FIGURE 1.1 Taxa recognized in a typical speciose hominin taxonomy. Note that the height of the columns reflects either uncertainties about the temporal age of a taxon, or in cases where there are well-dated horizons at several sites, it reflects current evidence about the earliest (called the first appearance datum, or FAD) and the most recent (called the last appearance datum, or LAD) fossil evidence of any particular hominin taxon. However, the time between the FAD and the LAD is likely to represent the minimum time span of a taxon, because it is highly unlikely that the fossil record of a taxon, and particularly the relatively sparse fossil records of early hominin taxa, include the earliest and most recent fossil evidence of a taxon. The newest archaic hominin taxon, the ca. 1.9 Ma Australopithecus sediba, would occupy the space just above the box for Au. africanus.
Resolving the Branching Structure of the Higher Primate Part of the Tree of Life
The first systematic investigation of the relationships among the living great ape taxa was in 1863 by Thomas Henry Huxley. In the second of the three essays in his Evidence as to Man’s Place in Nature, Huxley addresses “the place which Man occupies in nature and of his relations to the universe of things” (1863, p. 57). After reviewing the evidence Huxley