My ancestors

As you probably know, our species, homo sapiens, evolved, 200.00-150.000 years ago in Africa. From there they migrated all over the world. All humans living now, have  common maternal  and paternal ancestors.

How do we know this? By studying mutations in our DNA!

The idea is simple. Every now and then mutations occur in our DNA. If a mutation occurs in the DNA of an individual, will this mutation also be present in the DNA of its offspring? In the reproductive process the genes of father and mother are mixed, so that is difficult to say. There are however two exceptions!

One is the Y-chromosome, which inherits exclusively from father to son.The other one is the DNA in the mitochondria, the power plants of a cell. They come from the egg, and therefore from the mother.

By studying the mutations in the Y-chromosome we can trace back our paternal lineage to the Y-Chromosomal Adam. And in the same way, studying the mutations in the Mitochondrial DNA, we  finally go back to Mitochondrial Eve

Here are the approximate migration patterns for the paternal lineage. When you click on the picture, you will get an enlargement, where you can see the numbers in the various branches, like M173, M175, etc. This are the markers for specific mutations in the Y-chromosome. In the table estimates are given when this mutation took place. People with the same mutation in their genes are said to belong to a haplogroup

Last year, surfing the Internet, I found the website of the Genographic Project, managed by National Geographic. For 99 USD you could order a DNA ancestry kit to determine either your paternal or your maternal lineage.

As I was just reading the impressive masterpiece by Richard Dawkins, The Ancestor’s Tale, I became interested and ordered a kit. Here I am taking a swab to collect some DNA from my cheek.

The kit contains a code number that you can use to check the progress of the analysis.

After about two months I got the result. My haploproup was R1B. Nothing special actually, the majority of Europeans belong to this group…:-)

 

Here is the migration path of my (paternal) ancestors. About 50.000 years ago my paternal ancestor (M168) left Africa. His descendants traveled through the Arabian peninsula to Central Asia. They were hunter-gatherers, following the big game through the savannas, until they (M45) reached the big mountain ranges of Hindu Kush and Himalayas.

About 30.000 years ago, a branch split off with a new mutation (M207) and traveled to the West.  Keep in mind that they were not tourists, their movements were mainly determined by climate change and the availability of food!

In Europe this “Cro-Magnon” tribe met the Neanderthal people, which they outcompeted by their better skills and tools.

So that is my paternal lineage. Actually we ordered two sets, also one for Aric. His haplogroup turned out to be O, also nothing special, shared by the majority of Chinese in Southern China. It is interesting to see where our lineages split! In the image below I have combined our migration routes. The split occurred about 35.000 years ago in what is nowadays Tajikistan. In those days and in that region there has lived a man who is the (male) ancestor of both Aric and me. I find that fascinating.

So fascinating, that we ordered two more sets, this time to find out more about our maternal lineage.Here are the results combined in one picture.

Aric’s mtDNA haplogroup is D, mine is H Our common great……….great-grandmother migrated from Africa about 70.000 years ago. Still in Africa, about 65.000 years ago a split occurred, much earlier than in our paternal lineage. Aric’s maternal ancestor migrated far north to central Asia and Siberia. Members of haplogroup D eventually reached the Behring street and arrived in the Americas, about 15000 years ago

My maternal ancestors did not migrate as far east as my paternal ones, they remained in West-Asia and later migrated north across the Caucasus mountains into South-Russia and from there into Europe.

It is possible to make a more detailed (and more expensive) analysis of the mutations in the DNA, but for us this is enough. We know now, that we are family, LOL.

Mind you, our common maternal and paternal ancestors were NOT married, they did not even live in the same time! If you want know how that is possible, you should read Dawkin’s book.

4 thoughts on “My ancestors

  1. Fascinating! So that does not mean that your relationship is incestuous, right? 🙂 Well, it is easy to accept that everyone eventually goes back to common ancestors, that is pretty obvious, but this is a different concept, of a Most Recent Common Ancestor, which was tens of thousands of years later, if I understood the Wikipedia link.

    • Yes, it is fascinating, and also complicated, often a lot of statistics and mathematics, read Dawkins..:-).
      1. Don’t worry about incest..:-) Sexual reproduction means mixing of genes (except Y-DNA and mtDNA) , so after many generations you will have less and less of the original genes of these paternal/maternal ancestors.
      2. Suppose your mother’s father also had a son (your uncle) who married and had children. They are your cousins. But you share neither your Y-chromosome, nor your mitochondrial DNA with them!
      3. Therefore to find a common ancestor (in the general sense) with anybody else, you don’t have to go back so far. An estimate is about 5000-15000 years ago. Some genealogists say that for example all Europeans have a common ancestor around 1400 AD!

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