I was attempting to explain this to people back in the 1970's when the Club of Rome was ranting about the population bomb. Even at the peak growth rate, birth rates by cohort and Total Fertility Rates were already declining. The global population reached the inflection point at about 3.5 Billion to 4 billion back in the middle 1970s.
While birth rates and Total Fertility Rates had been declining in the Muslim world for a generation, they imploded drastically since 2,000. The decline is so sudden and is occurring in so many Muslim countries (Afghanistan is the major exception) that one can not dismiss conspiracy theories about vaccines or GMO crops being covert contraceptives.
It is also possible that Muslim immigrants might assimilate to Western culture. A look at the yearbook for Cairo university shows Egyptian women dressing just like European women. The radicalism has been very sudden and might be short lived.
Finally, the solution along with immigration is to not devote your life to fornication rather than procreation.
Michael Everett wrote:I post the following purely for the reaction. I can neither confirm nor deny that I actually believe any of it.
There is a problem with attempting to extrapolate from past data. I think that this comic describes at least one of the potential pitfalls better than I could. How you extrapolate affects the end result more than what you extrapolate.
As for the whole "outbreeding" concept, gender differentials come into play. With the demand for male children that many cultures have, the ratio of male to female children (normally 105/100) becomes seriously skewed. Some cultures have a worse than 120/100 ratio. This sort of ratio seems to coincide with a rise in societal violence and the suppression of women's rights/liberties/protection (legal and physical). I do not know what/if the correlation is, or even if there is one. After all, it was once believed that thunder caused milk to go sour and they have no causative link whatsoever.
Another factor is that quite a few cultures practice inbreeding via cousin-marriage. It is a statistical anomaly that a certain culture (which I will not name) in the UK that is responsible for less than 3 percent of all births account for over 10 percent of all genetic birth defects. This is because in quite a few of the families, the parents of the newlyweds are cousins as well and the genetic distortion caused by such close relatives having children mounts up through the generations in the absence of new blood. Such an effect will cause more resources of the culture in question to be used in looking after their disabled portion, thus cutting down on the resources available for things like expansion.
Ironically, many of Europe's royal families practiced something similar in order to "preserve the purity of their blood". Since they knew the downsides of inbreeding in the horses they used, one can only speculate why they thought themselves above such trivial things as the laws of nature.
Sheesh.
Finally, if you are worried about other cultures outbreeding yours, just have more kids (preferably with an intelligent spouse as to raise the average IQ of the offspring)! It ain't rocket science!