AAPA 73rd Annual Meeting Abstracts: Search Results
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A multivariate apportionment of global diversity in contemporary humans based on craniometric traits. Palm DE: Saturday afternoon - April 26, 2003, 4:15-4:30 C.C. Roseman, T.D. Weaver. Dept. of Anthropological Sciences, Stanford University. Human Biology III: Reproduction/Demography/Variation Presentation type: podium Talk number: 14 The apportionment of diversity within and between human populations based on classical genetic markers and molecular polymorphism has shown that the majority of diversity is found between individuals within local populations. Previous assessments of quantitative genetic variation based on Howell's (1973) craniometric data set result in estimates of within and between population diversity that are similar to genetic data, suggesting a limited role for selection in producing human cranial diversity. However, these analyses were conducted on a pooled set of measurements and therefore included information about size, shape, and random error. Additionally, all variables were treated as a single large metavariable without assessing intercorrelations between variables. To address these issues, we convert the original measurements in Howells' data set into Mosimann shape variables and size (geometric mean of the original measurements) and extract principal components that serve as new independent variables. Few reliable principal components could be extracted. The first two principal components principally discriminate between populations. Subsequent components discriminate poorly between populations. Estimates of Fst based on the first two principal components are larger than previous estimates based on phenotypic variance pooled across all variables, suggesting that at least some differences in contemporary human cranial shape may be the product of interregionally differing selection. The limited number of reliably extractable principal components has implications for assessing the biological affinities of ancient samples.
A new brain volume for the Sts 60 specimen of Australopithecus africanus from Sterkfontein, S. Africa. Palm ABC: Saturday morning - April 26, 2003, 10:45-11:00 M.S. Yuan1, R.L. Holloway2. 1School of Dental and Oral Surgery & Dept. of Anatomy and Cell Biology, Columbia University, 2Dept. of Anthropology, Columbia University. Hominid Evolution VII: Miocene and Pliocene Evolution Presentation type: podium Talk number: 12 Since the claim by Falk et al. (2000) that some of the australopithecine brain endocast volumes were inflated, we have undertaken a full re-study of australopithecine endocasts to ascertain their most probable volumes. Here, we report that one of the natural endocasts, Sts 60, appears to have a volume of roughly 400 ml rather than the earlier estimates of 428 ml by Holloway (1970, 1973) or 435 ml by Tobias (1971).
Sts 60, an undistorted natural endocast, has an almost complete morphology on the left side, except for portions of the occipital pole, posterior cerebellar lobe, temporal pole, frontal bec, and distal brain stem with the foramen magnum. The right side retains most of the frontal lobe and a portion of the medial part of the parietal lobe. Holloway's original reconstruction was done by completing the missing portions with plasticene on the left side, and measuring the volume of the hemi-endocast by water displacement technique. In this study, a full endocast reconstruction of Sts 60 was performed. It provided a lower estimate at roughly 400 ml, a reduction of 7% in volume from the original determination. We are uncertain what has caused this discrepancy, although we suspect that midline placement was the most likely culprit.
We do not believe that other australopithecine volumes are inflated, such as Sts 71 and SK 1585, as reported earlier. We suggest that these differing volumes justify continuing efforts by independent researchers to find the most accurate assessment of these hominids' cranial capacities.
A new hominin calvaria from Ileret (Kenya). Palm ABC: Saturday afternoon - April 26, 2003, 1:45-2:00 M. G. Leakey1, F. Spoor2, F.H. Brown3, P.N. Gathogo3, L.N. Leakey1. 1Dept of Palaeontology, National Museums of Kenya, 2Dept. of Anatomy & Developmental Biology, University College London, 3Dept of Geology & Geophysics, University of Utah. Hominid Evolution VIII: Early Hominid Evolution Presentation type: podium Talk number: 4 In 2000 the Turkana Basin Research Project of the National Museums of Kenya resumed field work at sites in the Koobi Fora Formation, east of Lake Turkana. New hominin discoveries from Ileret include a well preserved calvaria KNM-ER 42700. The specimen was found in situ, almost fully embedded in a matrix of coarse sandstone and carbonates. Consequently, it attained nearly no damage due to postdepositional erosion, and extensive preparation has now resulted in one of the best preserved hominin cranial fossils from the east Turkana region. The specimen derives from strata 1.5-2 m below a tuff which is compositionally very similar to a tuff in the Koobi Fora Tuff Complex in Area 103, so the age is most likely between 1.5 and 1.6 Ma.
The calvaria is complete, with the exception of a small area of the vault around bregma. The frontal is slightly dislocated. The spheno-occipital synchondrosis is mostly fused suggesting that it concerns a subadult or young adult. Its overall vault shape, and characters such as frontal and parietal midline keeling are most similar to those seen in Homo erectus. However, the specimen differs from calvaria traditionally assigned to this species, by a significantly smaller size, and by the absence of both prominent supraorbital tori and supratoral hollowing. It shares these characteristics with the D2700 specimen from Dmanisi (Vekua et al. Science 297, 85-89, 2002). The morphology of KNM-ER 42700 will be described and comparisons will be made with the African and Asian Plio-Pleistocene hominin fossils.
A new hominin skull from Hadar: Implications for cranial sexual dimorphism in Australopithecus afarensis. Palm ABC: Saturday afternoon - April 26, 2003, 1:30-1:45 W Kimbel1,2, Y. Rak3, D. Johanson1. 1Institute of Human Origins, Arizona State University, 2Dept. of Anthropology, Arizona State University, 3Dept. of Anatomy, Tel Aviv University. Hominid Evolution VIII: Early Hominid Evolution Presentation type: podium Talk number: 3 In 2000 a fragmentary but well preserved adult hominin skull was recovered from the lower Kada Hadar member (~3.1 mya) of the Hadar Formation at Hadar, Ethiopia. The specimen, A.L. 822-1, includes a virtually complete mandible plus much of the calvaria, maxilla, zygomatics, and most upper and lower teeth. Distortion and breakage necessitated considerable reconstruction, the preliminary results of which are described.
We assign the skull to A. afarensis based on apparent autapomorphies in the supraorbital, zygomatic, and nasal regions. It also evinces the prevailingly primitive suite of characters known in A. afarensis specimens such as the A.L. 417-1 and A.L. 444-2 skulls and the A.L. 333 material. Dentally, A.L. 822-1 is moderately large (in 8/20 postcanine metric comparisons it exceeds Hadar means), but the small maxillary canine crown points to female status. This is supported by delicate zygomatic arches, thin supraorbitals, and the absence of sagittal and compound temporal/nuchal crests. Mandibular and maxillofacial size closely shadows that of A.L. 417-1, diagnosed as female by canine size.
A new human skeleton from the Middle Palaeolithic Peristeri I Cave, Epirus Greece. Campanile: Saturday morning - April 26, 2003, 8:30-12:00 A. Bartsiokas. Dept. of History & Ethnology, Democritus University of Thrace, Greece. Hominid Evolution VI: Pleistocene Evolution Presentation type: poster We report here on a new and relatively complete human skeleton of a child from the site of Peristeri I Cave, Kouklesi village, Epirus, Greece - a steeply dipping cave 67m deep. The specimen was recovered from the deepest part of the cave (39o 21' 55" and 20o51'06") in an isolated chamber named Lower Cave in which Middle Palaeolithic stone artifacts and charcoal have been found in excavations that started since 1995 by the author. Lower Cave was used as a place for stone knapping and contains only Palaeolithic finds. No associated artifacts were found with the skeleton so the chronological age of the skeleton is still unknown until any radiometric methods are employed. Parts of the skull, pelvis, teeth and long bones have been found so far. The epiphyses of the long bones are unfused. The skeleton was found completely covered by speleothem in a natural stalagmitic pit in a side wall of the cave in August 2002. The bones, though not articulated in an anatomical position, they were all closely packed together in the confined space of the pit. No rodent activity has been discerned so far that could have mingled the bones. Alternatively, gravity might have some effect in mingling the bones. Various hypotheses are still examined as to whether it was a deliberate bone or carcass disposal or a secondary interment. The excavation proceeded with a hammer drill and a chisel. The exposed bones were solidified in situ when necessary and protected with bandages before extraction of the stalagmitic blocks took place. Cleaning is taking place in the lab.
A new morphometric approach to inferring diet from hominoid incisors and canines using Analytical Comparison of Digitized Curvatures (ACDC). Campanile: Friday morning - April 25, 2003, 8:30-12:00 A.S. Deane1, E.P. Kremer2, D.R. Begun1. 1Dept. of Anthropology, University of Toronto, 2Dept. of Chemical Engineering and Applied Chemistry, University of Toronto. Primate Evolution III: Dental Development and Variation Presentation type: poster Diet is certainly one of the most basic ecological parameters defining a species. A particular dietary strategy is, in many cases, a primary ecological determinant for a variety of behavioural, demographic and social adaptations. Although field studies identify the complex dietary strategies of extant hominoids, traditional methods of dietary inference relying on dentition (dental wear, gross morphology, enamel micro-structure, molar shearing-crest length) often fail to reflect the true dietary complexity of apes. Conversely, Smith's (1999) analysis of hominoid molar cusp proportions ably demonstrates that a detailed morphometric approach to dietary inference is capable of an intrinsic degree of dietary resolution consistent with the known feeding behaviours of apes.
This study addresses the potential for detailed dietary inference based on morphometric analysis of incisor and canine crown curvatures. While traditional curvature indices are calculated from manual measurements, this study serves as a demonstration of a new computer assisted method for calculating curvature from 2-D digitized images. This methodology is a significant improvement over traditional methods that are limited by the assumption that curvature is symmetrical. ACDC makes possible a more thorough interpretation and analysis of the 'true curvature' and reduces the potential for measurement error.
Data was collected from dental samples representing all species and sub-species of the extant hominoidea, and a maximum of 23 measurements were recorded per individual. The results confirm that diet is the overriding selection mechanism for anterior dental morphology, and that more frugivorous taxa differ from more folivorous taxa in a number of key curvature indices.
A new technique for reconstructing the vocal anatomy of fossil humans. Palm ABC: Saturday afternoon - April 26, 2003, 4:00-4:15 S.F. Miller1, T.R. Yokley2, S.E. Churchill2, R.G. Franciscus1, J.J. Hublin3, K.L. Eaves-Johnson1. 1Dept. of Anthropology, University of Iowa, 2Dept. of Biological Anthropology & Anatomy, Duke University, 3Laboratoire d'Anthropologie, Université Bordeaux. Hominid Evolution VIII: Early Hominid Evolution Presentation type: podium Talk number: 13 Previous reconstructions of fossil human vocal tract (VT) anatomy have primarily been based on single skeletal indicators such as basicranial flexion or hyoid morphology. These studies have produced conflicting results. A few reconstructions have used combinations of indicators to predict VT morphology, but these have employed relatively subjective methods. In an attempt to better understand fossil human VT anatomy, we developed a new predictive technique that uses relationships between VT landmarks and associated skeletal landmarks of living humans as the basis for reconstruction. We believe that the use of these landmarks is more likely to produce reliable results than any single indicator, and that our method of analyzing relationships between skeletal and soft-tissue anatomy is less subjective than previous techniques. Using the software package C2000cépha v.2.1.B, we collected two large sets of landmark data from a sample of human clinical CT scans provided by the Clinique Pasteur in Toulouse, France. The first consisted of skeletal landmarks located on the basicranium, vertebral column, dentition, mandible, nasopharynx, nasal cavity, and nasal aperture. The second consisted of soft-tissue landmarks located along the VT. Through the combined use of generalized procrustes analysis, principal component analysis, and multiple regression, we derived multiple formulae that allow us to predict the position of soft-tissue VT landmarks based on associated skeletal landmarks. Preliminary work indicates that this technique facilitates a working 3-D approximation of the supralaryngeal VT from skeletal landmarks, and that it holds promise for the reconstruction of VT soft-tissue anatomy in Neandertal and other fossil specimens.
A phylogenetic approach to quantifying the relationship between age of first reproduction and maximum lifespan. Colonnade: Saturday afternoon - April 26, 2003, 1:30-5:00 G.E. Blomquist, M.M. Kowalewski, S.R. Leigh. Dept. of Anthropology, University of Illinois. Primate Biology V: Ontogeny, Hormones, and Life History Presentation type: poster Recent models of human life history evolution imply correlated evolution among a variety of reproductive and survivorship variables. However, questions remain about the strength of structural relationships among these variables. Moreover, relatively few analyses have applied rigorous phylogenetic controls to this problem. This study explores the patterns of correlations among life history variables in order to evaluate mechanisms that influence specific human life history attributes.
Data are derived from literature sources, and include age at maturation (alpha), lifespan estimates, and body mass for anthropoid primates. Regression analyses and partial correlations are applied to these data to assess structural relations among variables and provide scaling information. Phylogenetic control is undertaken using independent contrasts. Nine clades within the anthropoid sample are defined, six of which are nonoverlapping. Partial correlations with phylogenetically unadjusted data show no significant associations between alpha and maximum lifespan in anthropoids. Contrasts, however, indicate that alpha and maximum lifespan are moderately correlated (r=.720, p<.001). Adjusted data scale near isometry (m=.934 +/- .179).
These results provide evidence for correlated evolution between alpha and maximum lifespan. However, the strength of these correlations creates problems in interpreting specific cases and implies there is substantial room for divergent adaptive histories between these two traits. This may suggest that long delays in human maturation are not necessarily offset by compensatory changes in lifespan. Other life history, demographic, or cultural variables may play significant roles in structuring human life histories.
A pilot study of Y chromosome analysis on Melanesian populations. Palm DE: Thursday afternoon - April 24, 2003, 2:30-2:45 L. Scheinfeldt1,2, J. Lorenz2, R. Robledo2, A. Merriwether3, G. Koki4, C. Mgone4, J. Friedlaender1. 1Dept. of Anthropology, Temple University, 2The Coriell Institute for Medical Research, Camden, NJ, 3Dept. of Anthropology, University of Michigan, 4Institute for Medical Research, Goroka, EHP, Papua New Guinea. Skeletal Biology II: Diet and Biomechanics Presentation type: podium Talk number: 7 Recent and past anthropological literature shows Island Melanesia to be an area of extreme cultural and biological heterogeneity. DNA analysis has uncovered high levels of genetic variation both within and among islands in Melanesia. This area, however, is poorly studied with regard to Y chromosome analysis.
We conducted preliminary Y chromosome analysis on a linguistically diverse panel of unrelated males. Specifically, we chose 30 samples from the Kuot speaking population residing in New Ireland, 30 samples from the Atta speaking population residing in New Britain, 30 samples from an amalgam of Austronesian speaking populations residing in New Britain, and 30 samples from an amalgam of Austronesian speaking populations residing in New Ireland. Using PCR and gel electrophoresis methodology, we typed four markers: YAP, M9, M15, and 50f2/c.
Our data show statistically significant variation among the four sampled populations at the 50f2/c locus. While the Kuot and both Austronesian sample sets were negative for the deletion, the Atta sample included 10 out of 30 50f2/c deleted individuals. This 33% occurrence of the mutation is the highest frequency documented outside of Europe to date. Many population genetic studies have examined the relationship between linguistic affiliation and the pattern and distribution of genetic variation. Our pilot data on the NRY in combination with preliminary chromosome 22 typing suggest this relationship is relevant in New Britain and New Ireland.
A pilot study to assess paleodietary change in northeast Thailand using stable isotopic analysis. Dolores: Thursday morning - April 24, 2003, 8:30-12:00 C.A. King. Dept. of Anthropology, University of Hawaii. Genetics I: Genetic Variation in Primates and Modern Humans Presentation type: poster A pilot study of stable isotopic analysis on prehistoric human bone from the archaeological site of Ban Chiang, northeast Thailand (n=33) was conducted to determine 1) whether isotopic data can be obtained from archaeological human remains from mainland Southeast Asia, and 2) whether secular changes in diet could be detected using carbon and nitrogen isotopic analysis. Results of the pilot study confirmed the methodology was viable and also suggest that dietary changes occurred.
The levels of δ15N, δ sup>13Cco, δ13Cca, and Δ13Cca-co found in the pilot study all suggest the diets of these individuals were highly mixed, with both terrestrial and aquatic proteins. The narrow range of variation in carbon and nitrogen values over time suggests little dietary change. However, analyses of by sex differences within each time period are statistically significant for each carbon and nitrogen values. This may represent differential access to food resources based on status, sex, or both. Stratified wealth is well documented in northeast Thailand but to date no studies have tested differential access to food resources.
Additional research utilizing isotopic values of plant and animal samples collected in northeast Thailand and additional human archaeological samples will refine our interpretation of these dietary changes. From this it may be possible to make trophic level distinctions to assist in explaining the subtle variations in isotopic values found in mainland Southeast Asia.
A preliminary investigation of wildlife, domestic and human use of the Sinya Mine Water Pools in Tanzania. Xavier: Thursday morning - April 24, 2003, 8:30-12:00 P. Nystrom1, P.C. Ashmore2. 1Archaeology & Prehistory, University of Sheffield, 2Dept. of Anthropology, University of Missouri-St. Louis. Human Biology I: Adaptation/Demography/Variation Presentation type: poster Presently, when protecting endangered species or habitats, humans and their domestic animals are usually excluded despite the fact that humans and wildlife have lived along side each other for centuries, but can wildlife exist along side with humans? Between 1956 and 1980 there was an active open-pit mining project in Sinya (northeastern Tanzania). When the mining ended, the pits filled up with water due to the high water table of this region. The pools now serve as year round water sources for wildlife and domestic animals. Sinya, a semiarid acacia scrub habitat, is occupied by traditional Maasai pastoralists, and is the site of a tourist concession that provides local Maasai with a significant tourist income.
A preliminary investigation of the mine pool habitat was conducted in June-July, 2002. Five of nine pools were observed for 87 hours. The focus was to identify the use of the pools as a sustainable water resource by both domestics and wildlife. Seventeen wild mammalian species, 35 species of birds, and five domestic species used the pools regularly. We identified the drinking cycles of domestic and wild species and the number of individuals observed drinking from the pools. These novel fresh water sources sustain a large number of individuals. Preliminary observations and interviews of local Maasai and tourist operators suggest that wildlife populations are increasing (from both high fecundity rates and emigration into the area) despite the presence of domestic animals. Pool use data indicate a complex, articulated and interactive pattern of drinking activities.
A preliminary study of travel routes and spatial mapping in mantled howler monkeys (Alouatta palliata). Xavier: Thursday afternoon - April 24, 2003, 1:30-5:00 P.E. Jelinek1, P.A. Garber1, M.F. Bezanson2, A. DeLuycker3, T. O'Mara4. 1Dept. of Anthropology, University of Illinois, 2Dept. of Anthropology, University of Arizona, 3Dept. of Anthropology, Washington University, 4Dept. of Anthropology, Grand Valley State University. Primate Behavior II: Ecology and Behavior Presentation type: poster Studies of primate foraging and ranging behavior indicate evidence of goal-directed travel and relatively straight-line movement between sequential feeding sites. In the case of mantled howlers (Alouatta palliata) on BCI, Panama, Milton (1980) has argued that group members center their feeding, resting, and ranging activities on a small set of pivotal trees that are visited several times daily. The degree to which this pattern is adopted by mantled howlers at other sites remains unclear.
In this study we present quantitative data on travel routes taken by mantled howlers and address questions concerning howler goal-directed travel and spatial mapping. Data were collected during July and August of 2002 on a group of A. palliata inhabiting a dry tropical forest on Isla de Ometepe, Nicaragua. Over the course of 15 days and 104 hours of observation, all trees the howlers were observed to travel, feed, and rest in were marked (N=299), and distances and angles between trees were measured and mapped. Travel routes were identified by following a focal individual for 6-8 hours per day.
During the course of our study, howlers traveled between 185.5 to 659.5 meters per day. An analysis indicates that whereas 5 paths were reused frequently and accounted for 33% (37/111) of all travel route segments, 43% (48/111) of route segments were used only on one or two occasions. The results suggest that travel in Nicaraguan mantled howlers is characterized by evidence of both route-based travel and the use of varied pathways to reach previously visited feeding and resting sites. Additional relationships between mantled howler ranging, activity patterns, and use of spatial information are discussed.
A preliminary survey and GIS analysis of ring-tailed lemur habitat use in and around Beza-Mahafaly Reserve, Madagascar. Xavier: Thursday afternoon - April 24, 2003, 1:30-5:00 D.C. Whitelaw, M.L. Sauther. Dept. of Anthropology, University of Colorado, Boulder. Primate Behavior II: Ecology and Behavior Presentation type: poster Today's assemblage of lemurs in Madagascar represents only a fraction of their past successful adaptive radiation on the island. Much controversy surrounds the demise of the species that have disappeared from Madagascar's landscape (Burney, 1997). There is a repeating theme, however, of human involvement. Deforestation and habitat fragmentation continue to jeopardize the future of lemurs in Madagascar.
This study demonstrates the usefulness of GIS technology in addressing questions of habitat change by examining ring-tailed lemur habitats both within and outside of Beza-Mahafaly Reserve in Southwestern Madagascar and analyzing the results with a GIS. We located several sub-populations of lemurs within a variety of fragmented and disturbed habitats and conducted ecological measurements to compare these areas to one another. Using a GIS, we were able to generate a map of the area surrounding the reserve and analyze some of the population dynamics that are occurring among these various habitats. Results indicate that more productive habitat, i.e. gallery forest, contains more ring-tailed lemur groups and that ring-tailed lemur groups that have overlapping home ranges are also in areas of more productive habitat.
Not only does this research have implications for the conservation of these lemurs, but it also provides a more complete understanding of how these animals are coping, responding and adapting to human imposed changes on their environment. GIS has become an important tool in helping to analyze the habitats of endangered species (Akcakaya, 1994). Applying this science aids researchers in visualizing and evaluating spatial dynamics in groups of fauna.
A quantitative test of natural selection under changing environmental conditions. Dolores: Thursday morning - April 24, 2003, 8:30-12:00 E.A. Carson. Dept. of Anthropology, University of New Mexico, Albuquerque. Genetics I: Genetic Variation in Primates and Modern Humans Presentation type: poster Model-bound analyses of microevolutionary processes have contributed significantly to our understanding of the mechanisms operating on phenotypic traits. These methods, however, make the important assumption that interaction with the environment is either absent or comparable across data sets, and therefore has little effect on the ultimate existence and dispersal of phenotypic traits. Anthropologists have acknowledged the importance of the environment in the evolution of modern humans, and although recent work has placed increasing emphasis on the environment as the primary catalyst for micro- and macroevolution, actual quantification of its role in these processes has not been attempted.
This study proposes to alter an existing quantitative genetics equation for phenotypic evolution by natural selection (Via and Lande, 1985) to include a term that accounts for temporal changes in broad environmental variables. The ultimate objective is to determine whether the inclusion of environmental variation in evolutionary models produces more accurate estimates of phenotypic diversity than one that equates phenotypic changes with those in the genotype. Data consist of five craniofacial measurements from 269 modern and 29 Pleistocene crania from southeastern Australia. The genetic component, represented by the variance/covariance matrices of trait heritabilities, is balanced by an environmental term that includes temperature, humidity, solar radiation, and air pressure, among others. Differential weighting of the genetic and environmental contributions to the known phenotypic variation yields a model of evolution by natural selection that can account for temporal changes in Australian craniofacial morphology within the natural context of these populations.
A reassessment of variability in the hominoid postcranium: Issues of homology and homoplasy. Palm F: Saturday morning - April 26, 2003, 10:45-11:00 N. Young. Harvard University. Primate Evolution IV: Form and Function Presentation type: podium Talk number: 12 In an analysis of hominoid postcranial variation, Larson (1998) found that many purportedly unique features of the hominoid postcranium were actually much more variable than previously reported and in some cases overlapped with both suspensory (Ateles) and non-suspensory primates. Based on these findings Larson concluded that convergence in the living ape postcranium was a plausible and even likely scenario given the Miocene hominoid fossil record. However, Larson did not distinguish whether non-hominoid overlap with ape similarities occurred in one ape taxon or in many, or whether great apes were more similar to each other than to lesser apes. To address this issue, Larson's postcranial data was reanalyzed using three techniques: cladistic analysis, principle components analysis, and cluster analysis. Results reveal that the postcranial characters have a strong functional signal but still discriminate hominoids and Ateles from all other taxa, great apes from lesser apes, cercopithecines from colobines, and cercopithecoids from platyrrhines. The majority of hominoid overlap with other primates occurs between Ateles and Hylobates, and these similarities are primarily in humeral head characters. Characters in which non-suspensory taxa overlap with ape taxa primarily distinguish Ateles and Hylobates from other primates including great apes. The great apes form a distinct cluster within the suspensory primates. These results suggest that the postcranium of Ateles is primarily convergent with Hylobates, perhaps because of a shared brachiating adaptation, and that the great apes form a relatively distinct postcranial clade. Characters which discriminate Pongo from the African apes are primarily located in the scapula.
A re-evaluation of human and macaque "imitation:" Human children and rhesus macaques do not qualitatively differ in a copying task. Abbey: Saturday morning - April 26, 2003, 8:15-8:30 F. Subiaul, J. Cantlon, H. Lurie, R. Holloway, H. Terrace. Columbia University. Primate Behavior IV: Inter- and Intra-Specific Behavior Presentation type: podium Talk number: 2 Meltzoff and his colleagues have presented evidence, which strongly suggests that humans are endowed with an innate ability to copy the actions of others. However, this has not been the case for primates in general. An extensive review of the non-human primate literature suggests that non-human primates learn from models via simple perceptual mechanisms like stimulus and/or local enhancement (Tomasello and Call, 1997). But human children succeed in similar tasks because they seem to have an understanding of the intention and goals of the model (Nagell, Oguin, & Tomasello, 1993). However, Subiaul et al (2002) using a new imitation paradigm previously demonstrated that when motor confounds are eliminated from the task, adult rhesus macaques can successfully learn a 3 and 4-item list of pictures from an experienced model. Here we present new evidence, comparing the performance of rhesus macaques with that of human children (ages 3.5 to 5.3). Despite the superior memory and attentional abilities of humans, as well as, the unique ability to linguistically encode information, their performance did not qualitatively differ from that of monkeys. These results further confirm our previous conclusions that (1) different neural and cognitive structures may underlie the copying of cognitive information and the copying of motor actions, (2) once motor and tool confounds are adequately controlled, non-human and human performance on a copying task do no qualitatively differ, and (3) the ability to copy abstract information may be a shared-derived catarrhine trait.
A re-examination of purported "Meganthropus" cranial fragments. Palm ABC: Friday morning - April 25, 2003, 8:30-8:45 A.C. Durband. Dept. of Anthropology, University of Tennessee, Knoxville. Hominid Evolution III: Middle and Late Pleistocene Evolution Presentation type: podium Talk number: 3 The genus "Meganthropus" was originally coined for the large mandibular fragment Sangiran 6. Since its introduction, a number of workers have placed both cranial and mandibular specimens into this genus primarily due to their size and robusticity. Many studies have shown that the mandibular specimens attributed to "Meganthropus" merely reflect the more extreme end of a normal range of variation for the fossil species Homo erectus. In the present study, three cranial fragments from Sangiran that have been assigned to "Meganthropus" are examined in an effort to determine whether this placement is justified or if these specimens can be accommodated within H. erectus. The results of this study call into question previous interpretations of this material, and indicate that none of the three specimens can be separated from H. erectus. "Meganthropus" I is interpreted to be a portion of the lateral cranial vault, a position that differs from the original description of this fossil, and the specimen is found to be well within the range for the known H. erectus sample. Likewise, the "Meganthropus" III occipital fragment, a specimen that was difficult to interpret based on earlier descriptions of the fossil, is found to be similar to known examples of Asian H. erectus. Sangiran 31 ("Meganthropus" II) is the only specimen studied that does not immediately group with H. erectus, however even this specimen fits within the recognized H. erectus hypodigm and does not provide adequate evidence for the maintenance of the genus "Meganthropus."
A review of zoonoses transmissible among primates. Palm F: Saturday afternoon - April 26, 2003, 1:15-1:30 J.R. Carter. Texas Tech University. Symposium: Ecology and Primate Zoonoses: Evolutionary, Environmental and Cultural Factors Associated with Emerging Infectious Diseases, Cross-species Transmission, and Nonhuman Primate Conservation Presentation type: podium Talk number: 2 Due to their close evolutionary and often synecological relationships, humans and simians share a broad range of pathogens. The purpose of this paper is to set the background for subsequent papers in this symposium presenting field data regarding cross-species transmissions. Accordingly, there are two key objectives: 1.) to review disease classifications germane to primates and 2.) to provide updated tabular summaries of those transmissible agents which have been demonstrated to infect nonhuman primates. For example, free-ranging primates are recognized as reservoir hosts for a variety of pathogens and presumed in others: bacterioses (e.g., shigellosis bi-directional between captive nonhuman primates and humans), rickettsioses (e.g., Boutonneuse fever in wild vervet monkeys in South Africa), viroses (e.g., forest monkeys are the primary hosts in the "jungle" and "sylvatic" cycles of flaviviruses such as yellow fever among Cercopithecus species in sub-Saharan Africa and dengue fever in several nonhuman primate species in Asia and in South America) and parasitic diseases (e.g., intestinal strongyloidasis is common in Old World nonhuman primates).
Finally, the evidence for co-adaptation and co-speciation between parasites and their primate hosts will be discussed briefly (e.g., Enterobius species of nematode pinworms and the nonhuman primate species they inhabit). This paper will emphasize the evolutionary context of primate zoonoses and the value of field investigations into concurrent infections and immunology in sympatric primates in order to fully appreciate the potential for, as well as the ecological and human socio-behavioral mechanisms of, cross-species transmissions.
A stable isotope and elemental study of South-African Plio-Pleistocene hominins. Palm ABC: Saturday morning - April 26, 2003, 11:15-11:30 M. Sponheimer1, D. de Ruiter2, J. Lee-Thorp3. 1Dept. of Biology, University of Utah, 2Palaeoanthropology Unit for Research and Exploration, Bernard Price Institute for Palaeontology, University of the Witwatersrand, 3Dept. of Archaeology, University of Cape Town. Hominid Evolution VII: Miocene and Pliocene Evolution Presentation type: podium Talk number: 14 A spate of new data on early hominin nutritional ecology has become available in the past few years. Stable isotope data suggest that Plio-Pleistocene hominins consumed large quantities of C4 foods (grasses, sedges, animals eating these foods), sometimes representing more than 50% of their diets. Several possible C4 foods have received attention of late, yet the degree to which these foods could have contributed to the hominid C4 signature remains uncertain. To address this problem, we undertook a modern stable isotope and elemental study of potential hominin foods in Kruger National Park, South Africa. We also include new stable isotope and elemental data from an expanded dataset of hominin and non-hominin fossils from the sites of Swartkrans and Sterkfontein.
Termites are an important potential food resource for early hominins, most recently highlighted by use-wear analysis of bone tools from Swartkrans. Most termite taxa examined in this study were about 50% C4, while several of the hominins were greater than 50% C4. This suggests that termites alone do not account for the high-C4 signature of early hominins. Several researchers have also noted the potential importance of sedge USOs as hominin foods. However, our data show that fewer sedges are C4 than had previously been thought. All told, these data suggest that Plio-Pleistocene hominins were most likely generalist feeders, exploiting a variety of C3 and C4 food resources, including both plant and animal materials.
A strategy for the reduction of mechanical internal work in primates. Cavetto: Saturday afternoon - April 26, 2003, 1:30-5:00 D.A. Raichlen. Dept. of Anthropology, The University of Texas at Austin. Primate Biology VI: Adaptation and Evolution Presentation type: poster Quadrupedal primates have limbs shaped differently than most other mammals. Primates have muscle mass distributed distally on their limbs to control their grasping hands and feet. Most other quadrupeds have limb mass concentrated proximally, presumably to reduce the energy needed to move those limbs (mechanical internal work). Primates would therefore be expected to use more energy during locomotion compared to other mammals of similar body mass. Surprisingly, though, primates have similar energetic costs of locomotion compared to other mammals. This study examines the possibility that primates adjust their gait in order to mitigate the energetic consequences of their distally heavy limbs.
One possible determinant of energetic cost is stride frequency. Since primates differ from most other mammals by using lower stride frequencies at a given speed, this difference may relieve the negative effects of their limb shapes. A model equation for the prediction of mechanical internal work based on body mass distribution and gait characteristics was developed by Minetti (1998). Using this equation, the work done during walking was predicted for three groups: Papio, Canis, and Papio modeled with non-primate stride frequencies. Papio and Canis do not differ in their predicted mechanical internal work when walking naturally, but Papio walking with higher, non-primate stride frequencies does significantly more work than either Papio walking naturally or Canis. These results suggest that primates' lower stride frequencies counteract their distally distributed muscle mass and allow them to do similar amounts of work compared to other mammals, possibly accounting for their similar energetic costs.
A study of the heritability of craniofacial asymmetry. Abbey: Friday morning - April 25, 2003, 10:15-10:30 R.E. Ward1, J.A. Russell2, P.L. Jamison3, J.K. Hartsfield, Jr.2, D. Koller4. 1Dept. of Anthropology, Indiana Univ. Purdue Univ. Indianapolis, 2Dept. of Oral Facial Development, Indiana University School of Dentistry, 3Dept. of Anthropology, Indiana University, 4Dept. of Medical Genetics, Indiana University School of Medicine. Human Biology II: Health and Disease Presentation type: podium Talk number: 10 We examined craniofacial asymmetry in a sample of 178 individuals consisting of 59 pairs of monozygotic twins, 7 pairs of dizygotic twins and 29 sibling pairs to test the hypothesis that there is a measurable heritable component to craniofacial asymmetry. If the hypothesis is correct, we would expect there to be greater correlation between monozygotic twins in asymmetry values than between dizygotic twins (or the genetically equivalent sibling pairs.) Data consisted of previously collected anterior-posterior radiographs. Ten horizontal and eight vertical bilateral variables were measured from standard reference lines. Differences were calculated for paired measurements and tested for directionality using one-sample t-tests. All horizontal variables displayed significant left side dominance and six of the eight vertical variables showed significant directionality to the right in all subsamples. Heritability estimates were obtained from the intraclass correlation coefficients for all differences using weighted asymmetry values [(*L-R*)/.5(L+R)] to control for directionality and differences in measurement magnitude. Heritability values ranged from .35 to -.53 with a mean value of .04 and a standard deviation of .22. Thus, there is little evidence of a pronounced heritability of facial asymmetry, suggesting that most craniofacial asymmetry is environmental or functional in origin.
Acquirement of social ranks of females in one group of Taiwanese macaques (Macaca cyclopis) at Fushan Experimental Forest, Taiwan. Xavier: Thursday afternoon - April 24, 2003, 1:30-5:00 H-H. Su. Dept. of Anthropology, Rutgers, the State University of New Jersey. Primate Behavior II: Ecology and Behavior Presentation type: poster Maternal rank inheritance and youngest ascendancy have been argued to apply to dominance acquirement in female macaques. Youngest ascendancy is observed in some Japanese macaque groups and in one rhesus monkey group. However, it has not been observed in Barbary macaques. My studies of one group of Taiwanese macaques at Fushan show that females acquire social ranks below and adjacent to their mothers. Younger sisters in two of three sister pairs studied are dominant to their older sisters.
I conducted the field observations on the macaque group from July of 1998 through July of 2000 as well as in October of 2001 and July of 2002. Social ranks of females in the study group are determined by direction of aggression and displacement displayed during their dyadic agonistic interactions. During the study five daughters turned sexually mature and acquired social ranks just below their mothers, and no outrankings have been observed.
Three pairs of sisters in the group were studied from 7/16/02 through 7/26/02 to determine their dominance relationships. During a total of 79.5-hr observation of the entire group, 37, 31 and 38 focal samples of 10 minutes were collected from the three sister pairs. Data on aggression and submission that occurred in each pair were collected to calculate the dominance index. Based on the index, two of three younger sisters are dominant to their older sisters. Effects of the presence or absence of their mothers in the group on social ranks of the younger sisters are presented here.
Addressing student misconceptions about human evolution. Palm ABC: Thursday afternoon - April 24, 2003, 2:15-2:30 D.L. Cunningham, D.J. Wescott. University of Missouri-Columbia. Symposium: Teaching Physical Anthropology: Strategies for Dealing with Controversial Topics Presentation type: podium Talk number: 6 Misconceptions about science and evolution are widespread among undergraduates. These include: confusion between the vernacular and the scientific meaning of the word "theory", Lamarckian ideas about inheritance, misunderstandings about mutation, under appreciating the importance of variation in a species, teleological views of natural selection, difficulties in population-level thinking, and confusion about the types of phenomena that science is able to address. Even upon completion of science classes, these mistaken views are still often held by students. If students graduate college without an understanding of the processes of science, and the basics of human evolution, it is unlikely that this situation will ever be remedied. Misunderstandings about human evolution have fueled the push to include "intelligent design" curricula in the science classroom. If science is to triumph over politics when curriculum decisions are made, it is imperative that instructors do a good job of addressing scientific misconceptions and teaching science to non-science majors. That way, parents and members of the school boards and local legislatures can be fully informed.
This paper will review the common scientific misconceptions held by undergraduates, and will offer suggestions to improve undergraduates' understanding of human evolution in the physical anthropology classroom. Making such misconceptions explicit in class, paired-problem solving strategies, and the use of a historically rich curriculum are all methods that improve students' understanding. Additionally, we will present data from a questionnaire administered to an introductory physical anthropology class that illustrate students' major misconceptions about human evolution.
Adult stature estimation from the calcaneus of South African blacks. Colonnade: Friday afternoon - April 25, 2003, 2:30-6:00 M.A. Bidmos, S.A. Asala. School of Anatomical Sciences, University of the Witwatersrand. Forensic Anthropology Presentation type: poster Stature is an important factor in establishing the identity of a person in the living as well as in the skeletonized state. When stature is estimated from the bones of the limbs, regression equations, which estimate the ratios of the bones to the height of the individual, are generated. The majority of the bones that have been used are the long bones. The calcaneus has been used for estimating stature only in the American whites and blacks (Holland, 1994). The regression equations that he generated were found to be useful for stature estimation in these population groups. Since the calcaneus has not been used for the same purpose in South Africa, the aim of this study was to derive regression equations that will allow this bone to be used for stature estimation amongst South African blacks. A total of 116 complete skeletons (60 males and 56 females) were selected from the Raymond A. Dart Collection of Human Skeletons, School of Anatomical Sciences, University of the Witwatersrand, Johannesburg. The total skeletal heights of these sets of skeleton were calculated using Fully's (1956) anatomical method. Nine calcaneal parameters were measured and regressed against the total skeletal heights using univariate and multivariate regression methods. Regression equations were therefore obtained for use in estimating stature from the calcaneus of the South African black population. The standard error of estimate that was obtained when univariate regression analysis was done was higher than the corresponding values following multivariate regression analysis. In both cases, the standard errors of estimate compared well with the values that have been obtained for fragmentary long bones by previous authors.
Age variation in isotopic and histological profiles in the Kulubnarti R-Group ( 1000CE - 1550 CE) from Sudanese Nubia. Dolores: Saturday afternoon - April 26, 2003, 1:30-5:00 E.A. Quinn1, J. Kingston1, G. J. Armelagos1, D. Van Gerven2. 1Dept. of Anthropology, Emory University, 2Dept. of Anthropology, University of Colorado, Boulder. Skeletal Biology VI: Bone Chemistry and Morphology Presentation type: poster The Kulubnarti population provides a unique opportunity to develop isotopic profiles reflecting aspects of diet that can assessed in a well established framework of life history patterns. Much of the previous work, however, has been limited to the adult segment of the population. In this paper, we have included subadults of the R-group population in our analysis. As childhood represents a vulnerable stage in the human lifespan, and overall childhood health has been found reflective of population success, analysis of individuals that did not survive this critical period can aid in a biocultural reconstruction of life histories. Collagen, isolated from ribs, was analyzed isotopically for both carbon and nitrogen isotopes. In addition, a thin section was prepared at the site of the original cut on each rib, and examined microscopically. The objectives were multi-facetted, to examine differences in isotopic ratios between age groups, and to examine isotopic differences matched with histological growth profiles. With the exception of a change in δ13C and δ15N values associated with the weaning transition, preliminary analyses indicates that variation between age groups was statistically insignificant from variation within age categories. Histological analysis allowed for an examination of variation in bone growth, which would then be examined with respect to isotopic variation. Isotopic variation between diaphyseal and epiphyseal areas of the bone was also analyzed.
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