From wikipedia :
Not thousands, I’m sure, but still probably several. And even if William and his descendants were having children only at replacement rate, that’d still give you an average of 1 son per generation, and if anyone can be expected to have children at greater than replacement rate, it’d be a king.
Except only 1 of his descendants at a time is king. Most eventually fade into obscurity, like you and me (likely as not to be descendants).
At any rate, the two situations are not even close to being comparable.
William I - no known illegitimate children. Illegitimate himself he may have personal reasons to avoid having them. Four legitimate sons, five daughters.
Robert Curthose - eldest son of William. One legitimate son, two known bastards.
Richard - second son of William, died in twenties unmarried. No known descendants, but who knows - he was certainly old enough to produce some before he died.
William II Rufus - died unmarried. Highly likely was at least bisexual ( apparently not uncommon situationally among the younger Norman nobility ). No known descendants, but again at such a remove anything is possible.
Henry I - unrepentant horndog. Two legitimate children, at best guess ~35 bastards. If you’re looking for ground zero for Norman royal genes, he’s your best bet ;).
Why don’t we all just cal him great-great…great granddad and call it day!
While it’s unlikely that she shares genes, it is likely that she shares breaths.
Statistics and probability theory are pretty awesome.
While I applaud you for taking the time to do actual math, I do wonder about treating things on the single gene level.
In my highschool biology, discussing Mitosis and Meiosis, the whole DNA-strand always coiled up into the chromosomes, and those were then divided (more or less by chance) so that each egg/ sperm has half of the parents chromosomes.
Each chromosome is a coiled DNA-strand with thousands of genes on them. So wouldn’t a person inherit whole chromosome from their dad or nothing, not a single gene? (True, that would be difficult to follow - Do we even have a full known family tree from William to Elizabeth?)
Which is a great question. Is ERII even a known direct descendant of WtC?
I was considering going through the painful process of trying to trace it out, but apparently these days there is a wiki for almost everything ;).
That also clears up the number of generations: 25. Much less than we would think if we assumed 1 generation = 25 years, giving us 40 generations. Although we are assuming 1,000 years, too, which is slightly off. Still, longer average generation than typical, but it makes sense since the male line is favored and there were intervening uncles in there as well.
Here is an interesting discussion about how likely that someone is you cousin.
You’re forgetting about recombination, which means chromosomes are inherited as more or less random chunks rather than as a whole. Over several generations, Person X’s chromosomes will be taken apart and mixed up with other chromosomes to the point that you really can’t say that that chromosome exists. Tracking at the gene level is more realistic at this sort of time scale, but even individual genes can be recombined and go through the same process.
But you only need one many-progeny generation (like Henry I’s children) to insulate the line from the sorts of statistical fluctuations that could wipe it out. Once you have that, it’s fine for all the rest of the descendants to be be perfectly ordinary in their reproductive proclivities.
There is no one from 1000 years ago who is an ancestor of all living people today. To get there you’d have to go back before the first Homo Sapiens left Africa. Map of Human Migrations
There are groups in New Zealand, for instance which have never been genetically mixed. There are groups in Brasil which haven’t even been contacted. It’s just ridiculous. It completely ignores geographic separation.
Just because they’ve never mixed directly with Westerners doesn’t mean there’s no gene flow. The “isolated” tribe will still have some contact with their neighbors, including interbreeding, and those neighbors will have contact with their neighbors, and so on.
We’ve been over this in many other threads. The identical ancestor point is 5k - 15k years ago. That is the point where everyone alive is either the ancestor of no one or the ancestor of everyone alive today. The Most Recent Common Ancestor lived 2k - 5k years ago.
There are no populations in New Zealand that have not mixed. And it doesn’t matter if some group in Brazil was not contacted. They mated with villages that have been contacted. 500 years is a long, long time.
Well, I don’t know how many progeny are needed to “insulate” the line, and we only have a guess at the number of children H I had, but we’re wandering into the realm of speculation, so I’m going to let it drop.
There doesn’t even need to be gene flow. All that’s really needed is for one conquistador’s great^6 grandchild to be a common ancestor to that isolated tribe. It’s not implausible for that theoretical person (who would, in all likelihood, be completely genetically indistinguishable from any other South American native) to be a common ancestor to even the most remote tribe, and that tribe would all be descended from Europeans. And they may not have a single one of his genes today.
Are there any decent hypotheses about where humanity’s MRCA may have lived? I ask because John Mace linked to a Wiki article that quotes, “we share ancestors who planted rice on the banks of the Yangtze, who first domesticated horses on the steppes of the Ukraine, who hunted giant sloths in the forests of North and South America, and who labored to build the Great Pyramid of Khufu.” I frankly doubt the possibility that everyone alive today has an ancestor who lived in North America 10,000 years ago, because I don’t know of any post-land-bridge contact with the Old World until the Vikings, and even 1000 years seems too short for a large amount of intermixing with the populations of the entire world. I’m trying to imagine a scenario where the Vikings brought a Beothuk to Iceland, whose descendants made it back to Norway, then through Eurasia, and ended up among the Sentinelese, and it’s just not working.
I’m confused. Isn’t the operative number 46 for the number of chromosomes and not the number of genes? So after 7 generations there is 46/128 < 0.5 chance they share a common chromosome?
I wondered if I should mention recombination (where parts of the chromosome break off and are combined differently), but my impression was that it was rare and not part of the normal Mitosis/ meiosis process.
Is it in fact common enough to be assumed for every generation? Are some people more likely for it? Is it a factor of the age of parents when they reproduce?