Genetics & Genealogy - An Introduction

Genetics & Genealogy - An Introduction

With Some DNA Case Study Examples

This report was first prepared as a handout for a lecture presented by me

at a Genealogical Conference in Reading, PA, in October 2001.

I have updated it and added to it along the way adding more graphics, etc.

Last Revision or Edit: 23 February 2013

Notice: Establishing or posting links to this report/website material is encouraged and permitted. But, reuse or reprinting it in its entirety or in part in other websites, email, or mail lists, or in any other media or publication, without my expressed permission, is not permitted. Printing a single hard copy of this report for your own personal, non-commercial use is permitted.

What Is DNA?

DNA is short for DeoxyriboNucleic Acid. DNA is a double-stranded helical molecule found in the cells of all organisms. DNA contains the biological, genetic instructions to build an organism. DNA also controls the day-to-day function of all cells. These instructions are passed down from parent to child via the DNA we inherit from our parents. A gene is an instruction containing section of the long, double-stranded helical molecule of DNA which contains specific instructions for some specific function such as making a protein. About 25 thousand genes are packaged in the DNA packages called chromosomes. 46 chromosomes arranged in 23 pairs or sets define the human genome. The complete human genome contains billions of bits of information.

As just explained, the DNA in the nucleus of our cells contains 2 sets or pairs of chromosomes. Each parent provides one set. Each set has 23 single chromosomes; 22 autosomes and an X or Y gender chromosome. Basic biology and genetics tells us that the 23rd chromosome pair is the chromosome set that determines gender. Males have both an "X" and a "Y" in their 23rd chromosome pair and are thus “XY”, but females carry two X’s or an "XX" for their 23rd chromosome pair. The unfertilized human egg cell always has a single X chromosome obtained randomly from one of the mother’s two X chromosomes when the egg cell is produced. The human egg will become a female embryo if the male sperm that initially reaches the egg cell carries an X-chromosome. The egg will become a male embryo if the male sperm that initially reaches the egg cell carries a Y-chromosome. The male embryo thus gets its Y chromosome from the father who in turn got it from his father. Thus you can see the Y-chromosome is passed down from generation to generation only through the male line. In order to better understand how we arrived at this point, we need to reach for the next level.

The complete set of DNA instructions for making an organism is called its genome. Found in the nucleus of a person’s many cells, the human genome consists of tightly coiled threads of deoxyribonucleic acid (DNA) and associated protein molecules, organized into structures called chromosomes. In humans, as in other higher organisms, a DNA molecule consists of two strands that wrap around each other to resemble a twisted ladder whose sides, made of sugar and phosphate molecules are connected by rungs of nitrogen--containing chemicals called bases. Each strand is a linear arrangement of repeating similar units called nucleotides, which are each composed of one sugar, one phosphate, and a nitrogenous base. Four different bases are present in DNA: adenine (A), thymine (T), guanine (G), and cytosine (C). See Fig. 1 on next page. The particular order of the letter bases arranged along the sugar-phosphate backbone of the DNA double helix ladder shaped molecule is called the DNA sequence. Specific sequences of three letter bases make a DNA “word” which codes for an amino acid. A string of DNA “words” strung together in a sequence form a “DNA sentence”, aka a gene, which contains the instructions to make a particular protein. Protein is used to build the organism. Many “sentences”, aka many genes and we have the instructions to make the entire organism. These sequences specify the exact genetic instructions required to create a particular organism with its own unique traits.

The two DNA strands are held together by weak bonds between the bases on each strand, forming base pairs (bp). The human genome contains over 3 billion base pairs (bp). The complete detailed and verified mapping of the entire human genome was completed in 2003.

As we just learned, the three billion base pairs (bp) in the human genome are organized into 23 distinct, physically separate microscopic units or packets called chromosomes. All genes are arranged linearly along the chromosomes. Genes are like island of information in the overall DNA molecule sequence. In between are vast sequences which do not code for proteins and have no known function for the organism. Those vast areas in between the genes are referred to as junk DNA by geneticists. But as we shall see later one man’s junk is another man’s treasure. It is in these junk DNA areas that we find the STR markers used in Genetic Genealogy tests to determine relationships. The focus of this lecture is to learn how to use certain specific types of DNA information, which is passed down from parent to child over generations, to aide in solving genealogical puzzles.

Figure 1 - Pictorial Example of Nuclear DNA Structure

Credit: Original source image which I reworked was from University of California, Lawrence Livermore National Laboratory, and the Department of Energy.

(Note: The above image has been re-worked by me. It has twist correction, fixes, and other edits by me for use in this report.)

Types of DNA

Autosomal DNA (atDNA) – Nuclear DNA information which makes up our individual genetic identity which is the random combination of all genetic information passed down to us from all our blood-line ancestors and is contained in the nuclear DNA consisting of the merged set of chromosomes found in the nucleus of cells. These are the chromosomes that determine our unique identity and appearance. We get this randomly assorted merged set of chromosomes from our mother and father. There are 44 autosomal chromosomes arranged in 22 pairs numbered 1-22 from the largest set to the smallest set. Autosomal atDNA STR markers are what are used for the typical paternity tests and individual identity tests in forensic tests.

Y chromosome DNA (Y-DNA) - Nuclear DNA information which is found in the Y chromosome which only exists in males. One of two gender determining chromosomes. The Y chromosome is passed along from male to male via a sperm cell which contained the Y chromosome of the father. The sperm cell having a Y chromosome determines that the child will be male. Thus only males have the Y chromosome and only males can pass along the Y chromosome from father to sons. Y-DNA STR markers are what are used in typical surname projects.

X chromosome DNA (X-DNA) - Nuclear DNA information which is found in the X chromosome which exists in males and females. One of two gender determining chromosomes. Males have one X chromosome and a Y chromosome and females have two X chromosomes. X chromosomes when paired in females interchange genetic information via cross-over effects similar to what happens with the autosomal chromosomes. Thus after a very few generation it is very difficult to track the ancestry of a particular X chromosome X-DNA genetic marker pattern. However, the X chromosome is used sometimes in specialized tests in some family reconstruction analysis cases.

Mitochondrial DNA (mtDNA) - Non-nuclear DNA which is a small DNA molecule contained in the Mitochondria organelles which are located inside the cells of all of a mother’s children, both male and female. The Mitochondria organelles are not in the nucleus of the cell but are outside the nucleus. Thus mtDNA is not nuclear DNA and is found inside the Mitochondria organelles located inside the cell but outside the nucleus of the cell. We get our Mitochondria only via the egg cell of our mother. Therefore only females can pass on mtDNA to their offspring.

Figure 2 - Rudimentary Pictorial of DNA Containing Organelles in a Human Cell

Credit: FamilyTreeDNA.com

Types of DNA of Most Interest to Genealogists?

A) Y Chromosome (Nuclear) or Y-DNA

All men and only men have a Y chromosome. This biological fact allows us to trace back in time a direct, largely unchanged genetic line of inheritance from father to son.

Every person, male or female has 22 matching pairs of chromosome -- one inherited from each parent -- but the 23rd pair is different. This unmatched pair, known as the X and Y gender chromosomes, determines whether we are male (XY) or female (XX). A mother always provides a single X chromosome in her egg. Inherit an X from your father and you will be a female, receive a copy of his Y and you will be male. And so the Y chromosome travels from father to son with each successive generation of males.

The second thing that makes the Y chromosome unique is that the information carried on Y-chromosomes is inherited largely intact over time. Unlike other chromosomes, the genetic material on the Y chromosome is not mixed with each new generation. The reason is that when cells divide in preparation to make sperm and egg, all 23-chromosome pairs line up to exchange random bits and pieces of DNA with their matching partner before separating. All the chromosomes do this exchange of genetic material save the mismatched XY pair. The Y is much shorter and very little of its genetic information is broken up in an exchange of DNA with the X chromosome. The information carried on the Y chromosome travels from father to son as a nearly exact copy of itself.

Occasionally, during the DNA copying process small changes or mutations occur, and it is these mutational differences that allow us to distinguish the Y chromosome of an individual from his ancestor's. Thus an actual genetic record of the male line going back through time exists -- as clear a marker of paternal heritage as a father's family name.

A tangible timekeeper of history, the Y chromosome allows us to trace human evolution, track migration patterns and relatedness in groups of people, and answer paternity questions going back generations. As we pull apart the Y chromosome, we begin to unravel some fascinating stories about our own origins. Population geneticists and anthropologists have categorized human Y-DNA into about two dozen distinct major groups called Haplogroups, with many sub groups assigned to each group.

B) Mitochondria or mtDNA

Mitochondria--The energy component in all cells in the human body is passed from mothers to all their children through the union of the mother’s egg and the male’s sperm. Mitochondria organelles are located outside of the cell’s nucleus and have their own DNA. The mtDNA molecule is much shorter than the nuclear DNA. It is only about 16,500 base pair in length and it is arranged in a small circle like a donut. Compare that to nuclear DNA which is about 3.2 billion base pair in length and is arranged in a long spiraled and coiled thread like structure. The typically basic mtDNA test yields a standardized result of 400 base pairs that are compared to the Cambridge Reference Sequence (CRS). The results of the test, which will include the Hyper Variable Section #1 of the control area of the mtDNA, will yield a few base pairs that differ from the standard Cambridge Reference Sequence (CRS). Since the standard was created around a western European woman, the more changes one has from the standard the farther back in time one’s mtDNA would have split from the base of the genetic tree. For example most Africans have 7 or 9 differences while most Europeans have a few or perhaps 5 of these polymorphism from the Cambridge Reference Sequence (CRS). One’s maternal ancient Haplogroup is determined from the basic mtDNA test. Advanced, refined, or so called mtDNA Plus tests also test a second region of the mtDNA called Hyper Variable Section #2. The additional data from the second Section when combined with the first section results allows greater differentiation between individual’s maternal line and reduces the time to your most recent common maternal ancestor when you have an exact match between two people for both HVS1 and HVS2.

Population geneticists and anthropologists have categorized human mtDNA into about 30 distinct major groups called Haplogroups, with many sub groups assigned to each group.

If you match someone on the mtDNA side you will know that you and they share a common female ancestor, but the time to the MRCA is typically several thousand years ago, and certainly not less then many hundreds of years group. FTDNA, the company I use for testing, also offers an refined/enhanced mtDNA Plus test that examines the HVS2 section of the Mitochondria to reduce the time predictions to the Most Recent Common Ancestor (MRCA) in the female direct line.

Figure 3 - Y-DNA Paternal Line and mtDNA Maternal Line Inheritance Charts

Shows How the Y-Chromosome (Y-DNA) and Mitochondria (mtDNA) Are Inherited

How Can DNA Analysis Help Genealogists?

Genetic comparisons can determine if a person is or is not genetically closely related to another person. But we should be aware that there are limitations using current Y-DNA or mtDNA testing. One can determine that two people are related but one cannot determine the degree of the blood relationship. In addition to the typical paternity tests that most people are familiar with for use with the most recent generation, these are some of the basic DNA tests that are available and useful to the family genealogist for investigating genealogical relationships in earlier generations on the Pedigree Chart - .

The Y-Chromosome YSTR DNA Test (Y-DNA)

The Y-chromosome, in the nuclear DNA of every living male, is virtually identical to that of his father, his paternal grandfather, etc., and is carried by male cousins of any degree of relationship that share the same male ancestor. It provides a clear set of YSTR genetic marker results expressed as a set of numbers, known as a haplotype, which distinguishes one male-to-male lineage from another. See this website for an example of using Y-DNA for genealogy: “http://www.kerchner.com/kerchdna.htm” or “http://www.kerchner.com/success.htm”.

The Y-chromosome Test Can Help Determine:

1. Whether two or more specific individual men share a common male ancestor and did that ancestor live in a time frame of genealogical interest, i.e., the advent surnames.

2. If a set of two or more men with the same or similar sounding or meaning surname are directly related through a common male ancestor.

3. How many different common male ancestors any given group shares.

4. Unrelated same name clans so you do not waste time trying to find a connection to same named lines you are not related to, i.e., sorting out which Millers or Smiths are yours.

4. To which broad pre-history, deep ancestry haplogroup each individual male’s Y chromosome haplotype belongs.

5. An analysis of the mutations in the Y-chromosome can also be used to estimate the degree of separation between individual males in terms of number of generations since the separation occurred. Most Recent Common Ancestor (MRCA) is another way of expressing this separation. There is currently a debate over the 'natural' rate of mutation over time. A mutation can occur at any time. Natural mutations have been postulated to be occurring on average about once per 500 generations per marker. But some family surname Y-DNA studies are observing average mutation rates of about twice that rate, i.e., once per 250 generations per marker. See this website for more information on YDNA YSTR mutation rates: “http://www.kerchner.com/dnamutationrates.htm”. Also it is now acknowledged that some Y-DNA DYS markers mutate at a higher average rate than other Y-DNA DYS markers.

The Mitochondria DNA Test (mtDNA)

The mtDNA test looks at the DNA of the mitochondria, a special part of all-human cells, which is passed on, female-to-child, and inherited down the female line. It is generally used to study long-term population developments such as human migrations. It is a favorite genetic tool of Anthropologists. Your Mitochondria DNA sequence test is compared to a standard reference called the Cambridge Reference Sequence (CRS). The Mitochondria DNA (mtDNA) test can reveal detail about the distant origins and deep ancestry haplogroup of your direct line maternal ancestors and could be used to link individuals via the female line. The mtDNA test will also determine your maternal Haplogroup and the area of the world where that direct female ancestor is thought to have lived. However, for genealogical purposes, even if you are tested with the enhanced/refined or so-called mtDNA Plus test, it not as precise in resolution of time to Most Recent Common Ancestor as the male Y-DNA test, and since the female line birth/maiden names quickly get lost in history, the mtDNA test is thus generally not as useful for genealogical purposes as the Y-DNA test. But it can be used to confirm scientifically that two people share a common female direct maternal line ancestor if one is suspected via traditional genealogical research. MtDNA has been extensively studied for over 20 years and is used quite extensively for anthropological studies. Interesting migration maps have been created to show the spread of different female lines throughout the world. A new mtDNA is now available which sequences the whole mtDNA molelcule. This test is called the Full Sequence Test (FST) and is also known as the Full Genome Sequence (FGS) test. Since the FST sequences the whole mtDNA molecule anyone thinking of doing this new FST test should understand that not only will it reveal your genetic genealogy markers but it also will potentially reveal medically relevant information in the gene regions of the mtDNA molecule. Thus you should consult carefully with the testing company to be sure that is what you want before ordering a mtDNA Full Sequence Test.

The SNP (Single Nucleotide Polymorphism) or ‘snip’ Test

A deep and ancient ancestry haplogroup affiliation determination and confirmation DNA test. It tests for known variations in the nucleotide allele at an exact specified nucleotide position in the human DNA genome. These single letter changes in our DNA sequence occurred over time many thousands of years ago and are indicative of the major groups of human populations called haplogroups. These singular nucleotide allele variations in the human genome DNA sequence (a base A becomes the base T, a base A becomes a G, or other similar variations) occur at a frequency of about one in every 1,000 bases in the genome. When a change, i.e., mutation is observed at a nucleotide position it is called a polymorphism, which literally means many forms. But in the case of the nucleotides looked at with SNP tests there are usually only two forms, the original base letter and the more recent mutated base letter such as the A at that location becomes a T. These single nucleotide variations are used to determine very deep ancestry inheritance in groups and clades of people over long periods of time and the evolution of the human genome over time. SNP is pronounced "snip". SNPs are used to plot the phylogenetic tree which shows the relationship of all current human haplogroups to the original ancestor who walked out of Africa. For a Y chromosome phylogenetic tree examples see: “http://www.familytreedna.com/haplotree.html” and “http://www.isogg.org/tree/index.html”.

The BioGeographical Ancestry (BGA) DNA Test (atDNA)

The BioGeographical (BGA) Ancestry Test marketed under the trade name of DNAPrint is the latest DNA test available for the use of the genealogist. It examines Ancestry Informative Markers (AIMs) found in the autosomal chromosome pairs (atDNA) inherited from the father and mother, who in turn got them from their mothers and fathers, and so on back into time. Certain marker allele values occur at higher frequency in one population group as compared to another population group. By determining which AIM allele value results one has at about 71 marker locations in one’s autosomal chromosomes and then running those marker data results through DNAPrint’s proprietary computer algorithm, DNAPrint provides you with a report of your population group genetic mixture expressed as percentages divided by this company into 4 major population groups identified by DNAPrint: Indo-European, East Asian, Native American, and Sub-Saharan African. The sum of these four percentage allocations to each population group of course must add up to 100%. One could test out as 100,0,0,0 or 0,0,0,100, or 79,21,0,0, or 80,10,5,5, etc. One could be found to be genetically placed all in one group, or alternatively mostly in one group and with some minority percentage of one or more of the other groups, or with some content from all four groups. Which ever group result shows more than 50% content is called the dominant population group. While the test claims it can allocate your genetic material origin to various population groups, the test cannot differentiate between whether the markers are from recent (in a genealogical time frame) or from ancient times. Thus the BGA test results cannot be used in a vacuum and must be used in conjunction with other genealogical evidence when used for genealogical purposes. For example, a genealogist could use this test to help prove or disprove a rumor or family legend which is alleged to have occurred in your genealogically recent family tree that a grandparent, great-grandparent, or gg-grandparent was of a different population group then the dominant population group of one’s family tree. This BGA test can also be used to detect minority admixture markers in one’s genome derived from ancient sources, and thus also can be used for anthropological projects. See this website for an example of using the BGA test: “http://www.kerchner.com/pa-gerdna.htm”. A more recent addition to the testing of atDNA is the Family Finder test offered by FamilyTreeDNA.com. This test reports the percentage admixture from various populations in the Population Finder portion of its results. But it also finds closer atDNA matches to others who have taken the Family Finder test and who share a substantial amount of atDNA and are thus recently closely related … anywhere from parent to child, siblings, first cousins and on back to 5^th cousins, etc. The Family Finder test is relatively new and is finding many new and useful uses by genetic genealogists.

What Does DNA Test Kit and Test Results Look Like? Prices?

The typical DNA specimen collection test kit comes in a small envelope and usually consists of two swabs which look like tooth brushes. No needles or blood samples are used. Detailed instructions for the use of the swabs is included but basically these sterile swabs are used to swab the inner lining of your cheeks for about 30 seconds to gather cells for DNA testing. It is simple and totally painless. There are also vials containing a preservative liquid in which the swab heads are inserted for return to the test lab. If you are sharing your test results with a database or family project there will also be a simple release form which you must sign to allow the lab to share your results with the database or the family project coordinator.

The Y chromosome Y-DNA test results are a series of numbers which are used to compare your results to others. This is usually a series of 12, 25, 37, 43, or 67 numbers. For the 37 marker Y-DNA test, if the series of 37 numbers for two men being tested is exactly the same, or if only 1 or at most four markers are off by a count of 1 step, and you share the same or a similar surname, then you each are probably closely genetically related in a time frame of genealogical interest, i.e., the last 500 years, and have a recent common male ancestor. If you match exactly 37/37 and share the same or similar sound or meaning surname you probably share a common ancestor within the last 5 generations. The more mismatches the further back in time the common ancestor is likely to be. To get the best estimate as to the time frame the shared common ancestor lived test as many markers as you can afford. I recommend at a minimum of 37. Here is why: “http://www.kerchner.com/zip+4-analogy.htm”.

Prices run about $259 for a Y-DNA 37 marker analysis. Group discounts for surname study projects are available from most test labs. Prices are dropping every year as more and more people are being tested and economies of scale are being introduced by the testing labs.

Figure 4 - Picture of DNA Specimen Collection Kit

Credits: Picture Courtesy of FamilyTreeDNA.com

Figure 5 – Typical 37 Marker Y-DNA Test Results Certificate

What Are The Rewards And Risks of DNA Testing?

The rewards from DNA testing are obvious for the genealogist…those being, to either confirm or rebuke the theory that two people are related through a common ancestor. The value in this is immense…given the amount of time and expense that most genealogical enthusiasts spend on this consuming hobby. Why travel to Germany or England to search for records of people who might be related to you when you can insure that each hour spent will be invested on record collecting for absolute members of your extended family.

While the rewards can be great, i.e., confirming that needle in the haystack, the risks can be daunting as well. In practically every family reconstruction project an example of a ‘surprise negative’ becomes visible. These unexpected events arise when two known relatives show up as not matching, and I’m not talking about being off by 1 or 2 data point steps, but by many data point steps on many markers when comparing haplotypes even to the point of being in different deep ancestry haplogroups, i.e., no likelihood of a common ancestor for thousands of years back in time. Some reasons for these sometimes embarrassing surprises are:

A. Prior research error. The prior historical genealogical research of earlier family members, county histories, or lineage societies, etc., is simply wrong.

B. Unannounced and hidden adoptions. Many times in the past a calamity would take place and a neighboring youth would be raised by a family. Or maybe some couple was childless and someone arranged an “adoption” but no one was told about it nor was it written down. Thus the child was given the surname of the ‘adopted’ family as he/she was raised as one of their own.

C. False Paternity Event aka Non-paternity Event. The biological father was different from the historically known father and/or legally recorded father and no one until now knew or if they knew they were not talking about it.

D. Family name change. An ancestor decided to change their name and adopt the surname of another family in their original area of residence and then moved away. This could have been done because they didn’t like their real surname or maybe because they liked the other surname and decided to use that name to start a new life. This is sometimes seen in history with people adopting the names of famous or rich deceased people and then pretending to be a descendant and heir to that family line.

The incidence of some of these situations over the generations is estimated to average between 2-5% PER GENERATION by population geneticists. When results come back and a surprise negative is found it can be a very delicate situation for a family to deal with. If a re-construction project is underway within the family, after a re-test of the individual(s) is completed to double confirm the surprise negative, this is the time for the “Family Coordinator” to sit down and have a polite but open, frank discussion with the person who is surprised by the results and talk about how they would like these facts treated. Every situation is different and different people will react to such information in very different ways. Therefore, great care must be taken in presenting such information when doing a family re-construction project.

Case Studies

Kerchner—An evolving project which used DNA testing to establish a Y-DNA haplotype profile for the male descendants of the immigrant Adam Kerchner, who arrived in PA in 1741 on the ship Thane of Fife and then compare those results with the haplotypes of other Kerchner lines to see if they are related. This initial step took courage since there is always the possibility of surprise results. But it turned out well. The 5^th and 2^nd cousin tests positively confirmed the historical genealogical records and research for this clan of Kerchners and known descendants. Once a proven ancestral haplotype profile was established for Adam Kerchner’s clan, this ancestral haplotype could then be used as a reference to see if Adam Kerchner’s descendants were biologically related to other male Kerchner clan descendants such as the male descendants of the immigrant Frederick Kerchner, who arrived in PA in 1751 on the ship Brothers. Some researchers have theorized they were related. Both immigrants settled in the same geographic area, Hereford Township and Longswamp Township area of Berks Co PA, and the early family and historical records of the two families are often confused. The immigrant Frederick Kerchner and his family moved from the Berks County PA area to the Bedford County PA area in the late 1700’s. While there is no known historical, legal or church inter-relationship between the families, the two families used similar given names and it was thought by many researchers that the two immigrants could be closely related, possibly cousins or maybe even brothers. Initial Y-DNA testing of one recorded descendant of the 1751 immigrant Frederick Kerchner was done. The very early, initial results did not completely confirm or disprove the theory. Since only 12 markers were used and we did not get an exact match at that resolution, we could not say for sure he was closely related or that he was not closely related. In the absence of an exact match, or a large mismatch, a 12 marker test is just not clear enough. Thus the initial tests did not conclusively prove or disprove that he was recently related to the 1741 immigrant Adam Kerchner. The 12 marker haplotype of the descendant tested of the immigrant Frederick Kerchner were off by two steps from the Adam Kerchner 12 marker haplotype which is more than would be expected if he was very closely and recently related to Adam Kerchner’s line, such as being a brother of Adam when they both arrived in PA. A 12 for 12 match is what is desired or at most a one step variance. However, additional testing of more markers over the next year using newer refined tests plus using a second laboratory yielded a match of 33 markers out of 35 tested. Thus the relationship grew statistically very close indeed. This indicated that Frederick and Adam were indeed related, but probably not brothers. They were most likely first to fourth cousins of each other. See the websites http://www.kerchner.com/kerchdna.htm, http://www.kerchner.com/success.htm, and http://www.kerchner.com/labmerge.htm as well as the Kerchner Surname Project handout for more details about the results and the continuing plans for this Y-DNA surname project.

Thomas Jefferson-Hemings—Used Y-DNA analysis to prove that Thomas Jefferson, or a Jefferson family male blood relative such as an uncle or nephew, fathered children with a slave named Sally Hemings who worked inside the home of Thomas Jefferson. Hand me down stories of the descendants of the slave Sally Hemings stated that Thomas Jefferson was their ancestor. Circumstantial evidence indicated that Thomas Jefferson’s and Sally Hemings had the opportunity for an intimate relationship since she lived in the home of Thomas Jefferson and she traveled and lived with him in Europe during diplomatic visits. Now the new Y-DNA tests confirm the merits of the Sally Hemings descendants’ family oral history and other historical evidence. For more information see the Associated Press story by Malcolm Ritter printed in the Sunday, 1 November 1998 issue of the Morning Call newspaper. Many more details about this Thomas Jefferson DNA project can be found on the Internet using search engines such as Google.com by searching under the key words “Thomas Jefferson DNA Project”. Here is the address for a website I found particularly succinct in describing the Jefferson-Hemings history and Y-DNA analysis and results: “http://www.monticello.org/plantation/hemingscontro/dnareport4.html”.

Mumma—Used Y-DNA testing to prove that the American Mummas were related to the German Mummahs and then further confirmed that a Swedish family, named Reenstjerna was, in fact related to the German Mummah clan. Family lore had it that the Reenstjerna Clan has been Mummahs and had immigrated to Sweden several hundred years ago; in fact the common ancestor between the Reenstjerna and Mummah families was born in the year of 1541. See website: http://www.mumma.org/DNA.htm for more details. Note: The letters DNA in the website address must be capitalized as shown in the address.

Duerinck—Used Y-DNA testing to prove that the American Duerinck’s were related to the Belgium Dierick’s. The Duerinck website also has lots of excellent information on using Y-DNA testing and interpreting the results. See website: http://www.duerinck.com/results.html for more details.

Melungeon—Current studies are underway to attempt to decipher the exact background of the Melungeon, a group of people that are alleged to have inhabited the Tennessee Valley of the Appalachian Mountains for about 400 years. Their exact background and origin is not known with certainty. Also who are and are not Melungeon descendants is not known with certainty. It is reported by some that the people who became known as the Melungeon came to the New World from somewhere in the Mediterranean or Europe before the English settlements in Virginia. Some researchers also state that early English explorers discovered them living in the Tennessee Valley of the Appalachian Mountains around 1654. See website: http://homepages.rootsweb.com/~mtnties/definition.html for more details.

Sorenson Foundation Molecular Genealogy Research Project (MGRP)—The goal of the MGRP is to build a database of genetic markers that will, in the future, be used to answer genealogical questions that cannot be answered using normal genealogical research methods. The Project plans to collect 100,000 samples from people around the world. The samples will be analyzed and the results will be related to the four-generation pedigree chart submitted with each sample. These 100,000 individual samples will be organized into approximately 500 population subgroups. At some time, several years, in the future a person will be able to submit a DNA sample for analysis and comparison to this large database to determine the probable geographic location of your genetic ancestry based on the similarities in your genetic markers when compared to the genetic markers of the 500 population subgroups. See website: http://smgf.org/ for more details.

PA Deutsch Ethnic Group DNA Project—Hypothesis: That a significant percentage of people, or sub-groups, within the Pennsylvania Deutsch/German (aka PA Dutch) ethnic group may have a significant average percentage, but not dominant percentage, of Asian genetic content in their genome, of non-recent origin in a genealogist's time frame, possibly harbored in their genome from the major invasions of southern Germany by tribes from Asia such as the Huns and Mongol hordes which invaded Europe at various times during the period of 1600-700 years ago, or of even older more ancient origin. Data collected by this project, and subsequent analysis, will attempt to prove or disprove this hypothesis and/or will be used to try and get an anthropologist or population geneticist to look at this possible "discovery" about the PA Deutsch in greater detail. See the webpage for more details: “http://www.kerchner.com/pa-gerdna.htm”.

Frequently Asked Questions

Note: I have chosen FamilyTreeDNA.com as the testing service company for my Kerchner

Y-DNA Project however similar procedures and results can be achieved with other companies.

Here are some FAQ questions and answers they provided me to share with you.

When should I use genetic testing services?

When you want prove or disprove a surmised genealogical relationship which you are unable to resolve with existing historical and genealogical evidence. You may also decide to use genetic testing to scientifically confirm the known genealogical relationship between distant cousin branches as a further proof of the relationship and the validity of your research. You may also wish to contribute your DNA sample to the various DNA database libraries to build the library of known DNA marker profiles to potentially help others and using the principle of serendipity that someone, someday, somewhere will match your profile and you will find new previously unknown cousins. Used in conjunction with existing genealogical records, DNA testing helps you break down brick walls and fill in the gaps in proving or disproving assertions where little or no written historical records or other traditional genealogical evidence exists to support the assertions. As an example, DNA testing can determine and prove descent from your father's father’s father or your mother's mother’s mother. That means in the case of an individual's great-grandparent's generation, we can determine and prove a link to two of your eight great-grandparents, and so on back into time along the direct male and direct female lines. You can, however, also determine some other type family links by obtaining DNA samples from your male and female cousins. Contact www.FamilyTreeDNA.com for more details on exactly what genealogical information can and cannot be determined by testing samples from various individuals in your tree.

What steps does Family Tree DNA take to keep my results confidential?

Your privacy is assured because the testing facility will not have access to your name. Only your unique Kit ID number will accompany your collection tube to the testing lab. The computer-generated number is the only information about you that the testing facility will see. Once your test has been completed, the results will be entered in a secure non-web-based database, and the lab will inform us of any matches between two coded numbers. The information placed in FTDNA’s Surnames Database Library will only display your last name on their web site. However, if you authorize it and sign the release form, you can have your contact name and email address displayed for those who exactly or closely match your test results so they can contact you. No other specific information about you will be available at the web site.

Suppose I have a distant cousin in another country and we both send our specimens separately, how will you know that we want to confirm our family connections?

Unless you ordered together or sent in your samples together the testing company wouldn't know that you wanted to share results with each other. However sharing results is not a problem if you sign the simple release form included with every test kit. When the release form is signed FTDNA can then automatically release specific contact information to you and other people who have an exact match to you. If you are specifically testing with another individual, just send FamilyTreeDNA.com an email after you place your order notifying them of that fact.

I am researching a family with many distinct branches. How many people from each branch should I use?

This is an important and very practical question that speaks to the heart of genealogical testing and research. The chance that a match does not exist due to infidelity or unreported adoptions occurs 2%-5% of the time per generation. For families trying to do family reconstruction, it is prudent to test at least 2 different known male cousins from each different branch. In cases of unexpected results, FTDNA will retest you at no charge to confirm that a lab error is not an issue.

Does the genetic marker analysis shows that I may carry a problematic gene, and if so, will I be informed?

No your genealogical DNA test would not show that information and thus you could not be informed since medically related information is not revealed by genealogical DNA testing. The testing lab would not know you show positive for a genetic disease, as the lab is only testing your DNA and looking at 12/25/37 specific loci on the Y Chromosome, or in the case of the mtDNA, the markers associated with that test, which are located at different positions on your DNA molecule than where the genes for known gene related diseases are located. Genetic Genealogy DNA markers are located in the vast areas of “junk DNA” in between the genes.

Will I have the right to remove my genetic profile from the database at some later time?

Yes. Similar to an email list, if you decide that you want your data deleted from the database, you email FamilyTreeDNA.com, they will look up you ID number, and delete it from the Database. It is a good idea to write down where you can find it, the ID number and sample code of your test kit for convenient future reference.

How is the test performed?

You do the test yourself in your home. No blood is used. Your genetic test kit consists of two cheek scrapers and collection tubes. In about five minutes, you will be able to read the instructions and perform the painless inner cheek scraping. The effect of using the scraper is about the same as brushing your cheek with a soft bristle toothbrush. The second scraper and tube is included so you may take two samples to insure that a good sample is obtained by our lab. You should always use both scrapers and submit the two samples. You also need to sign the simple release form enclosed with the kit if you wish to share your results with their database and/or a surname project coordinator.

How much do these tests offered by Family Tree DNA cost?

The newest “Paternal Line 37 Marker Match” (using Y-DNA) is priced at $259. And the lower cost basic “Paternal line 12 Marker Match” is priced at $149. The high precision 67 marker test is $349. At a minimum the 37 marker test is recommended since it provides more information and precision when comparing individual’s results for genealogical uses. The basic "Maternal Line Match" (using mtDNA) is priced at $129 each. An enhanced maternal line mtDNA Plus test is available for $189. Also offered is a combined 37 Marker Y-DNA and mtDNA Plus test which combines both tests above (for males who want to test both their father’s, father’s, father’s Y-DNA lineage and their mother's, mother’s, mother’s mtDNA lineage). The combined test is $389 and is worth considering if funds are available and you want to learn what you can about your direct paternal and direct maternal lines.

FTDNA’s also has specialized tests for Native Americans, and are available for either the female or male side. They are designed to tell you from which immigration to the new world your male or female Native American family progenitor arrived. To successfully take this test your lines of descent must be female to female to female (or male to male to male) all the way back to the person who was known to be 100% of Native Ancestry. Contact FamilyTreeDNA.com for prices on the Native American tests.

Also offered is the world’s only "Cohanim" test for males of Jewish lineage. Contact FamilyTreeDNA.com for prices on the Cohanim tests for Jewish lineage.

Here is the link to the FTDNA website for more information: “http://www.familytreedna.com/cj.asp?ftdna_ref=114”.