Have we ever heard or read that there were lions and tigers roaming in London ? No..!!
Have we ever read or heard of apple growing in sahara desert ? NO..!!
The super natural power who created planet has designated different parts of it for different purpose/products/inhabitants.
Character like muhammed a two-legged desert beast came in deserts of arabia to preach and teach what is supposed to be taught to inhabitants/products/desert beasts of that part of planet and which strictly apply to those beasts only.
Unfortunately, because of some weaknesses caused by social evils in other civilised part of planet, these beasts went astray and polluted human races.
Those illegitimate breeds of those beasts spread in different parts of planet doing their work of looting,killing etc became inhabitants with passage of time.
Now modern and civilised world is at all not ready to accomodate these breeds.It is making these breeds to scream and more violent.These human look-alike beasts are aware that they are now an ENDANGERED SPECY as they have been made and taught to fight and kill each other and leave this planet for normal human races.