Unilineal evolution (also referred to as classical social evolution) is a 19th-century social theory about the evolution of societies and cultures. 

It was composed of many competing theories by various sociologists and anthropologists, who believed that Western (European) culture is the contemporary pinnacle of social evolution (the theory of white supremecy). 

This western theory teaches that; different social status is aligned in a single line that moves from most primitive to most civilized, (the most primitive state of life, being the stage where man looked more like a monkey with black features, dwelling in caves, as man became more civilized, his features also became more white, western or European). 

Theories of social and cultural evolution are common in modern European thought. Ancient Greece and Ancient Rome produced levels of technical accomplishment which Europeans of the Middle Ages sought to emulate. 

At the same time, Christianity (the Roman version of Jesus), taught that; people lived 
in a debased (primitive) world fundamentally before the age of Greek and Rome, inferior (lower in value) to the Garden of Eden and Heaven. 

During the Age of Enlightenment, however, European self-confidence grew and the notion of progress became increasingly popular. It was during this period that what would later become known as ‘sociological and cultural western evolution’ would have its roots.

The western Evolution began to hide all the ancient text revealing ancient civilization, and through the western conjured information done via the culmination of history’s progress, civilization was attributed to the beginning of Europe (Greek and Roman Empire).

This theory is now generally considered obsolete in academic circles.