Forbidden Archeology: The Hidden History of the Human Race

The OH 62 find supports our suggestion that the ER 1481 and ER 1472 femurs from Koobi Fora, described as very much like those of modern Homo sapiens (Section 11.6.3), might have belonged to anatomically modern humans living in Africa during the Late Pliocene. These femurs have been attributed by some workers to Homo habilis and by others to Homo erectus. But these attributions are questionable. Showing this will, however, take a few paragraphs of unavoidably obscure and intricate analysis of bone morphology.

In his book Lucy’s Child (Johanson and Shreeve 1989, photo section), D. Johanson suggested that the comparatively large ER 1481 femur was the Homo habilis male counterpart to the smaller OH 62 female Homo habilis femur.

But the attribution of the ER 1481 femur to the same species as OH 62 involves a

Figure 11.10. (Traced from Johanson and Shreeve 1989, photo section.) According to D. Johanson, the KNM-ER 1481 femur from Koobi Fora, Kenya, is from a male Homo habilis. It is, however, much larger than the OH 62 female Homo habilis femur from Olduvai Gorge. Attributing both femurs to the same species implies an unusual degree of sexual dimorphism. They display a greater size difference than the male (AL 333-3) and female (AL 288) Australopithecus afarensis femurs from Hadar, Ethiopia. Some workers have said that the degree of sexual dimorphism in the Hadar sample is too great to be accommodated within a single species. The same may be true of the KNM-ER 1481 and OH 62 femurs.

remarkable degree of sexual dimorphism for Homo habilis. The ER 1481 femur is much bigger than the OH 62 female femur (Figure 11.10).

Johanson believed, however, that the femurs of Lucy (AL 288) and a male hominid (AL 333-3) from the Hadar, Ethiopia, site displayed a degree of sexual dimorphism similar to that of the OH 62 and ER 1481 femurs. This made it conceivable, to Johanson, that the OH 62 and ER 1481 femurs might belong to a single species of hominid. To us, however, the degree of sexual dimorphism in OH 62 and ER 1481 appears much greater than that in the Hadar femurs.

Furthermore, although Johanson thought that both Hadar femurs belonged to one species (Australopithecus afarensis), other paleoanthropologists have said that the AL 333-3 femur, along with many other fossils attributed by Johanson to Australopithecus afarensis, actually belonged to Homo individuals (Groves 1989, pp. 260–263).

One of these workers (Zihlman 1985, pp. 216–217) demonstrated that putting all the Hadar hominids in one species would involve sexual dimorphism more extreme than that encountered in the most sexually dimorphic anthropoid apes (Section 11.9.8). Zihlman therefore believed Johanson was not justified in assigning all the Hadar fossils to a single species.

If the Hadar fossils were too sexually dimorphic to be included in one species, we believe the same would be true of the ER 1481 and OH 62 femurs, which seem to manifest an even greater degree of sexual dimorphism than the Hadar femurs.

Johanson’s attribution of the ER 1481 and OH 62 femurs to a single species appears to be a consequence of his belief that only one hominid species other than Australopithecus boisei (namely, Homo habilis) existed around 2 million years ago in East Africa ( Willis 1989, p. 263).

As we shall see in Section 11.7.5, some workers have suggested that Homo habilis represents at least two species, including, perhaps, an australopithecine. Wood (1987), for example, proposed that small, apelike OH 62 might represent an East African gracile australopithecine rather than Homo habilis.

Accepting this, one might try to keep the traditional picture of Homo habilis. One could then, as previously, attribute the ER 1481 and ER 1472 femurs to Homo habilis, as represented by the somewhat humanlike ER 1470 skull. But the ER 1481 and ER 1472 femurs were found some distance from the ER 1470 skull, which means there is no solid reason to connect them. Attribution of the ER 1481 and ER 1472 femurs to Homo habilis is therefore questionable.