In the opinion of some, basic types of organisms have hybridized in the past, and certain modern races of men have resulted from a man-beast cross. A review of pertinent literature shows that it abounds with unreliable reports on the crossing of plants and of animals. With regard to man, modern anthropologists and geneticists agree in the opinion that human beings have never crossed with any animal. Genetically the morphological differences between two basic types of organisms result from their different DNA'S. The pattern of the nucleotides in the hereditary material determines the basic type of the organism. In order to hybridize, individuals must have the same general DNA pattern. All relevant laboratory data indicate that if the general DNA patterns are different, then a chemical incompatibility exists between these basic types which makes true fertilization, and resultantly hybridization, impossible. In the light of modern findings, the fact that, according to Genesis 1 and 2, all basic types existing on the earth have been present since creation week, guarantees to Bible believers that every basic type of organism, including the human type, is 100% pure type in all its generations.