Inbreeding - Inbred humans - Encyclopedia II

The royal families of Europe have close blood ties which are strengthened by intermarriage; the most discussed instances of interbreeding relate to European monarchies. Examples abound in every royal family; in particular, the ruling dynasties of Spain and Portugal were very inbred. Even in the British royal family, which is very moderate in comparison, there has scarcely been a monarch in 300 years who has not married a (near or distant) relative. Indeed, Queen Elizabeth II and her husband Prince Philip are second cousins once removed, both being descended from Christian IX of Denmark. They are also third cousins as great-great-grandchildren of Queen Victoria. Other examples include:

• Mary, Queen of Scots and Henry Stuart, Lord Darnley were half first cousins, and 3rd cousins once removed
• King William III and Queen Mary II were first cousins
• King George I and Princess Sophia Dorothea of Celle were paternal first cousins
• King George IV and Princess Caroline of Brunswick were first cousins
• Queen Victoria and Prince Albert of Saxe-Coburg-Gotha were first cousins
• King George V and Princess Mary of Teck were second cousins once removed
• The House of Habsburg intermarried famously
• Many Egyptian Pharaohs married their sisters

However, it is not necessarily the case that there is a greater amount of inbreeding within royalty than there is in the population as a whole: it is simply better documented. Among genetic populations that are isolated, opportunities for exogamy are reduced. Isolation may be geographical, leading to inbreeding among peasants in remote mountain valleys. Or isolation may be social, induced by the lack of appropriate partners, such as Protestant princesses for Protestant royal heirs. Since the late middle ages, it is the urban middle class that has had the widest opportunity for outbreeding.

Among the descendants of Mayer Amschel Rothschild, the founder of the famous financial and banking family, many of the men married their brothers' daughters or cousins related through the male line, neither of which practices is forbidden by Jewish law. They also had the tradition that only male descendants in the male line could participate in the business, though daughters did inherit considerable wealth. These two traditions were a means of keeping the business closely in the family. This was the reason that, in 1901, the Frankfurt branch of the family business was closed when the male line that managed it died out.

Adapted from the Wikipedia article "Inbred humans", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki/Main_Page