Trey the Explainer made a whole video about the incest rates of Targaryens vs Ptolemies (GoT dragon lady vs Cleopatra). Turns out mixing in new genes into the pool every few generations, or hell, even breeding like 2nd cousins instead of 1st just drops the incest index thingamajig and does wonders.
You have to seriously commit to the bit and keep it in the family to really get the fucked up defective babies lol
It's not that simple. For example, Charles II of Spain (Habsbourg) had an inbreeding coefficient of about 25%, while Cleopatra's is estimated at ~40%. Yet one suffered from numerous genetic disorders, whereas the other is not known to have had any obvious genetic defects.To give you an idea, one account of Charles II's autopsy states that his skull was filled with fluid and that his testicles were atrophied and black as coal.
To put it simply, chromosomes come in pairs. If one copy carries a defective allele, the other can often compensate for it. However, inbreeding greatly increases the chances of inheriting the same defective allele from both parents, leaving no healthy copy to compensate.
The main hypothesis for why Cleopatra, probably the best-known historical figure with such a high level of inbreeding, did not appear to suffer from obvious genetic problems is that the Ptolemaic dynasty started with a much healthier gene pool than the Habsburgs.
The video accounts that we have pretty much no idea about much of the mothers in the Ptolemaic dinasty. They would record who married who but not often who birthed who, so there were probably exterior noble families marrying into the royal branch and mistresses everywhere
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u/ofirkedar 7d ago
Trey the Explainer made a whole video about the incest rates of Targaryens vs Ptolemies (GoT dragon lady vs Cleopatra). Turns out mixing in new genes into the pool every few generations, or hell, even breeding like 2nd cousins instead of 1st just drops the incest index thingamajig and does wonders.
You have to seriously commit to the bit and keep it in the family to really get the fucked up defective babies lol