The First Humans: Origin and Early Evolution of the Genus Homo (Vertebrate Paleobiology and Paleoanthropology)
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There are some issues in human paleontology that seem to be timeless. Most deal with the origin and early evolution of our own genus – something about which we should care. Some of these issues pertain to taxonomy and systematics. How many species of Homo were there in the Pliocene and Pleistocene? How do we identify the earliest members the genus Homo? If there is more than one Plio-Pleistocene species, how do they relate to one another, and where and when did they evolve? Other issues relate to questions about body size, proportions and the functional adaptations of the locomotor skeleton. When did the human postcranial “Bauplan” evolve, and for what reasons? What behaviors (and what behavioral limitations) can be inferred from the postcranial bones that have been attributed to Homo habilis and Homo erectus? Still other issues relate to growth, development and life history strategies, and the biological and archeological evidence for diet and behavior in early Homo. It is often argued that dietary change played an important role in the origin and early evolution of our genus, with stone tools opening up scavenging and hunting opportunities that would have added meat protein to the diet of Homo. Still other issues relate to the environmental and climatic context in which this genus evolved.
another H. erectus individual, S7–37 from Sangiran, Java, are examples of where such evidence has been useful in reconstructing dental development in H. erectus. Histological analysis of S7–37 allowed Dean et al. (2001) to cross-match the internal microstructure of the developing M1 with the developing Pm4, even though the specimen was adult. Combining information from all these specimens is gradually allowing us to build a chronology of tooth formation and eruption for the species. A preliminary
Caucasus. Nature 373, 509–512. Grine, F.E., 1986. Dental evidence for dietary differences in Australopithecus and Paranthropus: a quantitative analysis of permanent molar microwear. Journal of Human Evolution 15, 783–822. Grine, F.E., 2005. Early Homo at Swartkrans, South Africa: a review of the evidence and an evaluation of recently proposed morphs. South African Journal of Science 101, 43–52. Grine, F.E., Ungar, P.S., Teaford, M.F., 2002. Error rates in dental microwear quantification using
which to compute the estimated total endocranial capacity of OH 7. By the end of 1963 the first result was obtained. I was amazed at its high value, 675–680 cm3. At that time, the mean capacity for A. africanus was 504 cm3, though later studies by Holloway cropped this average to 441–442 cm3. The mean for Homo erectus at that stage was 974 cm3. Thus, the estimated value for OH 7 lay between the means for A. africanus and H. erectus. The OH 7 value also lay between the highest value in the A.
paradigm of the early 1960s. Just as the “prematurity” of Dart’s (1925) Australopithecus africanus lasted a quarter of a century before being overcome, that of Homo habilis took about 15 years before the species gained wide acceptance. Tobias dates the turning of the tide to its recognition by F. Clark Howell (1978) in his compendious chapter in the Evolution of African Mammals. He notes that a consensus then seemingly developed that H. habilis was a “good species,” but that two other proposals
al., 2003). Although the evidence for such a distinction has not been accepted by all workers (e.g., Suwa et al., 1996; Miller, 1991, 2000; Dunsworth and Walker, 2002; Lee and Wolpoff, 2005), including Tobias, the number of Homo species represented by the Early Pleistocene fossils in East Africa remains very much an open issue (Baab, 2008). The second proposal to which Tobias alludes addresses the nature of the genus itself. In Chapter 3, Bernard Wood asks whether the fossils attributed to Homo