C

new specimen to a species via the only material preserved — its anatomy. Curnoe and Thorne do not look at the fossil record at all; they say what the species ought to be, not what they actually are according to a detailed analysis of the evidence.

Their version of H. africanus would include the five species currently allocated to Australopithecus (one of which of course is A. africanus, specimen A in Figure 1.7) and the three species allocated to Paranthropus (one of which is P. boisei, specimen B in Figure 1.7). As such, this single species would include one "sub-population," defined by a high frontal (forehead), well-developed snout (similar to that observed in living chimpanzees), with a relatively narrow and gracile facial structure, undeveloped bony ridges along its braincase associated with reduced musculature, large front teeth, small back teeth, and relatively thin molar enamel; and another subpopulation with the exact opposite condition, totally lacking a forehead, a flat face lacking a snout, a broad and heavily built facial structure, massive bony ridges along its braincase for strong musculature attachments, extremely small front teeth, massive back teeth, and hyperthick molar enamel. Clearly these "subpopulations" are defined by a number of differing evolutionary adaptive trends (see Chapter 5). We would not expect to see such distinct trajectories within one species. In terms of adaptive trends, a number of patterns are present, again refuting the idea that these taxa represent one species. Let us also emphasize this most strongly: No living ape species, or monkey species for that matter, even comes close to such extremes in anatomical variability. It makes the large degree of anatomical variability observed in gorillas (male and females combined!) look tiny by comparison.

Indeed, if Curnoe and Thorne were to try and produce a description of their species H. africanus, we believe that the degree of anatomical variability expressed would swallow up the anatomical condition present within at least two of their four other species, namely H. ramidus and H. habilis, and possibly H. troglodytes as well. Homo sapiens would probably be the only species to survive this pruning and remain a distinct species. There would now be just two species, H. africanus and H. sapiens. It is also not unimportant that what most people today would call Australopithecus africanus (specimen A in Figure 1.7) and Homo habilis (specimen C in Figure 1.7) are increasingly thought to be closely related. Indeed, some consider H. habilis to represent a species of Australopithecus — A. habilis (Wood & Richmond, 2000). Infact, it is surprising that Curnoe and Thorne (2003) maintain the species distinction between africanus and habilis, which are overall very "similar," while at the same time lumping the very different species within Paranthropus and Australopithecus into just one species, H. africanus.

Let us remind ourselves that paleontologists who have conducted "blind" studies on samples of skeletal remains of living primates tell us that we are liable in almost all cases to vastly underestimate the number of species present in any given sample; the exact opposite of what the Multi-regionalists would have us believe (Cope, 1988, 1993; Cope & Lacy, 1992; Plavcan, 1993; Shea et al., 1993; see also other papers in Kimbel & Martin, 1993). This is to say that skeletal remains appear to underrepresent actual speciation: Variation is more prolific than skeletal or fossil anatomical variability. For example, Figure 1.8 presents a principal component

REGR factor score 2 for analysis 1

Figure 1.8 ► Principal components analysis of extant Pan paniscus and Pan troglodytes specimens as well as fossil hominins.

Extant Pan data is from Cameron (unpublished raw data), while fossil hominin data is from B.A. Wood (1991) (see text for details).

REGR factor score 2 for analysis 1

Figure 1.8 ► Principal components analysis of extant Pan paniscus and Pan troglodytes specimens as well as fossil hominins.

Extant Pan data is from Cameron (unpublished raw data), while fossil hominin data is from B.A. Wood (1991) (see text for details).

analysis (metric characters) of Pan paniscus and Pan troglodytes specimens as well as fossil hominins. It can be seen that under the "revised multiregionalist" definition, Homo africanus (shaded area) is almost twice as great in range as the combined range of the two species of Pan. The molecular clocks tell us that this combined range of variability represents around 2.5 million years of evolution (i.e., the two species of Pan split around 2.5 million years ago). The time depth of the revised H. africanus represents just half of this (the range from oldest to youngest specimens is around 1 to 1.5 million years), though the specimens have twice the range of variability. Clearly at least two species of hominin are represented within the "revised Multiregionalist" Homo africanus.

Again, non-metric variability is vastly greater between extant and fossil hominid groups than between the two chimpanzee species. Table 1.1 presents a breakdown on phenotypic characters (non-metric anatomical features) used by Cameron (in press [b], submitted) in his analysis of fossil hominin systematics. The first is based on an analysis of 72 characters, the second uses 92 characters. While we stress that these values are crude "yardsticks" and alone cannot be used to determine taxonomic allocations, they clearly support the idea that a number of species (even, in

TABLE 1.1 ► Phenotypic Differences Between Taxa

Specific Percentage: Based on 72 phenotypic characters

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