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Schematic representation of the double helix (spiral staircase) in DNA.

Written sources from before 1500 are scarce. Dutch people with an immigrant background usually have to make do with written sources that go back even less in time. As a result, the search for ancestors comes to a halt at a certain point. DNA research can then offer a solution.

It is possible to trace early ancestors based on DNA research. DNA research can also provide clarity about the kind of relationship that living persons have with each other. DNA testing can also offer a solution in situations where a written source is not considered to be sufficiently reliable.

On this webpage the different methods of genealogical DNA research are explained. The results obtained by webmaster Peter van Boheemen serve as an illustration. First of all, it describes who the ancestors of the European population are.

Our ancestors

About 7 million years ago, the ancestors of modern humans split from the line, from which our closest relatives, the Chimpanzees, also sprang. The new line also has all kinds of divisons. Almost all of these lead to human forms that no longer exist.

About 1.9 million years ago, the line of the upright walking Homo erectus originates, which spreads across Africa and large parts of Euro Asia. Homo erectus is therefore the first ancestor to leave Africa. But Homo erectus cannot survive either.

About 600,000 years ago, Homo sapiens appeared as a split-off from Homo erectus. About 100,000 years later, another human form emerges from the Homo sapiens line. This is the Neanderthal who migrates to Europe and settles in a narrow strip that runs from France to the Near East. They live in a time when large parts of Europe are periodically covered with ice sheets,
The Neanderthal line is also split off in the form of the Denisova, which settles in Asia and later disappears.

In the Sub-Sahara there is no mixing of Homo sapiens with other human forms. From here, the Homo sapiens spread across Africa, including to Morocco, where remains of about 300,000 years old are found in 2017. In Africa there is a completely different climate than the Neanderthal in Europe at that time has to deal with.

Between 400,000 and 220,000 years ago, early Homo sapiens migrated to Europe, where they mingle with Neanderthals. This explains that the late Neanderthals have traces of Homo sapiens in their DNA. There is no admixture in Asia, so the Denisovas remain closely related to the early Neanderthals. However, the early migrated Homo sapiens do not survive in Europe.

About 60,000 years ago, Homo sapiens emigrated again from Africa to Europe and Asia and then to America and Australia. This leads to the creation of the current world population. In the initial phase, some mixing takes place with Neanderthal and Denisova. Today’s inhabitants of the world still have traces of this in their DNA.

About 40,000 years ago, Homo sapiens migrated via the Danube Delta to Central Europe, where a cold climate still prevails. The Neanderthal dies out shortly afterwards, giving Homo sapiens supremacy in Europe. The Homo sapiens live there as a hunter-gatherer. He also manifests himself as an artist by making jewelry, statuettes and cave paintings.

Between 24,000-18,000 years, Homo sapiens experience extreme cold. They then withdraw to SW Europe (Spain and Portugal). When the weather warms, a return to Central Europe takes place. People from the Balkans also come there. Subsequently, a homogeneous population of technically advanced hunter-gatherers with blue eyes and dark skin arises. About 13,000 years ago a stadial (cold period) follows, but this is not extreme.

From 12,000 years ago, the climate is getting friendlier. In the Near East, the first forms of agriculture (arable farming and livestock farming) then arise. This led to a migration of farmers from Anatolia to Europe 8,000 years ago. The hunter-gatherers with their considerably darker skin then retreat further and further in the direction of England and Scandinavia.

A third and final migration to Western Europe occurs about 5,000 years ago. This time from the Pontic Steppe (region north of the Black and Caspian Sea). They are nomadic herders who are very mobile because of the use of horses and wagons and are already able to work bronze. At the time of their arrival, it is suspected that Central Europe is sparesely populated because of plague outbreaks.

The foregoing explains that three dominant genetic components can be distinguished in the DNA of today’s Europeans. These come from the hunter-gatherers, the farmers from Anatolia and the herders of the Pontic Steppe.
The following nuance is in order. The DNA of the people who differ most from each other worldwide, is 99.8% identical. Hence, within the group of Europeans, differences in genetic origin can only be determined with the help of very advanced techniques.

Source: Johannes Krause and Thomas Trappe. The journey of our genes, A story about us and our ancestors (in Dutch; also available in German). ISBN 978-90-468-2681-2, p. 285 (Nieuw Amsterdam 2020).

DNA types

There are two types of DNA. The most important is the DNA that is in the nucleus of every body cell. This DNA consists of 23 chromosome pairs. One of them is the so-called sexual chromosome pair. In case of a man this consists of a Y and an X chromosome and in case of a woman of two X chromosomes. The other 22 chromosome pairs together are called the autosomes (non-sexual chromosomes).
The DNA in the autosomes is called atDNA for brevity. The DNA in the sexual chromosomes is abbreviated to Y- and X-DNA.

There is not only DNA in the nucleus of every cell. DNA is also present in the mitochondria, but to a much lesser extent. Mitochondria are organelles that are present in the plasma of a cell. They provide the energy for a cell. The DNA in the mitochondria is called mtDNA for brevity.

Research based on atDNA

In autosomal research, the DNA is analyzed in all chromosomes, except in sexual chromosomes X and Y. For each person, this yields a unique combination of DNA characteristics.

For people related very closely to each other, there is a great similarity in the DNA profile. However, the farther the relationship, the less similar. This dilution is fast. As a result, research based on atDNA is not well suited for proving a distant relationship.

In a child, half of the atDNA comes from the father and the other half from the mother. This rule does not apply to earlier generations. For example, a child does not receive exactly 25% of the atDNA from every grandparent and not exactly 12.5% ​​from every great-grandparent. This is a consequence of the exchange of DNA pieces (crossing pver) between the two chromosomes of the same chromosome pair. This happens during the production of egg and sperm cells. The exchange is called recombination.

Recombination explains that someone has no atDNA from some of his or her 128 ancestors born six generations earlier. As a result, only half of the ancestors of ten generations ago is present in the atDNA. In general, atDNA is only useful for searching for ancestors born after 1700. It is therefore recommended to have several family members participate, so that a relationship can be approached from different sides.

The extent to which atDNA is common is expressed in the number of equal pieces of DNA and its total length, measured in centimorgan (cM). There are tables indicating how many centimorgan of corresponding atDNA may be expected in a certain family relationship, such as a cousin or great-uncle.

Webmaster Peter has no experience yet with checking, for example, the relationships emerging from his pedigree chart, and tracing members of the Van Bohe(e)men family which are still unknown to him.

As discussed above, three dominant genetic components are present in the atDNA of today’s Europeans. In case of webmaster Peter, the distribution over these components is as follows:

  • component                 hunter-gatherers                                        56 %
  •         ,,                                farmers                                                              35 %
  •        ,,                                shepherds ftom  the Pontic Steppe      9 %
  •       ,,                                 others                                                                     0 %

The distribution indicates that webmaster Peter knows many genetic characteristics of the hunter-gatherers who settle early in Europe.

Research based on Y-DNA

In 2007 webmaster Peter takes a first step by participating in the Dutch project ‘Sons of Adam in the Netherlands’ (see Publications). A second step follows in 2017 by participating in a comparative DNA study together with four other male members of the Van Bohe(e)men family.

Both studies involve the DNA in the Y chromosome (Y-DNA). It benefits from the fact that a son basically has the same Y-DNA as his father. Therefor every present man should have the same Y-DNA as the progenitor(s) of Homo sapiens.

When sperm cells are produced, a small change in the Y-DNA can occur which is passed on to the offspring of the respective man. As a result of a series of such copying errors (mutations), there are differences between present-day families in composition of the Y-DNA.

Comparative DNA research
Five male family members particpitated in the aforementioned comparative DNA study. They have a common ancestor who is born around 1760. The analysis results demonstrate that all five participants have the same mutations in the Y-DNA. The five are therefore not only related in a legal sense, but also in a biological sense. At the same time, the comparative DNA research strengthens the reliability of the family tree created (and also the family feeling among the participants).
Additional research with participating male relatives from previously split-off family branches can further strengthen the accuracy of the family tree. If there is interest in participating, please let me know. This can be done using the Contact Form.

Migration by ancestors
Based on worldwide research on human fossils, it is now known for many mutations where and when they took place. This makes it possible to trace the migration route traveled by the early ancestors. However, it is not possible to go all the way back to the progenitor(s) of the Hono sapiens who lived about 600,000 years ago. The current knowledge about the mutations in the Y-DNA does not make it possible to go back further than the so-called Y-chromosomal Adam (150,000-300,000 years ago). Regarding his first descendants, we have to deal with a black hole as we know it in astrophysics.

The analysis of the Y-DNA of webmaster Peter has shown, that he belongs to Y-haplogroup R1b-L48.  A haplogroup consists of men with the same mutations in their Y-DNA.
Haplogroup R1b-L48 is found to a large extent in the northwestern part of The Netherlands. Here about one out of five men is part of this haplogroup.

Map with predicted frequencies of hapolgroep R1b-L48 (E. Altena, The Dutch Y-chromosomal landscape, European Journal of Human Genetics, 2019).

The mutations in webmaster Peter’s Y-DNA are arranged in the following overview by time and place. The overview makes broadly clear along which route the ancestors of webmaster Peter migrated from Africa to his birthtown Voorburg.

On the left side of the overview, the generation numbers of different ancestors are mentioned. Y-chromosomal Adam mentioned above has generation number 1. For convenience, given the aforementioned bandwidth, it is assumed that he is born in Africa 230,000 years ago.
At the bottom of the overview webmaster Peter is listed with the generation number 6900. The number 6900 is based on the assumption that, on average, three male generations occur within a century. For a period of 230,000 years, this amounts to 6,900 generations.

Patriliniarity of webmaster Peter van Boheemen from Y-chromosomal Adam (National Genographic).

Under the Y-chromosomal Adam, mutation P305 is mentioned in the overview. This mutation takes place in Africa about 100,000 years ago. It is the earliest mutation that does not occur in all present-day males and is therefore still seen as the first split-off in the male male pedigree.

The later mutation P143 marks a crucial moment. Because it is a mutation that occurs outside Africa. It happens to an ancestor who lives 60,000 years ago in the Middle East (Saudi Arabia, etc.). He belongs to the group that shortly before leaves Africa due to drought and follows wildlife to green, more northern areas. Presumably they cross from present-day Ethiopia to the Arabian peninsula.

Between 45,000 and 20,000 years ago, roughly speaking, the ancestors migrate to Russia via Afghanistan, western China and Kazakhstan. Less than 4600 years ago, migration to Western Europe, coincides with the spread of agriculture.
The latter fact does not contradict the earlier observation that in the atDNA of webmaster Peter the component ‘hunter-gatherers’ predominates and not the component ‘farmers from Anatolia’. This is because the atDNA reflects the origin of all of the ancestors of webmaster Peter, while the Y-DNA refers only to the ancestors in the straight paternal line.

About 700 years or more ago, the then ancestors settle on the border of the current municipality of The Hague with the current municipality of Westland. The overview ends with webmaster Peter who is born a short distance away in 1950.

A more detailed analysis will undoubtedly possible in the near future.

Spread of Y-haplogroup R1b-L48  to which webmaster Peter van Boheemen belongs (National Genographic).

Postscript (same for mtDNA)
Two male persons with the same series of mutations in their Y-DNA do not necessarily belong to the same present-day family. The most recent mutation may have occurred thousands of years ago. The forefather to whom the most recent mutation occurred is the common forefather. Apparently, several present-day families originates from his descendants.
For example, the aforementioned project “Sons of Adam” demonstrated that webmaster Peter van Boheemen has the same series of mutations as another participant. The two patrilinearities that go back to around 1500, however, have no agreement. All this means that another indication (for example, a written archive source) is required to prove a close relationship, in addition to an agreement in the series of mutations in the Y-DNA.

Research based on mtDNA

It is remarkable, that brothers and sisters have the same DNA in their mitochondria as their mother. The mtDNA of a father is not passed on.

Just as with Y-DNA, mutations occasionally occur in mtDNA. This makes it possible to trace someone’s foremothers on the base of mtDNA. In this way there ca n also be determined  wether a female lineage based on written archival sources is also correct in biological sense.

The analysis of the mtDNA of webmaster Peter has shown, that he belongs to mt-haplogroup H1c13. The seperate mutations  are arranged in the following overview according to time and place. This makes it broadly clear along which route webmaster Peter’s formothers migrated from Africa to his birthtown Voorburg.

On the left side the generation numbers of the different formothers are mentioned. Thereby mitochondrial Eve has number 1. She is a same metaphor as Y-chromosomal Adam. It is assumed that Eve is born in Africa about 200,000 years ago.
At the bottom webmaster Peter is listed with generation number 8000. The number 8000 is based on the premise that, on average, four female generations occur within a century. For a period of 200,000 years, this amounts to 8,000 generations.

Matriliniarity of webmaster Peter van Boheemen from mitochondrial Eva (National Genographic).

Mitochondrial Eve lives in the Old Stone Age in present-day Ethiopia, Kenya or Tanzania. She probably has dark skin (as a protection against sunlight), dark hair and brown eyes.
Fossils from SW Ethiopia (195,000 ± 5000 years BP) include a young woman measuring 162-182 cm in length and weighing about 70 kg. Other fossils are also found near her human bones. These give an idea of ​​the way of life along the Omo. river The people eat fish, birds and anything else that can be collected in the surrounding swamp, grassland or forest. They make their utensils from flint and from the bones of birds and wild cattle.
At that time. it is much humid in the Omo valley than nowadays because of the Saalian Ice Age, when the northern half of the Netherlands is covered with ice and the Veluwe moraines are formed. The greater cold in the north leads to more rain in Africa. The Saalian lasts until about 126,000 years BP.

Under Eve, haplogroup L3 is mentioned, which is characterized by a mutation taken place 67,000 years ago in East Africa. Then haplogroup N follows, which is based on a mutation occured 60,000 years ago near the border between East Africa and Saudi Arabia. Driven by drought in the Sahara, members of haplogroup N travel through the basin of the Nile to the Sinai.

Until 10,000 years ago, the frmothers stay in the Middle East. Afterwards they move to Europe. About 300 years or more ago they settle in the Dutch province South-Holland. The overview ends with webmaster Peter who is born in 1950 in Voorburg.

A more detailed analysis will undoubtedly become available in the near future.

Spread of mt-haplogroup H1c to which of webmaster Peter van Boheemen belongs (National Genograpic).

Research based on X-DNA

As mentioned earlier, a woman has two X chromosomes. One comes from her mother and the other from her father. A man only has one X chromosome, besides one Y chromosome.

When a father passes on his X chromosome to an descendant, he gets a daughter. All his daughters will receive therefore the same X chromosome from him. DNA research based on X-DNA can therefore be used to determine whether two women descend from the same father.

A mother does not pass on one of her two X chromosomes to a child, but a mix of both X chromosomes. Two children of the same mother therefore do not receive an identical X chromosome. One way out is that two children of the same mother do have the same mtDNA.

 

As mentioned earlier, a woman has two X-chromosomes. One cmes from her mother and the other from her father. A man has only one X-chromosome, besides one Y-chromosome next to it.

When a father passes on his X chromosome to an descendant, he gets a daughter. All his daughters will therefore receive the same X-chromosome from him. Research based on X-DNA can therefore be used to determine whether two women descend from the same father.

A mother does not pass on one of her two X chromosomes to a child, but a mixture of both X-chromosomes (due to the phenomenon of recombination as discussed earlier). For that reason two children of the same mother do not have the same X-chromosomefrom her (unless they are identical twins). A way out for this is that two children from the same mother have the same mtDNA. .