What part am I??

I was thinking about the Math part from my previous blog, Math & Genealogy - it does a family good, and hoping I didn't put anyone off, even though it is amazing.  Still, I am going to risk it one more time...  with some more math - fractions.    YEAAAHHHH!

Considering many people always want to know "where they came from", I hope I can help you answer this question.  This fundamentally means we want to be able to trace back our roots to some geographic location and/or ethnologically unique place in time, and literally, you can do this in a few simple ways.

First, you can start filling in the blanks of your family tree, by digging into history of your past, with as much as you know, and/or talking with your relatives.

Second, you can have a Genealogist (like me), do a family tree for you (if interested, contact me).

Lastly, you can get a DNA test, and see where your genes really started, going back thousands of years.   I can tell that a DNA test is going to really tell you details that your great Aunt Ninnie can not!  


So, once you have the family tree, we just need to know the country your ancestors were born in and what generation they came from.   To keep this simple, I am going to demonstrate how this works for only 3 generations, to my great-grandparents.   Mine is actually very easy, at least to identify, since in the last 3 generations, I have only 1 great-grandparent who was born in another country, Germany.   To figure out what fraction of German I am, I simply use the 2^n formula for the generation.   When I do this, I get 1/2^3 or 1/8 German.   That's it...  I am 7/8's American and 1/8 German - WOW!   That explains why I can only speak German 1/8 as good as English ;(

Its easier to see the math in action, if you look at the table below.  GGMa is German.

Gen

Tot

%

Me

0

1

Me

Parents

1

2

0

Pa

Ma

G Parents

2

4

0

G Pa

G Ma

G Pa

G Ma

G G Parents

3

8

1/8

GG Pa

GG Ma

GG Pa

GG Ma

GG Pa

GG Ma

GG Pa

GG Ma

One condition I would apply is that in order to consider your "origin" and therefore, your paternal birth countries, you should at a minimum, expect the family to be living in that country for no less than 3 generations.   Therefore, for me, my great-grandmother, and her parents, and her grandparents, would need to also have been born in Germany.  To do this helps eliminate cases where grandparents were born in county A, then their children were born in country B, and their grandkids were born in yet another country C.   It makes the fractions a bit impossible, not to mention really confusing the grandkids when you get a number greater than 100%.   For example, if you do this and you get a number like 150% Swedish and 25% French, you know something didn't go right...in the number calculations!

Lets take a look at a hypothetical example, to see how easy it is.   Lets say my paternal GGPa was born in Brazil and GGMa born in Peru (and have 3 generations past).  In addition, lets say my maternal GMa was born in Germany, and my paternal GPa was born in the UK, we would have the following table.  

Gen

Tot

%

Me

0

1

Me

Parents

1

2

0

Pa

Ma

G Parents

2

4

1/4+1/4

G Pa

G Ma

G Pa

G Ma

G G Parents

3

8

1/8+1/8

GG Pa

GG Ma

GG Pa

GG Ma

GG Pa

GG Ma

GG Pa

GG Ma

This means I would be 1/8 Peruvian, 1/8 Brazilian, 1/4 UK,  and 1/4 German.    Notice I didn't include the maternal GGPa/Ma?    You want to count the "latest generation", in this case my maternal Gpa/Ma.

As you start looking at trees going back further, you may see that each generation gets smaller and smaller since we keep using the formula, 1/2^n.   In fact, the 4th and 5th generations are just 1/16 and 1/32, respectively.   Either way, we are still a fraction of those ancestors from hundreds and thousands of years ago and it is important to remember them and realize we wouldn't be here without them. 

As always, your cousin.

Did you say 4.3 billion people - are you sure?!?

One of my favorite movies is "Back to the Future" and one of my favorite scenes was when Doc Brown realizes the enormous power required to make the Time Machine work.   He starts getting really excited and repeating the amount of energy, or 1.21 gigawatts, while Marty asks what a gigawatt is.   

gig·a·watt/ˈgigəˌwät/ - A unit of electric power equal to one billion (109) watts.

 

Just like Doc Brown, I was really a bit concerned when I determined in my last post that I have nearly 4.3 billion ancestors, starting from 100 AD..  That just sounds a bit large, so I started looking closer at the numbers and the assumptions.  I kept getting the same number, and even better, the Population Reference Bureau, determined that around 100AD, the earths population was about 300 million.    Further still, the total number of people who have ever lived since the beginning of time, is only estimated to be about 108 billion!

So how is this so far off?    

Well, if we start with the assumed total of 300 million around 100 AD, that means we get about 28 generations.   But even that seems a bit small, since that means each generation is about 70 years, and that is a huge stretch and for now, I am going to look into this further, as something is off.


In showing this analysis, I hope the point hasn't been lost in the math.   While researching your family line, it is important to make assumptions about the story being told, but to be clear and document it in detail, for you to later review and or others to follow.   It is a good practice, to always annotate your sources, state your assumptions and keep clear notes for reference.   This helps others in the future, as well, and they can either confirm or refute what you published.   .
 
I hope my example was helpful and beneficial.  Stay tuned for more about the mystery of the "overpopulated" world in 100 AD.

Your cousin, Brian

Math & Genealogy - it does a family good!

If you were born on this planet, in the last 80,000 +/- a few years, you may not know it, but we are all pretty much the same.   In fact, we are 99.5% genetically the same..  And rather than bore you about the birds and bees, and genetics, let's talk about something really neat - math!   A subject we can all "relate" to in terms of genealogy and families.