In the third revision of Genetics and the Origin of Species (1951), Dobzhansky rewrote all ten chapters on: Isolating Mechanisms, Mutation in Populations, Organic Diversity, Heredity and Mutation, Race Formation, Selection, Adaptive Polymorphism, Hybrid Sterility, Species as Natural Units, and Patterns of Evolution. Dobzhansky decided to remove the chapter on Polyploidy in the third edition. The new chapter on Adaptive Polymorphism highlighted Dobzhansky’s research since the second edition. He included precise, quantitative evidence on effective natural selection in laboratory and free populations. Debate about race Theodosius Dobzhansky and Ashley Montagu debated the use and validity of the term "race" over a period of many years without reaching an agreement. Montagu argued that "race" was so laden with toxic associations that it was a word best eliminated from science completely. Dobzhansky argued that science should not give in to the misuses to which it had been subjected, and that the concept of animal and plant races has been important in biology; the modern synthesis used the concept for describing the diverging biological populations differing in gene frequencies. This was done in hopes that its foundation in population genetics would undermine the deeply ingrained social prejudices associated with "race". His concern with the interface between humans and biology may have come from different factors. The main factor would be the race prejudice that contributed in Europe that triggered WWII. His concern also dealt with religion in human life which he speaks about in his book The Biology of Ultimate Concern in 1967. "The pervasiveness of genetic variation provides the biological foundation of human individuality". Dobzhansky talks about in great detail that "human nature has 2 dimensions: the biological, which mankind shares with the rest of life, and the cultural, which is exclusive to humans." Both of these are believed to have come from "biological evolution and cultural evolution". Dobzhansky sought to put an end to the pseudoscience that purports genetic makeup to determine race, and thus rank in society. Harrison E. Salisbury wrote in a New York Times review of Dobzhansky's book Heredity and the Future of Man that Dobzhansky could not, together with other scientists, agree upon what defines a race. Dobzhansky stated that a true bloodline for man could not be identified. He did not believe that a person's genetic makeup decided whether or not he would be a great man but rather that man "has the rare opportunity 'to