Why do we look different? If we look at elephants, they have distinct features, but they aren’t unique like humans. We have so many genes that affect our appearance, and this heterogeneity evolved because identifying one another is crucial. How else would I know my Mum? Or the person who did me a favour? Or the person who killed my friend? There are other means; some animals use olfactory cues, while others rely on proximity assuming those around are friendly. However, humans almost entirely use looks.

It’s appropriate to distinguish between two types of unique phenotypic traits. The first is identity cues that differ between people but do not confer a survival advantage by being used for differentiation. Fingerprints or teeth are examples.
Identity signals facilitate individual recognition and assist in animal survival. In humans, facial traits show more variability than other body parts. Facial features are genetically independent, meaning that each aspect is combinable with another. For example, blue eyes don’t necessitate blonde hair meaning more configurations are possible.