The Japanese Imperial Throne follows strict male line inheritance.
But
a) the Royal families keep having mostly girls and
b) they don’t bother having many kids.
0Mutsuhito (born 1852) is Japan’s analogue to Empress Sophia. He had four daughters and one son, Yoshihito.
1Yoshihito did have four sons as follows:
11Hirohito had five daughters and two sons.
His son 111Akihito is the current Emperor and has two sons and one daughter. Akihito’s son 1111Naruhito is in fact heir apparent to the throne. He married Masako and after eight years of married when Masako was 37, she gave birth to a girl, Aiko, and had no more children (she is now 52 and not likely to have more children.) This led to considerable controversy in Japan and consideration of the idea of changing the constitution to allow an Empress to rule or broaden the scope of the Royal family. Akihito’s other son 1112Fumihito looked to be heading the same way as he and his wife had had two daughters by the time she was 39, but when she was 40 years old she gave birth to a son 11121Hisahito who is now ten years old. This 11th hour birth is what forestalled constitutional change.
Hirohito’s other son, Masuhito, is still alive at 80 years old and has no children.
12Yasuhito had no children.
13Nubihito also had no children.
14Takahito is still alive at 100 years old, and has two daughters and three sons.
His eldest son 141Tomohito had two daughters, no sons.
His second son 142Yoshito had no children.
His third son 143Norihito had three daughters, no sons.
This is quite a remarkable outcome, that after FIVE generations a dynasty has only one male-line heir likely to continue the line, and even that was a close run thing. You’d think that people in a dynasty with this kind of inheritance would just keep fucking until they had sons galore, but all the lines are clogged by people with no children or people with daughters only.
The British monarch has of course operated on male-*preference* inheritance wherein you will resort to female monarchs if there are no sons (but this has recently changed to a gender neutral form), and the key ancestor (Electress Sophia) was born in 1630, so there are thousands of potential heir-producers now (including my lady love Karin Vogel).
But by comparison, after five generations Sophia had produced a shit-ton of heirs even if we restrict it to male-line descent.
It makes one reflect on how precarious Y-DNA descent is and why the haplogroups winnow so rapidly. Of the people alive today, only a few hundred will have male line descendants alive a thousand years hence.
