I have one large family example and one small family example
that are pretty good going back. My goal
is to determine a way to approximate how many descendants a degree of
great-grandparent might have. They
obviously will vary and I am sure my families are not the absolute lower and
upper bounds and my sample size is 2 lines and 8 generation differences. So the small sample size makes this example
very inaccurate as a true average, but it could be the basis to build a better
sample size.
This sample uses my Miley and Schmitz lines, again, one
family line for the last 5 generations has been fairly small, and other family
line for the last 5 generations has been fairly large.
The data:
Miley Line:
Generation and descendant count, with a percentage of each
generation to the last:
Miley
- person: descendants: percent
·
Gary:10 (my dad)
·
Dick: 16 : 160%
·
GLS: 48 :300%
·
James Jr: 80: 166%
·
James Sr : 199 :249%
Schmitz-
- person: descendants: percent
·
Darlene: 10 (my mom)
·
Don: 51 : 510%
·
JWS: 72 : 141%
·
Phil: 186 : 258%
·
Nik: 391 :210%
We can now see our percents vary wildly
and the percents between generations descendant counts range from 510% to 160%
in our example. This is a large swing,
but notice that the numbers do not appear to be progressive and the percentage
numbers do not appear to be exponential while the descendant counts clearly
are. This means that an average should
be possible but realize our sample size is only 8.
Our set: 160%, 300%, 166%, 249%, 510%, 141%, 258%,
210%
Average: 249.25%
Meaning, in my example each generation’s
descendants is best guessed as 249.25% of the previous generation.
We can extrapolate this to X
generations to get a very rough guess at how many there might be:
Generations and descendant count
guesses based on my small example:
1 (my dad)
|
10
|
2 ( gpa)
|
24.925
|
3 (gr-gpa)
|
62.1255625
|
4
|
154.8479645
|
5
|
385.9585516
|
6
|
962.0016898
|
7
|
2397.789212
|
8
|
5976.489611
|
9
|
14896.40035
|
10
|
37129.27788
|
11
|
92544.72513
|
12
|
230667.7274
|
13
|
574939.3105
|
14
|
1433036.231
|
15
|
3571842.807
|
16
|
8902818.196
|
17
|
22190274.35
|
18
|
55309258.83
|
19
|
137858327.6
|
20
|
343611881.6
|
