Gene Expression  Well, it turns out that there isn’t a handy-
dandy reference for the numbers for various religions in the
past. Mark Kirkorian over at The Corner linked to my earlier
post where I expressed skepticism about the contention by the
Vatican demographer that a larger number of Muslims than Roman
Catholics is new. Other people have contacted me as well. In any
case, my hunch is that in fact Muslims were more numerous than
Roman Catholics in the period between 950 and 1750, though the
window could be shorter. My reasoning below the fold….  1) By
about 1000 most of the core Islamic lands had become majority
Muslim. That is, Iran and what would become the Arab speaking
world had fewer Christians, Jews and Zoroastrians than Muslims
for the first time since the original Islamic conquest. It seems
likely that Christianity was already extinct in the Maghreb by
1000 judging by the observations of Christian pilgrims, though
Islam was likely only near parity in the Levant and Egypt (even
today 10-20% of Arabs