DNA Testing Basics

[Ninurta]

I chose CRI Genetics for my family's DNA testing, mainly because of the expertise of the scientists running the company and they give reports on ancestry, allergies, extensive other health reports, etc.

CRI Genetics (Cellular Research Institute, Genetics Department) is led by Alexei Fedorov Ph.D., a molecular geneticist with over 35 years of experience studying DNA. A former apprentice to Nobel Prize winning scientist Walter Gilbert, Alexei has created a proprietary DNA analysis algorithm using the latest breakthroughs in genetic science. His lifetime goal has been to advance mankind’s understanding of the human genome into new frontiers.

and this ...

CRI Genetics is an advanced team of scientists who work together based on the latest research in genetics, anthropology, and the social sciences. We are passionate about providing our customers with accurate (and interesting!) DNA-based reports. 

We use proprietary DNA analysis algorithms designed by renowned molecular geneticist Dr. Alexei Fedorov, Ph.D., who was apprentice to Nobel Prize-winning scientist Walter Gilbert at Harvard University. Alexei’s algorithm uses 527,414 hand-chosen genetic markers when analyzing someone’s ancestry.
That means that you get fascinating Ancestry reports and useful Health reports that are both detailed and accurate. We’re confident you will learn something new about yourself when you begin your journey with us! 

Now some of the customer comments almost come off as they can't believe the data because it's not the family history handed down through generations etc. 

But for me and my family, all I can say is whatever they are doing at CRI they are getting most of it right for us. 

They will also destroy all your DNA data if you just ask them.



I also bought the advanced timeline and I searched the internet to have a look at the peoples of those places looking for family physical traits, and I found matches. Very interesting.

Interesting information, and good solid explanations of some key concepts.

The mathematics of DNA have always fascinated me. ALL of your DNA comes from "somewhere", but not all of the DNA from that "somewhere" ever actually makes it to you. It's one of the key reasons why DNA ancestry is not genealogy. After about 7-10 generations, some of your ancestors completely disappear from your genome, yet are still genealogical ancestors - they are just no longer genetic ancestors. What's more, every one of those who disappears from your genome takes with them ALL of the DNA of ALL of their ancestors, meaning that there are huge gaps in everyone's DNA where they have ancestors that will never be found, from places they will have no clue about.

Another, perhaps related aspect of the mathematics of genealogy that intrigues me is the fact that as one goes farther back, each generation doubles in size... but also, as one goes farther back, the human population of Earth DECREASES in size. This means that, at some point in one's history, there will be more "slots" in his or her ancestry for that generation than there were people alive on Earth... and that means that some people start appearing in multiple places in one's family tree in that generation.... and the farther back in time one goes, the worse that phenomenon gets.

For myself, having calculated an average generation time of 28 years in my own family tree, that point of equilibrium is reached at between 28 and 29 generations back, between the years 1176 and 1204 AD. farther back than that, and the representation of some individuals in my family tree explodes. at 29 generations back, around 1176 AD, I will have had 536,870,912 ancestors in just that generation, while the human population of Earth at that time was around 340,000,000 people - and that means that IF I were related to every living person on Earth at that time, each one of them would appear an average of 1.579 times in my family tree at that generation.

At 32 generations back, about the time of King Henry I, say 1092 AD, each ancestor would appear in an average of 14.46 places on my family tree.

There just aren't enough people on Earth to put a unique individual in each space. At 47 generations back, around the time of Charles Martel, circa 728 AD, If I were related to everyone alive on Earth at that time, each person would appear an average of 167,545 times.

Those numbers are actually low, however, when one takes into account the fact that Australian Aborigines, for example, had been isolated from the rest of planet Earth for 40,000 years, so of course none of them could possibly appear as my direct ancestors until the early 1600's. So they will not be represented. Other isolated populations are the same, such that there is no way that any one person could possibly be related to everyone alive on Earth at that point. The pool of available ancestors shrinks on that account, meaning that each one possible will have had to appear MORE often in any given generation.

Now if we take into account the fact that anyone appearing once in the family tree is likely to appear multiple times, perhaps as many as hundreds of thousands of times, and then factor in the fact that some of those tree limbs disappear completely between 7 and 10 generations back, what we get is a necessarily skewed view of our geneaological ancestry, the people who contributed to making us who we are, but we also get a weighted view of the ones whose traits we actually carry.

That's for the autosomal DNA, the DNA from the cell nuclear chromosomes. Mitochondrial and Y-chromosome DNA is different in that it relates an unbroken line way back into the mists of antiquity... but only along ONE single direct line each, out of hundreds of thousands represented by the autosomal DNA. my paternal Y-DNA, for example, goes back to the Balkans, between 5000 and 5000 years ago. It represents a people who developed bronze weapons, and used them to invade to the west into Europe spreading bronze and farming as they went along conquering. My maternal mitochondrial DNA, in contrast, goes back to around 28,000 years ago, and represents paleolithic hunter-gatherers in Europe... the people that the Bronze folk conquered. Yet neither of those groups appears to be represented in the autosomal DNA. They just dropped out over the generations, and would be entirely unknown and unrepresented in my DNA if not for those two single bloodlines.

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