first involved showing empirically that the albumins of several Old World Monkey (Cercopithecoidea) species was equally different from human albumin and chimpanzee albumin (within experimental error). This constituted a relative rate test of molecular change, and showed that both human and chimpanzee albumin lineages must have accumulated approximately equal amounts of change since their common ancestor (else one would be more different from the outgroup monkeys than the other), thereby providing direct empirical evidence of an approximate molecular clock for this molecule. This same pattern (i.e., equal distance between any two species and a more distantly related 'outgroup' species) held for all the empirical comparisons they made among primate species (within experimental error). Further work on additional molecules (for example, transferrin and hemoglobin) showed that these had also evolved in an approximate clocklike pattern in different Primate lineages. Phylogenetic trees based on these pattern of species differences were then constructed, though these could only indicate relative branch points, because the molecular differences - though having been shown by the relative rate test to have evolved approximately clocklike over millions of years - could not by themselves indicate how fast or slow the clock was (i.e., how many changes had occurred per unit of time). For this, Sarich and Wilson used the most well-established fossil evidence (In particular: no primates of modern aspect had been found prior to the K-T boundary, ~65 million years ago) to calibrate the tree's branch points. This work on a variety of molecules (and confirmed by modern DNA differences) consistently suggested a recent (~5 million year old) common ancestry with the African apes (chimpanzees and gorillas). Subsequent fossil discoveries, notably Lucy, and reinterpretation of older fossil materials, notably Ramapithecus, showed these younger estimates to be likely correct and have validated the pattern implied initially by Sarich and Wilson's albumin data. Empirical demonstrations that the molecular clock principle held among large groups of organisms (through application of the relative rate test) revolutionized the study of molecular evolution. Sarich's later work on race strengthened his reputation as a controversial figure. He applied his earlier work to racial differentiation, which he saw as subgroupings below the level of species. He also argued that the smaller the amount of time required to create a given number of morphological difference, the more selectively significant the differences would necessarily be. Sarich was a proponent of sociobiology, evolutionary psychology, and that racial differences