Posted on 02/02/2016 1:35:32 PM PST by jmaroneps37
I am completing my family tree which goes back 39 generations on one branch and 14 on another. I would like to explain to my grandchildren how unique the DNA combination they have is. We have roots to a canonized saint in our bloodline as well as an American Revolutionary War solider and a famous Irish revolutionary hero too. I just need to show the children how small the odds are of duplicating our family tree. Anyone that can help please Freepmail me, Thanks much
I am sorry to break this news to you, but your DNA is no more and no less unique than the DNA of every other human being alive.
In other words about 1 in 30,000,000,000,000,000,000,000,000,000,000,000,000.
That's 1 out of 3x10 to the 37th power.
This is about 2x10 to the 19th power more than the entire number of human beings who have ever lived. We're all equally unique.
Cindy Crawford and Bill Hader can trace their roots all the way back to Charlemagne
The odds are zero. There are no two non-siblings with the same family tree. See, that was easy.
However, even siblings get a different mixture of chromosomes from their common parents.
Each parent (usually) contributes half of each of their 23 chrom. pairs.
That makes each combination one out of 2 to the 23rd power, squared.
Because of the simple math of losing half of the genome each generation, and the odd number of chrom. pairs, we don’t share any DNA with most of our ancestors — but they are still our ancestors, because they had to do the wild thing in and pass down half their DNA in order for the chain to even exist.
Each of us has (usually) 64 great-great-great-great-g-parents; there are (usually) 32 on each side of the family; that makes it obvious that 9 on each side passed down no chromosomes whatsoever to you personally — they may have passed each of their 46 to *someone* as long as they had more than one child, but it would have (at best) survived in one your collateral lines.
Have fun!
http://www.freerepublic.com/tag/genealogy/index
Best laugh I've had all day ... thanks!
400-500 years is typical, but unusual to find that in each and every one of ones lines (the fam' here has one set going back to the late 15th century; another just stops dead circa 1800). The handful of people with ancestors from Iceland may be able to get back at least a couple of centuries more. What is basically NOT possible is any reliable information whatsoever, apart from the alleged noble pedigrees (and they crawled all over each other like a box of hamsters, so what the surviving docs say and the reality are going to be at least two different things), before the 10th century. Too bad, because I'd make the wild guess that a number of horndogs from history, like Mark Anthony, probably have millions of descendants, and most of them in common with one another.
Probability of what? Or maybe you mean how permutations exist (when order is important) for the family tree to get this large? Or probability that the grand kids were born? 100%
Back that far, we're ALL related.
Everybody does. They’re the only ones they have been able to survive and reproduce.
The hard part is finding them.
Actually, the further back you can prove your ancestry, the higher the probability that you’re related to everybody else who can do the same. I’ve got all of mine back to their colonial era arrivals with the exception of a few who were natives. If you have proven Jamestown ancestry, you’ve got a whole lot of cousins in the southeast. My direct paternal line has been difficult to get past his 1660 arrival in St. Mary’s City, Maryland, despite having records of the ship, knowing where it launched and having a surname that is as English as the day is long. He wasn’t transported, so he wasn’t an indentured servant. Best candidate in England I can find for him was orphaned in the very last plague outbreak. If that’s him, I can go further back to the 13th century if not before, some minor nobility there and that means good records were kept.
My family lost some nice swords, spears, and bows in the same boating catastrophe.
She is diligent and has been working on this stuff for years.
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