When did racism "begin"?

by brentonator

What time period did racism begin to develop in society? I feel in ancient periods slavery and discrimination was more cultural/economic but obviously racism has developed into a large issue everywhere in the world. When did this start? Can it be attributed to any one person or train of thought/theory?

slightly_offtopic

Not to discourage further discussion, but there are several threads on the topic of racism in the FAQ. I'd like to draw your attention particularly to this excellent treatise by u/victoryfanfare