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Genealogical DNA Tests and Links Kathy Sztanko 17 th November 2017

Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

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Page 1: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Genealogical DNA Tests and Links

Kathy Sztanko

17th November 2017

Page 2: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Genealogical DNA Testing

A genealogical DNA test is a DNA-based test which looks at specific locations of a person's genome in order to determine both their ancestral ethnic groups and genealogical relationships by comparison with other results.

These different types of results are possible because different markers within the DNA change at different rates - ethnic markers change extremely rarely, family markers more frequently.

Page 3: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Uses of Genealogical DNA TestingA genealogical DNA test may:

● help to verify your family tree● provide helpful clues to inform the future direction

of your research● possibly help to break down long-standing brick

walls

It can’t provide you with an instant family tree

It’s value lies in the comparison process, so it’s important to test with a company that has a matching database and to have a good tree based on genealogical records to start with.

Page 4: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

What is a genome?

A genome is all of a living thing's genetic material, it contains around 20,000 genes (single molecules of DNA), packaged in 23 chromosomes which affect the characteristics of the organism

Human DNA is 99.9% the same between individuals, DNA tests look at the 0.1% that is different

Unless you are an identical twin, your genome is different from that of every other person on earth, in fact, it is different from that of every other person who has ever lived

Page 5: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Where does your genome come from?

Humans have 22 pairs of autosomal Chromosomes (which are the same in males and females), plus one pair of sex chromosomes that differ, being XX in a female and XY in a male.

During reproduction each cell copies itself then divides twice so each new cell contains half the normal number of chromosomes which combine with those from the other parent to produce a mixture of characteristics.

Page 6: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

What is DNA?A DNA molecule is a double helix, a structure that looks like a ladder twisted into a spiral.

Each rung of the ladder is made of two bases linked together in the middle. Bases are coded with the letters A,C,G & T. The length of a DNA molecule is often measured in "base pairs”.

When DNA replicates the ladder disconnects and makes a new partner, sometimes mistakes are made during this process and sections are duplicated or lost. These are the markers that are tested.

Page 7: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

DNA Stability and Haplotypes

Genealogical DNA testing looks at the portions of the DNA that have no known function. Generally these stretches of DNA remain unchanged from generation to generation.

But chance changes (called mutations) do infrequently occur and it is these changes that distinguish different lines of descent and determine how closely people may be related to each other.

It is estimated that the human Y-chromosome accumulates roughly 2 mutations per generation. Mitochondrial DNA mutations occur less frequently.

Page 8: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Haplogroups and EthnicityA DNA sequence that is passed on unchanged from one parent to a child is called a haplotype, these are the distinctive patterns used to establish genealogical links.

Haplotypes can be grouped into Haplogroups (broad population groupings which diverged thousands of years ago). Each haplogroup (or clade) is a group of similar haplotypes that share a common ancestor.

People with different haplogroups cannot be related.

Clades often have origins in particular geographical regions and are used to indicate ethnic origins.

Page 9: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Common ancestorsMale & female haplogroups are different and do not relate to one another in any way.

We all ultimately share a common male ancestor known as “Y chromosome Adam” and a common female ancestor known as “Mitochondrial Eve”.

These ancestors did not live at the same time and were not the only males and females around at the time.

But they are the only male and female whose DNA has come down to the current day.

Page 10: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Types of DNA test 1The first commercially available DNA tests for family historians became available in 2000 but were very expensive, since then testing companies have proliferated and prices dropped.

Y-DNA – traces paternal ancestry up the male line and is used for surname projects. It can only be taken by males.

Mitochondrial (Mt)DNA – traces maternal ancestry up female line. Mitochondrial DNA is carried by males and females but only passed on by females.

Page 11: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Types of DNA test 2Y-DNA & mtDNA cannot be used for ethnicity estimates, but can be used to indicate one's haplogroup.

Autosomal (at)DNA – traces both male and female lines and indicates potential cousins. Also known as Family Finder or Cousin Matching.

Page 12: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Types of DNA test 3

Page 13: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Which type of DNA test/company

The choice of test will depend on the questions that you want to answer.

A DNA test can be considered as an investment and the value of the test will grow as more people join the databases and you get more matches.

The two main companies are:

FTDNA – all three tests

Ancestry – autosomal only

Page 14: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

FTDNAFTDNA is the market leader for both Y-DNA & mtDNA testing with over 600,000 Y-DNA records & over 250,000 mtDNA records. It has the world’s largest Y-DNA & mtDNA genealogical matching databases.

They are the only company that allows complete integration of Y-DNA, mtDNA and autosomal DNA test results for genealogical purposes.

They host a wide variety of surname projects, haplogroup projects (Y-DNA and mtDNA) and geographical projects, currently 9,778 altogether.

Experienced and knowledgeable volunteer project administrators can often provide advice and help with the interpretation of results. Matches are more likely to be responsive and interested in genealogy.

The size of the Family Finder database has not been disclosed but is likely to be 500,000+.

Page 15: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

AncestryAncestryDNA has been responsible for taking DNA testing mainstream, and they now have the world’s largest autosomal DNA database.

The test benefits from a number of innovative and sophisticated features such as shaky leaf DNA hints integrated with family trees, DNA Circles, Genetic Communities and New Ancestor Discoveries. A subscription is required to access some of these features and to view the full trees of your matches.

The lack of a chromosome browser and matching segment data is a big disadvantage for advanced users who are interested in chromosome mapping.

Many of the people now taking the AncestryDNA test are lured in by the biogeographical ancestry reports, but are not interested in communicating about genealogy. However, the test is encouraging an interest in genealogy in a subset of this market.

Page 16: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Standard/sale pricesBoth companies offer reduced prices several times a year particularly around Thanksgiving/Christmas. Y-DNA tests are cheaper if you take a test through a research group.

FTDNA

● Y-DNA 25 marker $109 37 marker $169 (currently $129)67 marker $268 (currently $229)111 marker $359 (currently $299)

● Mitochondrial DNA full sequence $199 ($169)

● Autosomal $89 (about £68)(currently $59/£45)

Ancestry Autosomal £79+£20 p&p

Page 17: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Y-DNA Testing 1The Y-Chromosome is one of the 23rd pair of human chromosomes. Only males have a Y-chromosome, because women have two X chromosomes in their 23rd pair.

A man's male-line ancestry, can be traced using the DNA on his Y chromosome (the Y-DNA), because the Y-chromosome is transmitted father to son nearly unchanged.

A man's test results are compared to another man's results to estimate the number of generations in which the two individuals shared a most recent common ancestor, or MRCA, in their direct patrilineal lines. If their test results are very close, they are related within a genealogically useful time frame.

Page 18: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Y-DNA Testing 2Most of Y chromosome is very stable over very long periods of time but some areas “stutter” and a sequence of letters is repeated several times.

Y-DNA testing looks at these repeating sequences called Y-STR = Short Tandem Repeats.

These sequences are given names usually beginning DYS (DNA Y-chromosome segment) and a unique identification number. The number of times it repeats is the value of the marker, recorded as e.g. DYS 393 – 13 i.e. 13 repeats of a particular string. Occasional errors in copying mean this value changes very slowly over time.

Page 19: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Y-DNA Testing 3

A Y-DNA result will be shared by thousands of men across the planet showing that you share a common ancestor with them.

But if they don’t have the same surname then it is probably from before surnames came into use and therefore of no interest.

Y-DNA tests look at a fixed number of specific sequences ranging from the historical 12 markers to modern 111 but more usually 37 or 67.

Page 20: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Y-DNA Testing 4

The combination of numbers for all markers tested is called the Y-DNA Haplotype.

The difference in marker numbers is called the genetic distance e.g. 1 if 36 of 37 markers match.

Probability of common ancestor for distance 1 or 2 in 37 is as follows:

Generation 4 8 12 16 20 24 28

Percent (1) 58.5 88.95 97.44 99.45 99.89 99.98 100

Percent (2) 28.94 68.67 89.14 96.71 99.08 99.76 99.94

Page 21: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Non-Paternity Events

Sometimes a test will not match an expected family member, this is known as a non-paternity event (NPE).

There can be many reasons for this including:● faulty research● Illegitimacy / paternity fraud● use of an alias● change of surname● adoption

Page 22: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Why did I do it? Kearton family

Basil Kearton back toJohn Kearton ofThwaite, b. 16975xgreat-grandfather(7 generations back)

Robert Kearton(Kathy Sztanko) back to William Kearton ofHipswell, 17006xgreat-grandfather(8 generations back)

? Ancestral originKearton, 1200

Page 23: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Kearton Y-DNA Results

Page 24: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Most Recent Common Ancestor

Generations Probability Cumulative

1 0.220732 0.221

2 0.172009 0.393

3 0.134041 0.527

4 0.104454 0.631

5 0.081398 0.713

6 0.063431 0.776

7 0.049430 0.825

8 0.038519 0.864

9 0.030017 0.894

10 0.023391 0.917

11 0.018228 0.936

12 0.014204 0.950

13 0.011069 0.961

For a difference of 0 in 43 markers

Page 25: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Kearton Y-DNA Results

Page 26: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Subsequent Results

Basil Kearton back toJohn Kearton ofThwaite, b. 16975th ggf (7 generations back)

Robert Kearton(Kathy Sztanko) back to William Kearton ofHipswell, 17006th ggf (8 generations)

Jonathon Kirton of Canada, back to Anthony Kearton of Satron c. 1530 8th ggf

Now claims Anthony Kearton of Reeth b. 1500, 8th ggf

Now claims Anthony Kearton of Reeth b. 1500, 10th ggf

Now claims Cuthbert Kearton of Catterick b. c. 1500, 12th ggf

Page 27: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Most Recent Common Ancestor

Generations Probability Cumulative

1 0.220732 0.221

2 0.172009 0.393

3 0.134041 0.527

4 0.104454 0.631

5 0.081398 0.713

6 0.063431 0.776

7 0.049430 0.825

8 0.038519 0.864

9 0.030017 0.894

10 0.023391 0.917

11 0.018228 0.936

12 0.014204 0.950

13 0.011069 0.961

For a difference of 0 in 43 markers

Page 28: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Male Haplogroups

Y DNA testing provides a prediction of haplogroup based on Y STR markers.

Y chromosome Adam lived about 142,000 years ago and all subsequent population groupings have different codes from A (oldest) to T (most recent). There are about 20 major Y haplogroups.

The oldest, A & B are usually found in Africa, F is ancestor to all the European groups. In Britain the most common haplogroup is R1b1a2 (>60%) then I1 (considered a marker for Viking/Anglo-Saxon invaders), R1a (Norse/Viking) and several smaller groups.

Page 29: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Male HaplogroupsSubclades are further divisions of haplogroups using alternating alphanumerics e.g. R1b.

Kearton Haplogroup was originally given as R1b which was a little surprising as upper Swaledale is considered to have Viking origins. R1b has now been refined and renamed as R1b1a2.

R1b1a2 is the most common haplogroup in Europe and spread rapidly over a short space of time, a Deep Clade test can refine the haplogroup to reduce the number of potential haplotype matches.

Page 30: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Jonathan Kirton Deep Clade test

Deep Clade testing looks at different markers called SNPs (single nucleotide polymorphisms) to further refine the group. These occur when a single base changes e.g. T to A, they are very rare and perpetuate down to all descendants. Studying them produces a genetic tree of all mankind with each branch defined by a particular SNP.

Jonathan Kirton undertook a Deep Clade test which showed his Subclade was R1b1a2a1a1b4 also known as R1b-SNP L21+

Page 31: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Jonathan Kirton Deep Clade test

L21+ is about 4000 years old with Celtic origins possibly originating in Swiss/German/Austrian borders. It is the most common Y chromosome subclade of paternal lineages in the British Isles and is also significant in France.

FTDNA has interest group for this subgroup.

Page 32: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial Testing

Page 33: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial DNA testing 1The mitochondrion is a component of a human cell, and contains its own DNA. Individual cells contain as many as 2,000 mitochondria. Mitochondria do not pass data from one generation to the next but provide energy management for cells

Mitochondrial DNA is transmitted from mother to child, so a direct maternal ancestor can be traced using mtDNA.

The transmission occurs with relatively rare mutations, a perfect match to another person's mtDNA test results indicates shared ancestry between 1 and 50 generations ago (1300 years)- much less useful to your family tree.

Page 34: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial DNA testing 2

However it can be useful for particular problems.

Two famous cases were:● the identification of the Romanov Royal family

killed in 1917 by comparison with Prince Philip’s MtDNA, and

● the confirmation of the identity of the King in the Car Park as Richard III by comparison with the MtDNA of a Canadian-born carpenter, Michael Ibsen and Australian-born Wendy Duldig

Page 35: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial DNA testing 3

Both cases relied upon careful tracing of female lines of the family trees to descendants who could provide comparison samples.

Another use is to confirm links to particular haplogroups e.g. to confirm a maternal ancestor in British-India.

Page 36: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial DNA testing 4Mitochondrial DNA contains 16,569 bases in 3 regions: the less stable “control region” divided into HVR1 (HyperVariable Region) & HVR2, and the more stable “coding region”. Tests can cover just HVR1 & HVR2 or the full sequence. Full Genomic Sequence (fgs) mitochondrial DNA testing first became available in 2005 at a cost of £568.

Results are compared to the Cambridge Reference Sequence (CRS)(the first MtDNA ever sequenced in Cambridge which turns out to be a fairly common pattern found across Europe). Your results summarize differences from this standard in terms of base additions, deletions or changes.

Page 37: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Female HaplogroupsAll humans descend in the direct female line from Mitochondrial Eve, a female who lived in Africa between 100,000 and 250,000 years ago.

The Mitochondrial tree is divided into 26 different branches of her descendants (haplogroups) labelled A-Z (in order of discovery).

Most mtDNA results include a prediction or exact assertion of one's mtDNA Haplogroup.

Mitochrondial haplogroups were popularized by the book The Seven Daughters of Eve by Bryan Sykes, which explores mitochondrial DNA.

Page 38: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial Haplogroups

The seven "clan mothers" described by Sykes each correspond to one (or more) haplogroups:

● Ursula: corresponds to Haplogroup U ● Xenia: corresponds to Haplogroup X● Helena: corresponds to Haplogroup H● Velda: corresponds to Haplogroup V● Tara: corresponds to Haplogroup T● Katrine: corresponds to Haplogroup K● Jasmine: corresponds to Haplogroup J

The “daughters” actually lived thousands of years apart and there are now more identified.

Page 39: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Why did I do it?

I had recently read The Seven Daughters of Eve & was curious as to which group I belonged to/where my ancestors came from

My earliest maternal ancestor is Mary Lewis daughter of a farmer named Edward living on the Welsh borders – it might turn up something to help as tracing her tree won’t be easy!

Page 40: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial DNA Results

Page 41: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial DNA Results

Page 42: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial DNA Results

Mitochondrial haplogroup H (Helena) is a predominantly European haplogroup that originated outside of Europe.

It first expanded in the northern Near East and southern Caucasus between 33,000 and 26,000 years ago, and later migrations from Iberia suggest it reached Europe before the last glacial maximum (LGM) about 20,000 years ago.

Today, about 40% of all mitochondrial lineages in Britain and in Europe are classified as haplogroup H.

Page 43: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial DNA Results

An exact match on each test indicates a 50% chance of a common ancestor within the following time periods:

HVR1 52 generations (1300 years)

HVR1+HVR2 28 generations (700 years)

Full sequence 5 generations (125 years) and 90% in the last 16 generations (about 400 years).

I currently have 22 fgs matches all with a difference of 3 changes. I have no exact matches on “HVR1+HVR2” but 73 on HVR1 only.

Page 44: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Mitochondrial DNA matches

Page 45: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

MtDNA matches

Page 46: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Autosomal Testing

Page 47: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Autosomal DNA Testing 1

Autosomal DNA is contained in the 22 pairs of chromosomes not involved in determining a person's sex. Autosomal DNA recombines each generation, and new offspring receive one set of chromosomes from each parent.

Therefore, the number of markers received from a specific ancestor decreases by about half each generation - from parents (50%) and roughly from grandparents (25%) to about 3x great-grand parents (3.1%). (Inheritance is more random and unequal from more distant ancestors.)

Page 48: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Autosomal DNA Testing 2

The same applies to our siblings and cousins we share about 50% of our DNA with a full sibling or parent (except identical twins who share 100%), 25% with nieces/nephews & grandparents and 12.5% with first cousins.

By third cousins it is down to less than 1% and roughly 0.05% with fifth cousins; we may have over 500 cousins up to fifth cousins excluding those more than once removed.

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Page 50: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Autosomal DNA Testing 3Autosomal testing became available in 2009

Tests look at base pairs across entire genome with positions chosen at places where variants are known to occur, SNPs (single-nucleotide polymorphisms).

There have been about 10 million SNPS in all of human history.

SNPs are denoted with rs numbers or rsids which show their position in the chromosome.

Your raw autosomal DNA file will report all the rs numbers and their genotype e.g. AA, it runs to 20,000 pages as they test 700,000-900,000 SNPs.

Page 51: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Autosomal DNA Testing 4The usefulness of your results is comparison to those of other testers within the companies database.

Where two individuals share in common a number of consecutive SNPs, it can be projected that they share a segment of DNA at that part of their genomes. The number and size of shared segments can be used to predict the closeness of a relationship.

If the segment is longer than a threshold amount set by the testing company, then these two individuals are considered to be a match.

Page 52: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Autosomal DNA Testing 5The unit for segments of DNA is the centimorgan (cM) which measures how many SNPs that segment contains.

For comparison, a full human genome is about 6500 cM, I currently have 2363 matches ranging from 17 to 72cM. My predicted relationships to these matches range from “2nd to 4th cousin” down to “5th to remote cousin”

The tests are sensitive enough to show a match with most third cousins but may not show a match with up to 50% of fourth cousins and 90% of fifth, but some sixth to twelfth cousins may match due to random recombination.

Page 53: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Autosomal DNA Testing 6If you have identified all the descendants of your four times great-grandparents you may have something like the following (Debbie Kennett)First cousins 3

First cousins once removed 21

Second cousins 33

Second cousins once removed 77

Third cousins 13

Third cousins once removed 90

Fourth cousins 73

Fourth cousins once removed 89

Fifth cousins 17

Fifth cousins once removed 31

Page 54: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

MyFTDNA dashboard

Page 55: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

AtDNA Ethnic Origins

Page 56: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Autosomal DNA matches

Page 57: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Chromosome Browser

Page 58: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

Chromosome mappingSome people take this even further and map their chromosome by comparison with lots of different relatives!

Page 59: Genealogical DNA Tests and Links · 2017. 11. 30. · Genealogical DNA Testing Agenealogical DNA test is aDNA-basedtest which looks at specific locations of a person's genome in order

References/Sources

● International Society of Genetic Genealogy https://isogg.org/

● Wheaton Surname Resources – Beginners Guide to Genetic Genealogyhttps://sites.google.com/site/wheatonsurname/home

● Kitty Cooper’s Blog http://blog.kittycooper.com/● Debbie Kennett - DNA and Social Networking: A

Guide to Genealogy in the Twenty-First Century (Warrington Library)