Why do some people have no foreskin?

somewhat less then 20% of men in the world find that they have no foreskin or a greatly reduced amount of foreskin because it has been cut of usually while they are still very young and in a position where they can not resist having their genitals mutilated with an operation known as circumcision. This is done in the majority of cases for religious or cultural reasons. in some cases it is done for cosmetic reasons and in the USA and to a lesser extent in other English speaking countries for so called health reasons. In very rare cases people are born deformed in this department and have no foreskin.