DNA Matching

Our Clan has an active project to help you understand your ancestors going back well beyond what can be achieved with genealogy. The original advisor to the project was Dr David H MacLennan OC, a medical researcher and retired professor. A a set of “Questions and Answers” between David and Melanie MacLennan about DNA testing can be found from the links below. David’s most distant known ancestor, George McLennan – i1121 in the Clan database – was born in Redcastle in Killearnan parish in 1776. His son, George McLennan 1810-1883, migrated to Canada in 1842.

The Y-Chromosome is carried only by men who inherit it from their fathers. Y DNA-matching is therefore only done on men. As surnames in Europe are typically patrilineal in descent the Y-Chromosome can be used to identify men who share a common ancestor. As women do not carry a Y-Chromosome, females who wish to participate require a male MacLennan to provide a sample. The DNA test itself involves a simple swab on the inside each cheek.

To study our maternal line, mitochondrial DNA is sequenced, since we all (men and women) inherit our mitochondria only from our mothers. Because mitochondrial DNA is very short compared to Y chromosome DNA, we have relatively few maternal markers to be tested. Thus the resolution for maternal lines is not as great as for paternal lines.

The DNA testing companies operate in an evolving market. There are a number of offerings in the market for Y chromosome DNA testing, but the only one that should be considered for entry into genetic genealogy through analysis of your “STR” markers is Family Tree DNA (FTDNA). This is because they have a huge number of individuals in their database and have virtually captured the British market and the US, Canadian, Australian (and probably NZ) markets for people whose ancestors emigrated from the British Isles. Since the objective is to compare your DNA directly with everyone else in a database with the largest number of candidate relatives, you want to be sure that you are in that largest database. FTDNA has a superb customer service track record in this area.

A discounted 67-marker FTDNA kit is available to Clan members from FTDNA’s UK representative Alasdair F Macdonald – please go to: www.yourscottishancestry.com/section.php/63/1/clan_maclennan

Alasdair F Macdonald is an Administrator of the “Clan MacLennan DNA Project” at FTDNA.  Contact Alasdair F Macdonald via www.yourscottishancestry.com/contact.php

At the moment, there are 3 stages to DNA testing:

Advice from David H MacLennan, Toronto and Alasdair Macdonald: :

  1. The first is to obtain your STR markers (short tandem repeats). FTDNA offers several possible tests at different prices. The 37 marker test is deemed an introductory test.  It will identify patrilineal relatives within Family Tree DNA’s extensive database (if they have tested) as well as matching to other more distantly related test takers.  The 37 marker test though has limitations in terms of establishing the time frame when two individuals shared a common ancestor and the ability to weed out false positive matches. Therefore, if you can afford it now and if you intend to follow your testing through to a logical end, it will be cost saving in the long run to order the 111 marker test. However, you can upgrade from the 37 marker test to the 111 marker test at any point.
  1. The second stage in your DNA testing will be to look for a marker that a) defines your lineage b) will weed out false-positive matches and c) help to date when your lineage branched from the main line. Such markers are called SNP (single nucleotide polymorphism). The most recently formed in terms of age is called your ‘terminal’ SNP. Your ‘terminal’ SNP will change as you get more recently related matches with whom you share a different SNP.  Such SNPs help confirm linkage where documentary evidence is wanting and allow us to explore and connect to other test takers before commencement of parish records which in many cases start late in the Highlands.
    SNPs enable us to with a degree of confidence identity the timeframe to a shared ancestor within a few hundred years and confirm linkage to those who do have an establish pedigree due to being landholders, tacksmen or cadet lines who are recorded in traditional Highland genealogies. Confirmation with shared SNPs between test takers provides focus for research with a possibility of finding paper trails that link you. STR test and SNP tests will likely reveal matching to close genetic relatives bearing other surnames and clan names.  This is not unusual and simply reveals the reality of the nature of the ‘Clan’ in Highland society.
  1. There are two approaches to testing SNPs – a) SNP packs or panels and b) Next Generation Sequencing (NGS).
    a) For SNP packs or panels you might want to consider alternate companies. Yseq competes very effectively with FTDNA for these.  However, you would need to seek advice from a project administrator of what is the most suitable for your situation.
    b) With advances in technology and processing the more cost effective test and for longer term value is to take a Next Generation Sequencing. Such tests sequence all of the accessible regions of your Y chromosome. FTDNA offers the “Big Y-700” test and Full Genomes Corporation (FGC) offers the “Y Elite″ test. The tests cost similar in the range of $425-$450. An advantage of Big-Y-700 is that your matching will be within a very large database, while the Y-Elite has better coverage so will find more variants that can become SNPs.

    Why might people want to do Next Generation sequencing? First, we have only uncovered a fraction of all of the SNPs that can provide useful information on branch points in our pedigrees. The sequencing tests are turning up new and useful SNPs every day and they are being organized into the trees that eventually will give each of us a number of SNPs that define our unique recent patrilineal family. NGS testing is to be recommended.

When David did his FGC Elite Y chromosome sequence he found that I had 14 novel SNPs that could be tested against his 6 MacDonald and 2 McKenzie relatives. Alasdair MacLennan and Canadian David H MacLennan have 3 “terminal” SNPs that are not shared by their McDonald and McKenzie relatives creating a “MacLennan branch point”.

When Bruce McLennan took his Big-Y test with Family Tree DNA he matched Alasdair Macdonald and a group of other test takers in the Inner and Outer Hebrides, and the West Highlands including the MacNeils of Barra. They all track back to an individual called Ferchar of Bute who prospered on that Island circa 1266 AD. Ferchar (Farquhar) and his family originated as court officials and tax-gatherers (‘barons’) for the MacRuairis in Bute. This has all been made possible by new interpretation of the 1467 MS by Prof Ronald Black and the use of Next Generation Sequencing.

Why might people want to do Y chromosome sequencing? First, we have only uncovered a fraction of all of the SNPs that can provide useful information on branch points in our pedigrees. The sequencing tests are turning up new and useful SNPs every day and they are being organized into the trees that eventually will give us our terminal “bin”. When I did my FGC Elite Y chromosome sequence I found that I had 14 novel SNPs that could be tested against my 6 MacDonald and 2 McKenzie relatives. Alasdair MacLennan and Canadian David H MacLennan have 3 “terminal” SNPs that are not shared by our McDonald and McKenzie relatives creating a “MacLennan branch point”. If we had other Y chromosome sequences, we might find a recent MacDonald and a recent McKenzie branch point. Who knows?

Questions and Answers:

Part 1 What can we (MacLennan Clan members) learn from DNA-based genetic genealogy? Click here

Part 2 What can we (MacLennan Clan members) expect from DNA-based results? Click here

Further information about DNA-matching:

Educational material http://www.isogg.org/wiki/Wiki_Welcome_Page

Scottish Project www.electricscotland.com/webclans/dna_projectndx.htm

David H MacLennan

More about Dr David H MacLennan OC in Canadian Medical Hall of Fame- http://cdnmedhall.org/dr-david-h-maclennan