Why do people who aren't related can look eerily similar?

Question

Why do people who aren't related, can look eerily similar to other people around the world? Does it all come down to our lineage?

Answer 1

People connected by common lineage are genetically related and very well might share similar facial features.

However, looks are determined by the shape of skull, muscle structure, fatty and cartilage tissue layers, skin textures and other features which can also be very similar for people who have no direct link.

Chromosomal inheritance is marked by a limited number of possible phenotypes for each trait relating to the human face (which is the area most used to differentiate looks).  Some people have a remarkable number of similar phenotypes even if they are totally unrelated by genetic inheritance.

Answer 2

Because we are all the same species, and variations are limited...