Hogwarts, & the Magic World (was:... students ARE there at Hogwartz?)

[sigurd at eclipse.net]

No: HPFGUIDX 191577

Dear Liz and Dorothy

One point. As we all know from examples here in the US,if inbreeding is adopted as a preferred CHOICE then it doesn't take too long. Just a few generations is necessary to produce critical birth defects, hereditary disease, hemophilia, downs syndrome not to mention general physical malaise. That's entirely a different thing from a given community  running out of options for exogamy. Witness the Amih in America, after two hundred years in small inward drawing communities how have a problem with birth defects, dwarves, and some very serious hereditary disease.

Put in more basic terms, it's one thing to go to family reunions looking to pick up women for girlfriends, its another when  a few dozedn families become so intermixed its impossible to avoid close intermarriage.

Now... OBVIOUSLY the human race has been a closed system for oh-- 60,000 years or so, but from the standpoint of the whole race intermarriages have taken place but the human race has not run out of persons to inject other genetic patterns into a given community. But it does not seem that you even need a community that large to guard against excessive inbreeding. Genetic variation seem to occurr naturally with a population of just over 10,000 such that it will never be too intermarried. That is, new genetic variation is produced spontaneously even in generally linked communities. The question is how large does a community have to be to avoid this or practice forced exogamy.

This is admittedly one of those droll technical points that can suck the life out the magic of Potter et all, but I suspect that the figure is around that 10,000 mark.

Just a grim little thought.

Otto