marriage practices. In this sense, his attempts to statistically demonstrate universal principles of kin relation s resembled White's effort to formulate a universal theory of cultural evolution. (McGee and Warms, 1996) Besides, William C. Boyd also suggests that there is no doubt that some rectilinearity can often be observed in evolution. Nevertheless, rectilinear evolution is far from universal. (Boyd, 1952) Another key issue concerning human evolution is the issue of race. The definition of race, according to many anthropologists, is based on the frequency of certain genes. William C. Boyd defines race as that "A race is not an individual, and it is not a single genotype, but it is a group of individuals more or less from the same geographical area (a population), usually with a number of identical genes, but in which many different types may occur." His definition or race is a genetic one. (Boyd, 1952) Echoing Boyd, Dobzhansky also suggests that races arise chiefly as a result of the ordering of the genetic variability by natural selection in conformity with the environmental conditions in different territories. He said that "since human population often, in fact usually, differ in the frequencies of one or more, usually several to many, genetic variables, they are by this test racially distinct." (Dobzhansky, 1962) However, this definition of race is not favored by some other anthropologists. For example, Frank B. Livingstone even rejected the concept of race. He pointed out that although it is true that there is biological variability between the populations of organisms which comprises a species, this variability does not conform to the discrete packages labeled races. In other words, there are no races, the are only clines. He suggested that the variability in the frequency of any gene does not utilize the concept of race. (Livingstone, 1962) Sherwood L. Washburn defines race as a group of genetically similar populations. He a...
