"Hereditary hemochromatosis?" General Wang was slightly taken aback.
"In simple terms, hereditary hemochromatosis is the buildup of iron in the body. It has to be treated through bloodletting," Song He explained.
"The rate of hereditary hemochromatosis gene carriers isn't high anywhere in the world. There's only one exception: Northern and Western Europe. As many as one in four people there carry the gene, and the incidence is significantly higher than in other regions."
"Why is it so high?" General Wang asked with a frown.
"The Black Death."
"The Black Death?"
"Yes. The infamous Black Death in European history had both high transmissibility and a high mortality rate. During the first wave alone, it quickly wiped out half of Europe's population. So many people died in such a short time that there weren't enough people to bury the bodies, and they piled up like mountains. Rats fed on the corpses and reproduced like crazy, while swarms of rats and the disease-carrying fleas on them swept across Europe. The Europeans at the time thought the end of the world had arrived. For them, it really wasn't much different."
"It's a universally known part of history. I remember it lasted roughly three hundred years." General Wang nodded. "What exactly does it have to do with hereditary hemochromatosis?"
"People with hereditary hemochromatosis were more likely to survive after contracting the Black Death." Song He pointed out the key.
General Wang suddenly understood. "It's a bit like quenching thirst with poison—a temporary cure for one disease in the form of another?"
"Exactly. Back then, people with hereditary hemochromatosis could only live to forty, but those who contracted the Black Death, regardless of age, could only survive for three to five days. So forty became a ripe old age, giving them the chance to reproduce. After