That's just an example.
Genealogy has been very serendipitous. I need to know French to make sense of some of the records; I took French starting in 7th grade (mostly to bolster an excuse for not taking PE). I need to know Dutch to make sense of some of the records; I've been working on learning Dutch for several years on my own, primarily in support of a couple trips I took to visit family in the Netherlands.
Occasionally, I get handed sheets that are the-way-genealogists-organized-informati
So we can add to the list of useful things to know about before attempting genealogy: data structures. Handy, that comp sci degree.
Part of why I was pursuing the 50th cousin thing (other than my grandmother's parents-are-first-cousins thing and pedigree collapse) was because I've been trying to visualize the larger human family tree. The 50th cousin argument isn't the _most_ foolish argument (that would be exponential growth _without_ accounting for pedigree collapse), but it's not that far removed, either. Call it a second cousin.
Here's what we all agree on about the human family tree: with the possible exception of the immediate past, it gets smaller as we go backwards in time (that is, there were fewer people alive Way Back When). If I look at my tree (all lines of ancestry, not just patri- or matri-lineal), it gets bushy, and then it shrinks down again. The questions lie in the nature of the bushiness in the middle. We know that, due to geography (that is, oceans, and the difficulty or at times impossibility of crossing them), some parts of the human family tree were isolated from one another. We know that, due to human culture (reproductive rules enforced by cultural groups), some parts of the human family tree are/were isolated from one another. MRCA, 50th cousinhood, etc. is an effort to get "above" that: to what degree are we _not_ isolated from one another.
I don't think that's interesting. I'm too young to have really _internalized_ any kind of belief system that I'm not related to everyone else out there (and while I hesitate to make any definitive comment about the existence or nature of divinity, I'm prepared to assert we are also related to every other living thing). I'm not of the generation that erases difference to show respect and love and equality. I'm of the generation that feels like aggressively ignoring difference is colonizing. Here's what I think the tree looks like:
It is lumpy. It is a directed, acyclic (you can't be your own grandpa) graph. It is weakly connected internally. It is self-similar at all levels. That is, isolation occurs of small groups (people marry fellow villagers), medium-sized groups (or that they meet at the county fair), and large groups (or someone who was posted in their village as part of the army). It's not a bowl of nuts, or even lumpy oatmeal, because each "lump" is made up of another graph itself made up of weakly connected smaller lumps.
I could write a simulation to express this -- you could take Rohde et als and if you make the 5 parameters all a lot weaker than they were prepared to believe in, _and_ you made a sim a family instead of an individual, _and_ you made migration dependent upon a group decision -- if you did all those things, you wouldn't be far off from what I believe is true. I believe this is true because I find people utterly incomprehensible most of the time, so in order to make any sense at all out of them I have to laboriously find patterns and then test them exhaustively to figure out their limitations. And _this_ is what people do. When I say "high school" and "automobiles" changed the way we mate, I say that because "high schools" became the new "village" for mating purposes (and has since been replaced successively by colleges/workplaces and, honestly, lately, probably the internet). But none of that changed our "lumpiness" when it came to picking people to make babies with.
I think our "lumpiness" has a lot of good effects and a few bad ones. I think for one thing, the universality of our lumpiness (and how lumps "fission" to produce related lumps) are worthy of study. I think ignoring reality is never a good idea and an especially bad one in this particular instance. And I feel _very_ strongly about this.