Muslim men marry their eight year old first cousins who then start producing children at age eleven.
What could possibly go wrong such a Gene Pool?
Goggle “Muslim inbreeding”. In Pakistan the population is 70% the product of cousin-marriage. Inbreeding over fourteen centuries has produced hideous results.
Combine inbreeding with polygamy and the aforementioned “bachelor herd” becomes an inexhaustible source of jihad fodder.