I've been googling the subject for the past hour as well.
You'll find I am not averse to online research; it was not your numbers but your syntax I was unsure of, and it seemed more civil to ask than to research and assert.
It's a fascinating subject: your numbers hold up. The resistance could also partially explain the greater impact of HIV on the African-American community
It appears homozygosity of the allele confers nearly complete immunity, heterozygosity, greater resistance to both infection and progression; fortunately, neither appears to confer any deleterious effect.
The more recent study abstracts I've been able to view confirm the immunity/resistance, but question the bacterial/bubonic cause, hypothesizing instead a virus, perhaps a hemorrhagic fever like Ebola, or even smallpox.
From a 2007 popular account:
quote:
The source of that genetic pressure is still being debated by scientists. The early favorite was the Black Death, the Bubonic plague that swept through Europe in the Fourteenth century.
Other researchers have hypothesized that the period of selective pressure created by the Bubonic plague, roughly 400 years, was not
long enough for the overwhelming presence of the gene to appear.
These researchers suggest that smallpox, which has killed as many people as the plague over a much longer time period, could have provided sufficient selective pressure.
To support this conclusion, it is proposed that the continued presence of the mutated gene...is due to the fact that smallpox was only eradicated recently while the plague hasn't been a serious problem in 250 years. Indeed, a cousin of the smallpox virus has been shown to use CCR5 to enter host cells. Thus, CCR5-32 may provide resistance to smallpox.
Since I enjoy an apparent immunity to chickenpox and smallpox, perhaps survival of my wayward youth had more to do with lucky genes than anything else.
Have you ever been to an American wedding? Where's the vodka? Where's the marinated herring?!
-Gogol Bordello
Real things always push back.
-William James