregors. It seems that his entire dating method has been based on this single case. Numerous scientific studies have of course demonstrated that mutations occur at random, and any attempt to investigate the validity of matches must take into account the uncertainties in the TMRCA (time to the most recent common ancestor) calculations. My points about differing times of surname adoption and non-paternity events remained unanswered.

For further information about Prosapia Genetics and the case reports offered by the Irish, Scottish and English Origenes websites see my two earlier blog posts:

- Driving in the wrong direction with a dodgy DNA satnav (a critique of the test from Prosapia Genetics)
- A look at the genetic homeland case reports from English Origenes, Irish Origenes and Scottish Origenes

© 2014 Debbie Kennett

A look at the genetic homeland case reports from English Origenes, Irish Origenes and Scottish Origenes

I've had a number of people writing to me in the last few months to express concerns about the genetic homeland case reports offered by Tyrone Bowes through his English Origenes, Irish Origenes and Scottish Origenes websites. The reports have also been the subject of much discussion in various groups and forums (see the links at the end of this article). I've now spent some time reviewing the methodology and the case reports, and I share the concerns of my correspondents so I thought would take this opportunity to highlight some of the problems.

Tyrone Bowes claims to be able to use "modern science" to pinpoint the place of origin of one's patrilineal ancestors one thousand years ago based on the results of a 37-marker Y-DNA test from Family Tree DNA. The distribution pattern of the surnames that appear in the person's match list is used to identify the "genetic homeland", which is defined as "the area (within a 5 mile radius) where one's ancestors lived for hundreds if not thousands of years. It is the area where one's ancestors left their mark in the history and place names of that area and in the DNA of its current inhabitants."  I understand that the reports cost in the region of  $300 a time. A free consultation is provided to determine whether or not it is possible to pinpoint a "genetic homeland". An 80% success rate is claimed for the Irish and Scottish reports, but no claim is made for the English case studies.

As far as I am able to establish the methodology used for the reports has not been legitimised by publication in a peer-reviewed scientific journal. An article by Tyrone Bowes entitled "Using Y Chromosome DNA Testing to Pinpoint a Genetic Homeland in Ireland" was published in April 2013 in the Surname DNA Journal. This journal was founded in January 2013 by Brad Larkin, a genetic genealogist who runs the Larkin DNA Project. Only five articles have been published in the journal to date, two of which have been written by Brad Larkin, and a third article has been contributed by a Larkin cousin. Although I am given to understand that the articles are reviewed prior to publication, the journal has no named editor and no editorial board so we cannot be certain that the people who are reviewing the articles have any expertise in the subject matter they are commenting on. Brad Larkin and Tyrone Bowes appear to have a business relationship. They jointly founded the Genetic Homeland website in March 2013, and this website is advertised prominently on the home page of the Surname DNA Journal.

The article in the Surname DNA Journal outlines Tyrone Bowes’ hypothesis that "Using commercial Y chromosome DNA testing, the Family Tree DNA database, the 1911 census of Ireland, Microsoft Excel, customized mapping software for surname distribution mapping, ordinance [sic] survey Ireland maps, and Google Earth it is possible to explore the relationships between a test subjects surname, and the surnames of his genetic matches to pinpoint the Genetic Homeland of an individual, and find evidence of their ancestors presence in the placenames and DNA of the areas current inhabitants." Eight case studies are presented to illustrate the methodology. However, the author makes no attempt to test the hypothesis scientifically. In the discussion it is stated that "the pinpointed 'Genetic Homeland' can be verified by Y chromosome DNA testing of people with the test subjects surname in the identified area". It is surprising, therefore, that such testing was not done for all the surnames in question to establish whether or not the hypothesis had any validity. It is claimed in the article that one person with the surname Bowes was tested to confirm the "Genetic Homeland of Clan Bowes" which is supposedly pinpointed to "an area centered upon modern day Abbeyleix in county Laois". However, this conclusion is disputed by Martha Bowes, the administrator of the Bowes DNA Project.

Despite the lack of scientific evidence in support of the methodology it seems that a number of people have ordered the genetic homeland case reports, and selected reports have been made available on the various Origenes' websites. It seems to me that the methodology is fundamentally flawed, and is based on a number of false assumptions. I've summarised below some of the main problems:

1) While matches with other surnames can often provide valuable genealogical clues, the claim to pinpoint a genetic homeland with such precision is not supported by the evidence provided. The technique does not account for the inherent uncertainty in the estimates of the time to the most recent common ancestor (TMRCA). The calculation of a TMRCA is based on probability, and there are many variables such as sample sizes and mutation rates. Consequently TMRCA is not an exact science. It does not provide a precise point in time (eg, seven generations ago) but a probability distribution  – a range of time in which the common ancestor might have lived. For example, a match on 34/37 markers could indicate a common ancestor who lived 200 years ago or two thousand years ago. It is therefore important that DNA evidence is considered in combination with genealogical evidence and not in isolation.

2) The Origenes' method takes no account of the biased nature of the Family Tree DNA database. Around 70% of FTDNA customers are thought to reside in the United States, and matches with other surnames may often reflect non-paternity events in the US rather than the origin of a surname in the British Isles. This point is nicely demonstrated in Howard Mathieson's critique of the Irish Origenes' case study of the Kiely surname. Furthermore, the FTDNA database has inevitable gaps, and many British and Irish surnames, particularly lower frequency surnames, are not yet represented.

3) The Origenes' reports do not appear to make any attempt to verify the SNP status of the people in the match lists whose surnames are used to pinpoint the "genetic homeland". SNP testing is important when investigating matches with other surnames in order to ensure that the matches are not false positives. Two men can have matching Y-STR results, but if they do not share the same SNPs they will belong on different branches of the Y-DNA tree and will not share a common ancestor within the last few thousand years. This problem occurs as a result of convergence. Although 37-marker results are most commonly affected the problem can still occur with more distant matches at 67 markers.  Convergence is a particular problem in haplogroup R1b, the most common haplogroup in the British Isles which is found at a frequency of about 70% in England and over 80% in Ireland.

4) The assumption has been made that the geographical overlap of the matching surnames is an indicator of the "genetic homeland". However, it is conceivable that many groups of randomly selected surnames would overlap purely by chance but no attempt has been made to rule out this possibility.

5) The methodology is based on the hypothesis that "genetically recurring surname matches" provide a snapshot of one's "medieval ancestor’s neighbours". If the theory is correct, then the methodology needs to be applied consistently, but a close examination of the case reports reveals many inconsistencies. Sometimes recurring surnames are omitted for no apparent reason whereas in some of the case reports singleton matches are included, even though the technique requires that singletons should be omitted because they are claimed to be indicators of non-paternity events. For example, in the Patterson case study on the Scottish Origenes website it is apparent that Mr Patterson has recurring 67-marker matches with a wide variety of different surnames. Only the closest matches with a genetic distance of three or less are considered important enough for consideration for this report. Furthermore, only a few select surnames (Henderson, Stewart, Chisholm, McKay, McLean, Logan, and McDonald) are cherry-picked for inclusion while many of the other recurring surname matches (Norton, Stephenson, Turner, Johnson, Edwards, Tate, Rock) are excluded, presumably because the distribution will not support the proposition that Mr Patterson's "ancestral genetic homeland is centred upon Knockbain on the Black Isle", just north of Inverness. The opposite problem applies to the case report for Mr Henderson who inconveniently only had matches with other Hendersons at 67 markers. His matches at 37 markers were used instead in combination with more distant 37-marker matches found on Ysearch. For this report all the matching surnames were taken into account, including those surnames which only occurred once in the match list. Similarly in the Bennett case study on the English Origenes website the surname French is included in the report despite the fact that the surname only appears once.

6) The reports show no understanding of the evolution of place-names, and the evidence used in support of the genetic homeland stories is implausible at best. For example, in the Bennett case study we are told that "The Bennetts of Somerset cluster near the town of Burnham on Sea close to the Bristol Channel". We are further told that "the local placenames that reflect the ancestral link of the Bennetts and their genetic cousins with the surrounding area" include Bennett road, Lockswell, Locksway, Seymour road, Seymour Court, Coat (village), and Coate farm. Place-names can of course be very informative but most roads have been built and named in the last century or so, and road names are therefore highly unlikely to correlate with the presence of a surname in the locality one thousand years ago, especially in a seaside town which has probably had an influx of residents from many different parts of the UK.

DNA testing and surname distribution mapping are both very powerful tools for a surname study but they should always be used in combination with genealogical and historical records, and the results should be interpreted with caution. In order to determine the origin or origins of a surname it is necessary to map a surname at different points in time to establish continuity. Ultimately there is no substitute for a carefully conducted worldwide surname study which makes use of all available records from the beginnings of surnames to the present day.

Further reading
For further discussions on the limitations of the Origenes' methodology see:
- My letter in Family Tree Magazine about "genetic homeland" stories (August 2014 issue)
- A Review of Irish Origenes' Bowes Case Study‎ by Martha Bowes, administrator of the Bowes DNA Project and one-name study
- Origenes case study reviews by Howard Mathieson. See in particular Howard's article Can the Distribution of 19th Century Farmers Be Used To Identify a Surname's Genetic Homeland?
 - Bowe research methodology queried - a letter from Fíona Tipple in the June 2014 issue of the Genealogical Society of Ireland's Gazette (page 2).
- A civil discourse on Irish Origenes' methods, a discussion on the Anthrogenica forum
- Irish Origenes  and Irish Origenes – the next generation, discussions on the Guild of One-Name Studies' mailing list
- Critique of “Grace an English Origenes Y-DNA Case Study” of 24th September 2017 by Dr. Tyrone Bowes A review by a dissatisfied customer

A list of surname mapping resources can be found in the ISOGG Wiki.

I have discussed the available sources and the techniques for surname mapping at length in my Surnames Handbook (History Press, 2012).

For information on the methodology used in a one-name study see the website of the Guild of One-Name Studies.

See my Sense About Science blog post Sense About Genealogical DNA Testing for a summary of the legitimate inferences that can be made from DNA tests.

© 2014 Debbie Kennett