Why do some people who are unrelated look so alike (ie celeb look alikes)?

Question

People always tell me that i look like another girl who lives local. Ive never met her, but d**n she must be pretty.

Answer 1

People say i luk lyk janet jackson n i sure knw we ard most def nt related.

Answer 2

there are probably 4-5 archetypes of the human race.