Darwin did not believe or argue there were five races of man. ILA/DY, as usual, is playing the part of lying scumbag.
http://en.wikipedia.org/wiki/Historical_race_concepts#Charles_Darwin_and_Race
By the late 1860s, however, Darwin’s theory of evolution had been thought to be compatible with the polygenist thesis (Stepan 1982). Darwin thus used Descent of Man to disprove the polygenist thesis and end the debate between polygeny and monogeny once and for all. Darwin also used it to disprove other hypotheses about racial difference that had persisted since the time of ancient Greece, for example, that differences in skin color and body constitution occurred because of differences of geography and climate.
Darwin concluded, for example, that the biological similarities between the different races were “too great” for the polygenist thesis to be plausible. He also used the idea of races to argue for the continuity between humans and animals, noting that it would be highly implausible that man should, by mere accident acquire characteristics shared by many apes.
Darwin sought to demonstrate that the physical characteristics that were being used to define race for centuries (i.e. skin color and facial features) were superficial and had no utility for survival. Because, according to Darwin, any characteristic that did not have survival value could not have been naturally selected, he devised another hypothesis for the development and persistence of these characteristics. The mechanism Darwin developed is known as sexual selection.
Though the idea of sexual selection had appeared in earlier works by Darwin, it was not until the late 1860s when it received full consideration (Stepan 1982). Furthermore, it was not until 1914 that sexual selection received serious consideration as a racial theory by naturalist thinkers.
Darwin defined sexual selection as the “struggle between individuals of one sex, generally the males, for the possession of the other sex”. Sexual selection consisted of two types for Darwin: 1.) The physical struggle for a mate, and 2.) The preference for some color or another, typically by females of a given species. Darwin asserted that the differing human races (insofar as race was conceived phenotypically) had arbitrary standards of ideal beauty, and that these standards reflected important physical characteristics sought in mates.
Broadly speaking, Darwin’s attitudes of what race was and how it developed in the human species are attributable to two assertions, 1.)That all human beings, regardless of race share a single, common ancestor and 2.) Phenotypic racial differences are superficially selected, and have no survival value. Given these two beliefs, some believe Darwin to have established monogenism as the dominant paradigm for racial ancestry, and to have defeated the scientific racism practiced by Morton, Knott, Agassiz et. Al, as well as notions that there existed a natural racial hierarchy that reflected inborn differences and measures of value between the different human races. Nevertheless he stated: : “The various races, when carefully compared and measured, differ much from each other - as in the texture of hair, the relative proportions of all parts of the body, the capacity of the lungs, the form and capacity of the skull, and even the convolutions of the brain. But it would be an endless task to specify the numerous points of difference. The races differ also in constitution, in acclimatization and in liability to certain diseases. Their mental characteristics are likewise very distinct; chiefly as it would appear in their emotion, but partly in their intellectual faculties” (The Descent of Man, chapter VII).