Sunday, February 26, 2012

Number of Ancestors



In a previous entry we have discussed the correct way to name our more distant ancestors on each generation. We will complete that entry adding the theoretical number of ancestors for each generation.  Genealogist call this chart a “Chronologic-Genealogic” Table.
We talk about theoretical number of ancestors because we know the marriage between relatives reduces dramatically the number of ancestors. The happily reigning Juan Carlos I is an extreme example of this situation, as on this 8th generation (128 ancestors) he descends 22 times from King Charles III, 22 times from his brother Philip (Duke of Parma) and finally 22 times from Philip’s wife that was also a Bourbon, daughter of Luis XV, King of France. More than half of King Juan Carlos I on that generation descends from the same Bourbon ancestor. Of course this is an extreme example, but in rural Spain marriages usually happened in the same village; therefore marriages between relatives (even first of second cousins) were very common.
Generation
Estimated
Year
Ancestor
Number of
Ancestors
1
2000
Self
1
2
1970
Parents
2
3
1940
Grandparents
4
4
1910
Great Grandparents
8
5
1880
2nd Great Grandparents
16
6
1850
3rd  Great Grandparents
32
7
1820
4th Great Grandparents
64
8
1790
5th Great Grandparents
128
9
1760
6th Great Grandparents
256
10
1730
7th Great Grandparents
512
11
1700
8th Great Grandparents
1,024
12
1670
9th Great Grandparents
2,048
13
1640
10th Great Grandparents
4,096
14
1610
11th Great Grandparents
8,192
15
1580
12th Great Grandparents
16,384
16
1550
13th Great Grandparents
32,768
17
1520
14th Great Grandparents
65,536
18
1490
15th Great Grandparents
131,072
19
1460
16th Great Grandparents
262,144
20
1430
17th Great Grandparents
524,288
21
1400
18th Great Grandparents
1,048,576
22
1370
19th Great Grandparents
2,097,152
23
1340
20th Great Grandparents
4,194,304
24
1310
21st Great Grandparents
8,388,608
25
1280
22nd Great Grandparents
16,777,216