Final answer:
Social Darwinism was a misinterpretation of Darwin's theory that some people applied to modern human societies to justify social class distinctions and racism. However, this interpretation was discredited and does not align with Darwin's original scientific discoveries.
Step-by-step explanation:
Social Darwinism, a misinterpretation of Darwin's theory, was applied to modern human societies by some individuals in the 19th and 20th centuries. It suggested that societal success and power were determined by superior breeding and those who were deemed weaker should perish. This theory was used to justify social class distinctions and racism. However, it is important to note that this interpretation of Darwin's theory was discredited and does not align with his original scientific discoveries.