Did too much inbreeding end the Spanish Habsburg line?

[Syt]

In a general ORLY? moment:

The Role of Inbreeding in the Extinction of a European Royal Dynasty

Abstract Top

The kings of the Spanish Habsburg dynasty (1516–1700) frequently married close relatives in such a way that uncle-niece, first cousins and other consanguineous unions were prevalent in that dynasty. In the historical literature, it has been suggested that inbreeding was a major cause responsible for the extinction of the dynasty when the king Charles II, physically and mentally disabled, died in 1700 and no children were born from his two marriages, but this hypothesis has not been examined from a genetic perspective. In this article, this hypothesis is checked by computing the inbreeding coefficient (F) of the Spanish Habsburg kings from an extended pedigree up to 16 generations in depth and involving more than 3,000 individuals. The inbreeding coefficient of the Spanish Habsburg kings increased strongly along generations from 0.025 for king Philip I, the founder of the dynasty, to 0.254 for Charles II and several members of the dynasty had inbreeding coefficients higher than 0.20. In addition to inbreeding due to unions between close relatives, ancestral inbreeding from multiple remote ancestors makes a substantial contribution to the inbreeding coefficient of most kings. A statistically significant inbreeding depression for survival to 10 years is detected in the progenies of the Spanish Habsburg kings. The results indicate that inbreeding at the level of first cousin (F = 0.0625) exerted an adverse effect on survival of 17.8%±12.3. It is speculated that the simultaneous occurrence in Charles II (F = 0.254) of two different genetic disorders: combined pituitary hormone deficiency and distal renal tubular acidosis, determined by recessive alleles at two unlinked loci, could explain most of the complex clinical profile of this king, including his impotence/infertility which in last instance led to the extinction of the dynasty.

(continues at link site)



Doesn't come close to the Ptolemaians, though.

[Razgovory]

So it's not good when your family tree is all zig-zaggy like that huh?

[Drakken]

Thank you very much, Captain Obvious.

The real question should be: Why did the Austrians Habsburgs survive until 1918?

[Valmy]

So basically the Spanish and German branches just kept marrying each other.

Oddly the German branch did not seem to have the genetic problems the Spanish one did despite that fact.  Maybe they just lost the genetic lottery with Charles II.

[garbon]

Btw, that family tree diagram is horrible.

[Drakken]

So basically the Spanish and German branches just kept marrying each other.

Was such a developed study really needed on something that was, well, obvious to anyone remotely knowledgeable about the Habsburgs?

[Valmy]

Was such a developed study really needed on something that was, well, obvious to anyone remotely knowledgeable about the Habsburgs?

It might be interesting to track who had what genetic disorder and how they got passed on...but yeah it is no mystery that the Habsburgs did not marry outside the main line much.

[PDH]

Btw, that family tree diagram is horrible.

They get an "F" in my Intro to Anthropology class.

[garbon]

They get an "F" in my Intro to Anthropology class.

There are much clearer ways of showing marriages and descendants.

[Syt]

Was such a developed study really needed on something that was, well, obvious to anyone remotely knowledgeable about the Habsburgs?

It might be interesting to track who had what genetic disorder and how they got passed on...but yeah it is no mystery that the Habsburgs did not marry outside the main line much.

"When you reduce the family tree to a family bush you can't hide so much under it!"

[PDH]

There are much clearer ways of showing marriages and descendants.

Indeed - there is a reason that the standard system has lasted so long...it works well.

[Drakken]

There are much clearer ways of showing marriages and descendants.

Indeed - there is a reason that the standard system has lasted so long...it works well.

The problem with the standard system is that it isn't adapted to the fact that the Habsburgs were relentlessly incesting from uncle to niece or between first-degree cousins.

[Syt]

Since this is a genetic hereditary study of the Habsburg I guess they chose depiction in line with that field, not genealogy.

[garbon]

Except that, that system at least shows an x between parents.  There is no x in this system.

[Martinus]

Thank you very much, Captain Obvious.

The real question should be: Why did the Austrians Habsburgs survive until 1918?

Tremere blood.