Hmmmmmmmm......................
This type of story regularly crops up.
"The odds are virtually 100 percent", - Aye, that'll be right
The logic goes like this......... King XXXXX and Queen YYYYYYY had 6 children who all married and they all had children, and so on and on, across all the generations to the present day, and it doesn't take too many generations before the resultant number of descendants is into the miillions.
There's two flaws in this logic, which I'm going to leave TS members to tease out.
But I will leave you with the following thoughts. On the basis of the above logic, any of the early Stuart kings (who married and had a number of children, - both legitimate and illegitimate!) should have a number of descendants approaching the present population of Scotland of 5m, - not impossible, of course, given the Scottish diaspora.
But there were maybe 999,998 other people in Scotland at that era, i.e. the population was somewhere around 1 million. Let's say that 50,000 of that 1m were married couples, then the same logic
should apply to all those couples (well nearly all, aprart from those who were childless). On that basis it doesn't take too long with a calculator to work out that the present population of the whole world must be descended from Scots ........
And that's without taking into account anyone living furth of Auld Scotia in the last few centuries.
So who's going to bell the cat

, and work out the reasons why the original logic is incorrect. Of the two main reasons, the one is the reason why there aren't anything even beginning to approach the numbers of royal and other descendents that this logic
demands that there are.
Good luck to Brook Shileds, and if she chooses to believe that tree, then good luck to her.
BTW, I've always wondered where I got these high cheekbones from along with my "Mongolian eyes"

k

[see
http://sunzi1.lib.hku.hk/hkjo/view/27/2700175.pdf ]
David