ABSTRACT
The ancestors of modern humans probably lost their connection with the rest of the animal kingdom between about five and eight million years ago. There is now abundant evidence that the animals most closely related to modern humans are the two living African apes-that is, the chimpanzee (Pan) and the gorilla (Gorilla). Because both of these ape genera are non-human in their behaviour and superficial appearance, it was naturally assumed that they were more closely related to each other than either was to modern humans. However, when the proteins and the genomes are compared, there is evidence that some of the DNA in both the nucleus and the mitochondria of the cells of Homo sapiens and Pan are very similar in structure. Indeed, the DNA of Pan is apparently more similar to that of Homo than it is to Gorilla. While an increasing number of researchers are convinced that the similarities between Homo and Pan are significant, some of their colleagues remain sceptical and suggest that the details of the close relationships between Homo, Pan and Gorilla presently cannot be resolved. If, however, we accept the overwhelming evidence for a close relationship between modern humans and the African apes, how is that African ape/modern human group related to the rest of the animal kingdom?
