Relatedness Part 1
All of my ancestors had two biological parents. They may not have been married, the births may have been illegitimate, and the fathers identities may sometimes never be known, but they definitely had 2 parents.
This will change with cloning, but it still holds true today with my ancestors and I.
I will estimate that each of my ancestors generations spans 25 years. That is, the average age of the parent was 25 when their child who was my ancestor was born. That may be slightly too low of an estimate, but it will make the math of 4 generations per century much easier.
I had 512 individuals who were my 7th Great Grandparents. I have found the names and birth dates of 9 of them. I will demonstrate how close their average birth year is to 1725 later.
Therefore, I should have the following number of ancestors in each generation:
| Generation | Number of Ancestors | Approximate Birth Year | Their Offspring Are My | World Population Estimates | |
| Me | 1950 | ||||
| 1 | Parents | 2 | 1925 | Siblings | |
| 2 | Grandparents | 4 | 1900 | 1st cousins | |
| 3 | Great Grandparents | 8 | 1875 | 2nd cousins | |
| 4 | 2nd Great Grandparents | 16 | 1850 | 3rd cousins | |
| 5 | 3rd Great Grandparents | 32 | 1825 | 4th cousins | |
| 6 | 4th Great Grandparents | 64 | 1800 | 5th cousins | |
| 7 | 5th Great Grandparents | 128 | 1775 | 6th cousins | |
| 8 | 6th Great Grandparents | 256 | 1750 | 7th cousins | |
| 9 | 7th Great Grandparents | 512 | 1725 | 8th cousins | |
| 10 | 8th Great Grandparents | 1,024 | 1700 | 9th cousins | |
| 11 | 9th Great Grandparents | 2,048 | 1675 | 10th cousins | |
| 12 | 10th Great Grandparents | 4,096 | 1650 | 11th cousins | |
| 13 | 11th Great Grandparents | 8,192 | 1625 | 12th cousins | |
| 14 | 12th Great Grandparents | 16,384 | 1600 | 13th cousins | |
| 15 | 13th Great Grandparents | 32,768 | 1575 | 14th cousins | |
| 16 | 14th Great Grandparents | 65,536 | 1550 | 15th cousins | |
| 17 | 15th Great Grandparents | 131,072 | 1525 | 16th cousins | |
| f18 | 16th Great Grandparents | 262,144 | 1500 | 17th cousins | |
| 19 | 17th Great Grandparents | 524,288 | 1475 | 18th cousins | |
| 20 | 18th Great Grandparents | 1,048,576 | 1450 | 19th cousins | |
| 21 | 19th Great Grandparents | 2,097,152 | 1425 | 20th cousins | |
| 22 | 20th Great Grandparents | 4,194,304 | 1400 | 21st cousins | |
| 23 | 21st Great Grandparents | 8,388,608 | 1375 | 22nd cousins | |
| 24 | 22nd Great Grandparents | 16,777,216 | 1350 | 23rd cousins | |
| 25 | 23rd Great Grandparents | 33,554,432 | 1325 | 24th cousins | |
| 26 | 24th Great Grandparents | 67,108,864 | 1300 | 25th cousins | 423,000,000 |
| 27 | 25th Great Grandparents | 134,217,728 | 1275 | 26th cousins | |
| 28 | 26th Great Grandparents | 268,435,456 | 1250 | 27th cousins | |
| 29 | 27th Great Grandparents | 536,870,912 | 1225 | 28th cousins | |
| 30 | 28th Great Grandparents | 1,073,741,824 | 1200 | 29th cousins | 400,000,000 |
| 31 | 29th Great Grandparents | 2,147,483,648 | 1175 | 30th cousins | |
| 32 | 30th Great Grandparents | 4,294,967,296 | 1150 | 31st cousins | |
| 33 | 31st Great Grandparents | 8,589,934,592 | 1125 | 32nd cousins | |
| 34 | 32nd Great Grandparents | 17,179,869,184 | 1100 | 33rd cousins | 320,000,000 |
| 35 | 33rd Great Grandparents | 34,359,738,368 | 1075 | 34th cousins |
This shows that my number of ancestors would exceed the world population between 1200 AD and 1300 AD.
Would it be reasonable to assume that everyone should be my 29th cousin or closer from this?
Probably not, because the above numbers do not take into account the relatedness of each pair of ancestors. That is, to what degree do cousins marry their cousins?