The term often leads into confusion, however, since international compact cars are somewhat larger than their North American equivalents, mostly because no supermini/subcompact size is manufactured by American, Mexican and Canadian car makers up to date.
By the late 1860's, Darwin came to describe this process as the survival of the fittest. This is very different from Lamarck's incorrect idea that the environment altered the shape of individuals and that these acquired changes were then inherited.
Spencer is best known for the expression  survival of the fittest , which he coined in Principles of Biology (1864), after reading Charles Darwin 's On the Origin of Species.