Congratulations on completing your BioGeographical Ancestry Test!
At CRI Genetics, we hope to have helped you achieve your goals in learning more about yourself and your family history.
In this manual, we aim to help you understand the results you received and answer any questions you may have about your reports and about DNA testing in general.
The documents you have received are products of extensive scientific research from a combination of Geneticists, Anthropologists, and Social Scientists. We hold ourselves to the highest of standards and have made it a priority to ensure that our methods of testing and analysis are scientifically, statistically, and historically sound. With our patented advanced software, your DNA has been compared to thousands of samples from populations all around the globe with a focus on select DNA markers that can point to clues about your unique ancestry.
First, we’ll give you some basic information about human evolution, history, and DNA. Then, we’ll discuss our ancestry testing services and show you some resources if you want to learn even more on your own.
Scientists around the globe learn more and more about ancestral genetics and worldwide human migration every day. Now you, too, can join in the voyage of understanding who we are and where we came from. Your test results will give you a glimpse into your unique place in our ancestral history.
our BioGeographical Ancestry Report contains a certificate with a percentage breakdown of your Ancestry and a bar graph that shows how confident we are in those percentages (which we’ll explain more later in this manual).
Here, we’ll go over some basic information about biology and the inheritance of DNA. As you probably know, DNA is a material found in ALL living things, a sort of genetic blueprint. Each cell in every living organism contains a full copy of that organism’s DNA, which encodes ALL of how the body is put together and the functions of every part.
You’ve most likely seen DNA depicted as a “double helix,” which sort of looks like a twisted ladder or a spiral staircase. If every helix in just one of your body’s cells were to be stretched out and placed end to end, you could create a ladder that’s about 3 meters (or almost 10 ft) long. However, in your body’s cells, these helixes are actually tightly coiled together in packages called Chromosomes.
If we continue to think of the helixes as ladders, the “rungs” are hydrogen bonds that pair together molecules of four bases: Adenine (A), Thymine (T), Guanine (G), and Cytosine (C).
The way that these molecules are arranged is called the “DNA sequence,” which is the “blueprint” we mentioned before. This instructions on this “blueprint” are found in Genes, which map out your physical characteristics and body functions.
However, not ALL of your DNA sequences code for your genes—the majority of your DNA is actually found in non-coding regions. The DNA in these non-coding regions serves a wide range of other purposes. Many of these non-coding regions happen to have markers that are useful for human identification and ancestry studies.
At CRI Genetics, we want your experience to be as informative as possible, while also being as understandable as possible. So, we’ve compiled a list of scientific terms you might come across while you browse this manual and your reports.
There are three types of DNA we use to trace your Ancestry:
1) Y-Chromosome (Y-DNA) – You inherited 23 Chromosomes from your father, one of which was either an X or a Y. If you’re a woman, you inherited an X, which means you don’t have a Y-Chromosome. If you’re a man, you inherited a Y—that specific chromosome remains mostly unchanged through generations of inheritance, so we use that to trace direct Paternal Lineage.
2) Mitochondrial DNA (mtDNA) – As you know, you inherit 46 Chromosomes from your parents—23 from your mother, 23 from your father. All 46 Chromosomes are found inside the nuclei of your body’s cells. Your Mitochondrial DNA (mtDNA) exists OUTSIDE of the cell nucleus. Whether you are male or female, ALL of your mtDNA is inherited from your mother, as it comes from the egg at fertilization. This direct maternal inheritance allows us to trace direct Maternal Lineage.
3) Autosomes – Your 44 non-sex chromosomes that make up the rest of your genome. Our BioGeographical Ancestry Test examines 176 markers across these Autosomes, which we call Ancestry Informative Markers (AIMs).
The illustration above demonstrates the difference between the 3 types of inherited DNA. You are the figure at the bottom of the diagram, your parents are above you, your grandparents are above them, etc. The figures in light green represent your direct Paternal and Maternal Lineage, which gets traced via the Y-DNA and mtDNA Tests. The Autosomal DNA Test for your BioGeographical Ancestry Report provides information about the total genetic contribution of ALL your ancestors (both light and dark green), but does not trace direct lineage.
Your 22 Autosome pairs are particularly useful for estimating a breakdown of your BioGeographical Ancestry as they are mixed together so that your genome contains segments of DNA from ALL of your ancestors.
It’s important to note that not all Ancestry is passed down equally. For example, let’s say you have a mother who is half European, half Asian. Let’s say your father is half African, half Native American. Your Ancestry not be split 25-25-25-25 between those 4 major regions like you might expect.
As you certainly know by now, you inherit a total of 46 chromosomes from your parents (23 from each parent). Your parents inherited a total of 46 from THEIR parents (23 from each of your grandparents). So, using the same example: of your mother’s 46 total chromosomes, you only got 23 of them. You could conceivably inherit 17 of her European chromosomes and only 6 of her African chromosomes (though your inheritance is also not likely to be quite that one-sided).
Of any 1 chromosome you inherit from your mother, it could be from either your maternal grandmother OR your maternal grandfather. You can’t inherit both. The one that you received was determined at conception.
Sometimes, it’s possible that a chromosome has gone through a “recombination” process, which could result in a chromosome containing parts of chromosomes from your grandparents. This recombination process happens at least once on each chromosome every time a new sperm or egg cell is created.
Because of all this, you and a sibling with the same parents could easily have slightly different ancestral proportions, as you each would have received different sets of Chromosomes from each parent and the Chromosomes you received may have undergone different recombinations.
Now, imagine this mixing, matching, and recombining of Chromosomes occurring over 10 or more generations of inheritance to create you. The Autosomal DNA Test for your BioGeographical Ancestry Report essentially examines the full spectrum of DNA markers you may have inherited from ALL your ancestors and makes a statistical determination of your Ancestry.
By contrast, a test of your Y-DNA or mtDNA will only trace one specific line of Ancestry. These are the most accurate Ancestry Tests, but are only useful for tracing direct Paternal or Maternal Lineage, whereas the Autosomal DNA Test will give you a broader picture of your Ancestry.
To begin the process of your BioGeographical Ancestry Test, you sent us a sample of thousands of cells (in the form of a buccal/cheek swab) with exact copies of your DNA in each cell.
We extract the DNA from your sample and examine less than .5% of your genetic material. Humans are 99.9% identical on a genetic level, but there are certain regions on each Chromosome that vary from person to person and make us individuals. These small regions are called Single Nucleotide Polymorphisms (SNPs), a small fraction of which can be traced to specific populations. These special markers are the Ancestry Informative Markers (AIMs) we use to estimate your most statistically likely BioGeographical Ancestry.
Our methods of choosing which AIMs to examine is the culmination of decades of genetic research, so we can ensure that we’re only looking at the SNPs most relevant to your Ancestry.
It’s important to clarify that your BioGegraphical Ancestry is not the same as defining your “race” or “ethnicity.” There are many situations where you may be asked to identify your race—perhaps on a job or college application, or when being interviewed about your medical history, or perhaps as part of an awkward conversation with an acquaintance.
There is no exact or widely accepted definition of “race” and perceptions of “ethnicity” can change over time, even on a personal level of interpretation. “Race” and “ethnicity” are not biological concepts, but are social constructs that are influenced as much by cultural factors as they are by genetic ones.
By contrast, your BioGeographical Ancestry is a research-grade estimation of your genetic ancestry, regardless of culture. In this way, your BioGeographical Ancestry is entirely independent of ethnic labels or racial categories. Instead, your BioGeographical Ancestry describes you in terms of your ancestral proportions that are based on human evolution and geographical history.
The percentages in your BioGeographical Ancestry Report represent your genetic affiliations that are driven by both genealogy and anthropology. We will briefly review the anthropological history of human migration that led to the population affiliations we use to identify Ancestry in the next section.
It is generally accepted by archaeologists and anthropologists that the first hominids (bipedal primates) existed as far back as 7 million years ago in Africa. The Homo Erectus species emerged about 2 million years ago, who were about as tall as modern humans, but much more muscular. They were able to verbally communicate with each other and made tools out of stones, such as axes and cleavers.
This prehistoric species thrived at the end of an Ice Age as the planet heated up. Food was widely available as life flourished and H. Erectus was able to migrate in all directions, as several fossils have been found in China, Spain, and Georgia (north of the Caucasus mountains).
The H. Erectus had flatter noses and thicker bones behind their eyebrows than humans today, but it was once believed we evolved from this species. DNA evidence has since caused scientists to believe that modern humans, Homo Sapiens, may have been a separate species who coexisted members of H. Erectus, such as Neanderthals, and that the last of H. Erectus died out within the last 500,000 years.
H. Sapiens have been genetically traced to an origin in Africa sometime between 400,000 and 130,000 years ago. For a long time, the Sahara desert acted as a barrier between H. Sapiens and the rest of the world. However, there were periods in history when the Sahara was green and fertile and provided ample opportunity for H. Sapiens to populate the rest of the world.
The first migration occurred about 125,000 years ago. As with H. Erectus, the Earth warmed at the end of an Ice Age and H. Sapiens were able to cross the Sahara, the Nile, and migrate into the Middle East and along the Mediterranean coast. There was another cycle of cold and dry weather shortly after that, which made food and shelter scarce for these migrants, so it’s possible that this first wave of migratory humans was killed off.
Favorable weather and conditions returned around 40,000 years later and a second wave of human migration occurred as H. Sapiens moved back into the Middle East. ALL of today’s non-African populations have DNA that can be traced back to this second wave of human migration.
Today, we live in a world where people can travel to the other side of the planet in less than 30 hours. While this may seem extraordinary to our ancestors who had to travel at a much slower pace, humans throughout history have actually been even more mobile than we are today. Motivated by the search for food, shelter, and habitable environments, people have moved all around the world to and from particular regions.
Migration slowed down about 10,000 years ago due to the rise of organized agriculture, but it was still common for groups of people to move around. In fact, the largest migration in human history has happened over the last 500 years, thanks to European colonization in the post-Columbus era, the transatlantic trade of enslaved Africans, and now modern day globalization.
The story of human migration starts around 125,000 years ago when modern humans first ventured out of Africa. These early migrants established “founder groups” in different parts of the world that gave rise to present-day Europeans, American Indians, Africans, and East Asians. Thanks to the aforementioned colonialism, slave trade, and globalization, many people in North and South America are admixtures of these founder groups. On the other hand, there are people in some African and Asian nations who have a relatively unmixed BioGeographical Ancestry.
Here is a very basic breakdown of how humans have migrated over the millennia. The DNA of every human on Earth, including your DNA, contains evidence of this migration. Your BioGeographical Ancestry Report will give you an exclusive look into your ancestor’s role in human history.
170,000 B.C.E. – Modern humans evolve in East Africa.
160,000 B.C.E. – The first humans migrate South and West to populate the majority of Africa.
125,000 B.C.E. – Modern humans leave Africa for the first time, settle the Mediterranean shore.
90,000 B.C.E – Humans migrate East and settle China.
85,000 B.C.E. – Human migrations spread along the coastal regions of Southeast Asia and settle Indonesia within 10,000 years.
65,000 B.C.E. – Humans migrate north and west out of the Middle East and Central Asia to Europe.
50,000 B.C.E. – The Cro-Magnon people settle Europe, becoming the earliest Homo Sapiens to do so.
40,000 B.C.E. – Australia is settled by the ancestors of Aboriginal Australians.
35,000 B.C.E – The oldest known cave paintings appear in Indonesia as the first known demonstration of human art.
25,000 B.C.E – Homo sapiens display more artful skill in cave paintings in Europe.
20,000 B.C.E. – Humans migrate to North America via the Bering Land Bridge between modern day Alaska and Northeastern Russia.
18,000 B.C.E. – The peak of the last Ice Age causes many Europeans to retreat into 4 main regions: the Iberian peninsula, Ukraine, Siberia, and the Balkans.
15,000 B.C.E. – Some evidence suggests humans reached South America by boat around this time.
10,000 B.C.E. – The Earth warms up as the last Ice Age ends and humans thrive again in Europe as agriculture spreads.
Your BioGeographical Ancestry Report from CRI Genetics contains an estimate of your specific BioGeographical Ancestry in two formats:
1) A percentage breakdown of your Ancestry from various “Founder Groups” (European, Sub-Saharan African, East Asian, and American Indian)
2) A bar graph that displays our confidence in your percentages, which we will explain in a later section of this manual
It’s important to understand that the percentages in your BioGeographical Ancestry Report are the “maximum likelihood estimate” (MLE) of your Ancestry, or the most statistically likely estimation. It’s possible that the percentages are slightly off, that there is a small bit of Ancestry that’s missing or misreported, but all other combinations of Ancestry are less likely than the estimation we provide you with. The likelihood of these other estimations is represented by the confidence levels shown in your bar graph.
Unfortunately, it’s not yet possible to estimate Ancestry proportions that are definite or exact. Much like predicting the weather, Ancestry proportions are calculated using statistics. When a meteorologist predicts the weather, he or she examines considers various factors: the history of weather systems and what they’ve done before, their current trajectory, and the type of weather system it is (warm/cold front, high/low pressure, etc). A meteorologist uses all of this data available to predict the most statistically likely outcome for the weather and it’s impossible to be 100% correct.
The same is true with Genealogical Ancestry Testing. The only way to be 100% correct (without a doubt) about your genetic Ancestry, we would have to have DNA samples from every ancestor you have ever had going back 200,000 years. This is obviously impossible, so we have to infer your most statistically likely Ancestry by comparing your DNA to thousands of other samples from around the world at various relevant markers.
This is why we call your results a “Maximum Likelihood Estimate,” or the most statistically likely estimation of your BioGeographical ancestry, because it is the best estimate possible. Your MLE provides you with a simple way to describe your genetic heritage. If you want to understand your heritage even further, you can have other people in your family take our BioGeographical Ancestry Test.
Your BioGeographical Ancestry Report has estimations of your heritage from four primary founding populations:
These “founding populations” we use for your BioGeographical Ancestry Report refer to large groups of people who share Ancestry connected to certain geopolitical areas with “blurred boundaries.”
For example, the broad spectrum of people covered by the European founding group is based on evolutionary and anthropologic studies that show common ancestry and migration patterns. As we mentioned earlier in this Manual, humans migrated out of Africa around 50,000 years ago to settle the “Fertile Crescent” area of the Middle East—the Mesopotamian region between the Tigris and Euphrates rivers that stretched from Lebanon and Israel on the Mediterranean coast to Iraq and into Iran.
This founding population in the Fertile Crescent eventually branched out of the Middle East in different directions roughly 40,000 years ago. Some migrated to Europe, others migrated to South and Central Asia. People living in the Middle East spread out of the Fertile Crescent again about 10,000 years ago, blending with the European population that had now been there for 30,000 years. This same migration out of the Middle East likely blended more with South Asian populations as well.
Because of this complex history of migration, people in Europe, South Asia (India), and the Middle East often share common Ancestral markers dating up to 50,000 years ago. South Asians tend to have a lower level of “European” markers than Middle Easterners, but the shared markers are still substantial: On average, South Asians show about 58% European Ancestry, whereas Middle Easterners exhibit between 80-90%.
On a similar token, the American Indian founding population requires more explanation due to their migration history, as there were three major waves of migration into the Americas.
The first wave of migration started as far back as 30,000 years ago and brought the largest group of American Indians into the Western Hemisphere. These people were Amerind speakers, which is an early language that several Native American tribal dialects are derived from (similar to how French, Spanish, and Italian are all derived from Latin). This first group of American Indians crossed the Bering Strait Land Bridge and migrated down the Pacific coast of the Americas all the way to the southern tip of Argentina.
The second wave of migration into the Americas started around 16,000 years ago and brought in Na-Dene (pronounced “nah-dinnay”) speakers, who contributed to Native populations in Central America, Mexico, the United States, and Canada. Several well-known tribes have dialects derived from this early language, including the Navajo and Apache.
The final wave of migration into the Americas happened just 6,000 years ago and brought in speakers of Inuit languages, more commonly known as “Eskimo-Aleut.” This group of American Indians almost exclusively lives in the Arctic regions of North America, but speakers of similarly derived languages can also be found in Northern Russia and even as far as Denmark in Europe.
There is no definitive beginning, end, or break between any of these migrations into the Americas and many of their genetic markers are shared across all of these three founding groups. Due to generations of mixing between tribes and how relatively recent the migrations occurred, tracing specific Indigenous American Ancestry by region can be difficult.
Because of these complex migration factors, many Europeans, Middle Easterners, and Asians can exhibit American Indian Ancestry—as much as 10%—even if they and their ancestors technically never set foot in the Americas.
For similar reasons, people with European heritage should take into consideration the fairly “recent” conquering of Europe by Roman (Italian) armies when examining their BioGeographical Ancestry. The Roman Empire spanned much of Europe—including England, much of the Middle East, and parts of Northern Africa. This occupation accounted for more than 1,000 years of intermingling between multiple genetic sources.
It goes without saying that individuals with Ancestry in a certain founding population may exhibit some of the physical characteristics associated with that population. An obvious example would be someone with significant African Ancestry (80% or more) who has darker skin than someone with significant European Ancestry (80% or more).
On average, an individual who has physical features associated with a certain population group will usually have at least 30-35% Ancestry with that group. The percentage of genes that determine physical appearance is very small compared to the total number of genes in a person’s genome.
The BioGeographical Ancestry estimation we have determined for you is extremely accurate. The latest genetic reading equipment, our patented DNA analysis software, along with our experience and techniques allow us to achieve accuracy greater than 99.99%.
There are times when we aren’t able to read certain markers on your DNA sequence, which can very slightly reduce the accuracy of your BioGeographical Ancestry Report, but the effect is minimal. These are called “failed loci” (FL) and they can occur for a few different reasons:
1) A small region of your chromosome could be missing or be a different sequence character than most. Chromosomal positions vary from person to person naturally, so this is not uncommon. It’s simply evolution.
2) Sometimes, a FL could be the result of something as simple as us not getting enough DNA from the sample you sent us. Some markers are more sensitive to this type of event than others.
If there we came across several FLs while analyzing your DNA, it could significantly alter your results, but we wouldn’t release a report like that. We hold ourselves to high standards—if we can’t accurately estimate your Ancestry with the sample you sent us, we will either send you another DNA collection kit for free, or we will give you a refund as part of our Efficiency Guarantee.
As we’ve mentioned before, the statistical nature of your BioGeographical Ancestry Report allows for some variability in your results. Without the ability to time-travel and gather DNA from every human going back 200,000 years, it’s impossible to perfectly estimate a person’s Ancestry, but we can accurately estimate your most statistically likely Ancestry based on genetic and anthropological evidence.
Much like meteorologists predicting the weather, our understanding of the history of human migration, the admixtures of various populations over generations, and the reference data from populations around the globe, we can accurately estimate an individual’s BioGeographical Ancestry.
For those interested in doing further research on their own, we recommend the following resources:
Books
Websites