19 research outputs found
The functional significance of dental and mandibular reduction in Homo: A catarrhine perspective.
The reduction in dental size and mandibular robusticity is regarded as a major trend in human evolution, traditionally considered the result of the peculiar extra-oral food processing skills of Homo. The use of stone tools and fire would have allowed our ancestors to chew softer food in smaller bite size, thus relaxing the selective pressures to keep a large dentition and a robust lower jaw. This perspective assumes that differences in dental size and mandibular robusticity in hominins represent functional dissimilarities. This study uses a catarrhine comparative approach to test this fundamental assumption of the hypotheses on dental and mandibular reduction in Homo. A sample of extant catarrhines and fossil hominins was used to test for correlations between dental size, mandibular robusticity, and dietary proxies, the latter include diet quality, diet heterogeneity, feeding time, and microwear variables. The effects of phylogeny and body size were considered. Findings support the association between technological developments in Homo and reduction in incisor size and mandibular corpus robusticity, though not for premolar, molar size, and symphyseal robusticity. These results challenge the functional interpretation of postcanine reduction and symphyseal changes in the genus Homo
The âmosaic habitatâ concept in human evolution: past and present
The habitats preferred by hominins and other species are an important theme in palaeoanthropology, and the âmosaic habitatâ (also referred to as habitat heterogeneity) has been a central concept in this regard for the last four decades. Here we explore the development of this concept â loosely defined as a range of different habitat types, such as woodlands, riverine forest and savannah within a limited spatial areaâ in studies of human evolution in the last sixty years or so. We outline the key developments that took place before and around the time when the term âmosaicâ came to wider palaeoanthropological attention. To achieve this we used an analysis of the published literature, a study of illustrations of hominin evolution from 1925 onwards and an email survey of senior researchers in palaeoanthropology and related fields. We found that the term mosaic starts to be applied in palaeoanthropological thinking during the 1970âs due to the work of a number of researchers, including Karl Butzer and Glynn Isaac , with the earliest usage we have found of âmosaicâ in specific reference to hominin habitats being by Adriaan Kortlandt (1972). While we observe a steady increase in the numbers of publications reporting mosaic palaeohabitats, in keeping with the growing interest and specialisation in various methods of palaeoenvironmental reconstruction, we also note that there is a lack of critical studies that define this habitat, or examine the temporal and spatial scales associated with it. The general consensus within the field is that the concept now requires more detailed definition and study to evaluate its role in human evolution
Modeling the Past: The Paleoethnological Evidence
This chapter considers the earliest Paleolithic, Oldowan (Mode 1), and Acheulean (Mode 2)
cultures of the Old Continent and the traces left by the earliest hominids since their departure
from Africa. According to the most recent archaeological data, they seem to have followed two
main dispersal routes across the Arabian Peninsula toward the Levant, to the north, and the Indian
subcontinent, to the east. According to recent discoveries at Dmanisi in the Caucasus, the first
Paleolithic settlement of Europe is dated to some 1.75 Myr ago, which indicates that the first âout of
Africaâ took place at least slightly before this date. The data available for Western Europe show
that the first Paleolithic sites can be attributed to the period slightly before 1.0 Myr ago. The first
well-defined âstructural remainsâ so far discovered in Europe are those of Isernia La Pineta in
Southern Italy, where a semicircular artificial platform made of stone boulders and animal bones
has been excavated. The first hand-thrown hunting weapons come from the site of Schošningen in
north Germany, where the first occurrence of wooden spears, more than 2 m long, has been
recorded from a site attributed to some 0.37 Myr ago. Slightly later began the regular control of
fire. Although most of the archaeological finds of these ages consist of chipped stone artifacts,
indications of art seem to be already present in the Acheulean of Africa and the Indian
subcontinent
Human Evolution and the Chimpanzee Referential Doctrine
Chimpanzees are our closest living genomic relatives, but they lack the bipedal locomotion, markedly enlarged brains, and advanced communication skills of humans. This has led many to view them as âprimitiveâ and to presume that their behavior and anatomy are also primitive. If true, they could serve as models of our last common ancestor (LCA), i.e., a territorially aggressive knuckle walker, reliant on vertical climbing and below-branch suspension to access the high canopy as a ripe-fruit frugivore. Ardipithecus now provides abundant information that the LCA differed substantially from chimpanzees (as well as bonobos and gorillas), both anatomically and behaviorally, and exhibited many characters that are more similar to those of modern humans than to any living ape. This major extension of the hominoid fossil record contravenes strict referential modeling based on the extant chimpanzee and greatly improves our ability to reconstruct the LCA more accurately, but only when viewed within the broader context of evolutionary ecology