what are the origins of this prejudice?
Evolutionary psychologists John Tooby and Leda Cosmides reasoned that natural selection would not have favoured the evolution of an instinct for using race as a classification, because for most of human history, humans almost never encountered members of other races.
Racism
Evolutionary psychologists John Tooby and Leda Cosmides were puzzled by the fact that in the US, race is one of the three characteristics most often used in brief descriptions of individuals (the others are age and sex). They reasoned that natural selection would not have favoured the evolution of an instinct for using race as a classification, because for most of human history, humans almost never encountered members of other races. 
who propounded the nebular hypothesis for the origin of the earth Immanuel Kant what does this hypothesis state? It suggests that the Solar System formed from gas and dust orbiting the Sun. what are the different types of planets formed out of it? Moon, Mars who is the person mentioned above? A German philosopher and one of the central Enlightenment thinkers. has he authored any books? Yes - Critique of Pure Reason, Allgemeine Naturgeschichte und Theorie des Himmels where was he from? Born in  Königsberg, East Prussia. what were his views on race-related issues? He promoted racism. He wrote that "[Whites] contain all the impulses of nature in affects and passions, all talents, all dispositions to culture and civilization and can as readily obey as govern. They are the only ones who always advance to perfection.”
wiki:25597289
Racism [SEP] Theories about the origins of racism
Evolutionary psychologists John Tooby and Leda Cosmides were puzzled by the fact that in the US, race is one of the three characteristics most often used in brief descriptions of individuals (the others are age and sex). They reasoned that natural selection would not have favoured the evolution of an instinct for using race as a classification, because for most of human history, humans almost never encountered members of other races. Tooby and Cosmides hypothesized that modern people use race as a proxy (rough-and-ready indicator) for coalition membership, since a better-than-random guess about "which side" another person is on will be helpful if one does not actually know in advance.