Hominid evolution and the eventual rise of modern humans is thought to be a rather vague science by many unfamiliar with the field. The public at large (that is, those that have never taken a physical anthropology class) would not be able to recognize the hominids Australopithecus bahr el grazel, or even Australopithecus habilus. It is however, likely that they would be able to recall the well-publicized Lucy (or Australopithecus afarensis to the paleoanthropologically savvy). For the everyday Joe, human evolution begins with A. afarensis, passes through Homo neanderthalensis and ends with us (which is quite clearly incorrect). Indeed, A. afarensis had been, prior to 1994, the sole root of our family tree as a species (Culotta, 1995: 918). However, this all changed when in 1994, and then 1995, remains of hominid species older than A. afarensis were found (1995: 918).
Ardipithecus ramidus discovered in 1994 by Tim White and crew, and then Austrolapithecus anamensis in 1995 by Meave Leake and crew, are the earliest pieces to the puzzle of hominid evolution (Smithsonian Institution, 2000). The problem then, is figuring out how these pieces fit in with the rest of the puzzle. A. anamensis's features closely resemble those of the apes, however a number of derived traits suggest relation to later australopithecines (Boyd, Silk, 2000: 340). Thus, A. anamensis may or may not be the ancestor of A. afarensis, but certainly shares some common ancestor with it (Leake et al, 1995: 568). A quick look at the phylogenetic tree shows us that if we are to accept the connection between A. anamensis and A. afarensis, and then from A. afarensis to all other
later hominids, all hominids have commonality with A. anamensis (Smithsonian Institution 2000). Alan Walker, who was a member of the party responsible for the tremendous discovery remarks that the phylogenetic tree may be better described as a bush. This comes as a response to the findings near the beginning of hominid evolution, where evidence suggests that there are multiple candidates for the true ancestor to later australopithecines (Sawyer, 1995: A1)
Leake et al worked hard at dating the A. anamensis fossils correctly. The testing processes involved the examination of Kanapoi sediment, and the relation of the A. anamensis fossils in relation to the remains of other vertebrate remains in the area. By finding the remains of other vertebrates alive at that time, Leake and her team were able to place A. anamensis in relation to the eras of the surrounding vertibrates. Their findings place A. anamensis from 3.9 to 4.1 million years ago (Leake et al, 1995: 570-571). This time range places this species after A. ramidus, but before A. afarensis and all later australopithecines. (Hotz, 2001) To quote Leake and her team: "Isotope dating confirms A. anamensis' intermediate age as being between...