Matching Items (31)
Description
The ability of Neandertals to cope with the oscillating climate of the late Pleistocene and the extent to which these climate changes affected local Neandertal habitats remain unanswered anthropological topics of considerable scientific interest. Understanding the impact of climatic instability on Neandertals is critical for reconstructing the behaviors of our closest fossil relatives and possibly identifying factors that contributed to their extinction. My work aimed to test the hypotheses that 1) cold climates stressed Neandertal populations, and 2) that global climate changes affected local Neandertal habitats. An analysis of Neandertal butchering on Cervus elaphus, Rangifer tarandus, and Capreolus capreolus skeletal material deposited during global warm and cold phases from two French sites - Pech de l'Azé IV and Roc de Marsal - was conducted to assess the impact of climate change on butchering strategies and resource extraction. Results from a statistical analysis of surface modification on all marrow yielding long bones, including the 1st phalanx, demonstrated that specimens excavated from the cold levels at each cave have more cut marks (Wald χ2= 51.33, p= <0.001) and percussion marks (Wald χ2= 4.92, p= 0.02) than specimens from the warm levels after controlling for fragment size. These results support the hypothesis that Neandertals were nutritionally stressed during glacial cycles. The hypothesis that global climates affected local habitats was tested through radiogenic strontium isotopic reconstruction of large herbivore mobility patterns (e.g., Bison, Equus, Cervus and Rangifer), because it is known that in the northern hemisphere, mammals migrate less in warm, well-vegetated environments, but more in cold, open environments. Identifying isotopic variation in mammalian fossils enables mobility patterns to be inferred, providing an indication of whether environments at Pech de l'Azé IV and Roc de Marsal tracked global climates. Results from this study indicate that Neandertal prey species within the Dordogne Valley of France did not undertake long distance round-trip migrations in glacial or interglacial cycles, maintaining the possibility that local habitats did not change in differing climatic cycles. However, because Neandertals were nutritionally stressed the most likely conclusion is that glacial cycles decreased herbivore populations, thus stressing Neandertals.
ContributorsHodgkins, Jamie Melichar (Author) / Marean, Curtis W (Thesis advisor) / Reed, Kaye E (Thesis advisor) / Knudson, Kelly J. (Committee member) / Spencer, Lillian M (Committee member) / Arizona State University (Publisher)
Created2012
Description
Despite the critical role that the vertebral column plays in postural and locomotor behaviors, the functional morphology of the cervical region (i.e., the bony neck) remains poorly understood, particularly in comparison to that of the thoracic and lumbar sections. This dissertation tests the hypothesis that morphological variation in cervical vertebrae reflects differences in positional behavior (i.e., suspensory vs. nonsuspensory and orthograde vs. pronograde locomotion and postures). Specifically, this project addresses two broad research questions: (1) how does the morphology of cervical vertebrae vary with positional behavior and cranial morphology among primates and (2) where does fossil hominoid morphology fall within the context of the extant primates. Three biomechanical models were developed for the primate cervical spine and their predictions were tested by conducting a comparative analysis using a taxonomically and behaviorally diverse sample of primates. The results of these analyses were used to evaluate fossil hominoid morphology. The two biomechanical models relating vertebral shape to positional behaviors are not supported. However, a number of features distinguish behavioral groups. For example, the angle of the transverse process in relation to the cranial surface of the vertebral body--a trait hypothesized to reflect the deep spinal muscles' ability to extend and stabilize the neck--tends to be greater in pronograde species; this difference is in the opposite of the direction predicted by the biomechanical models. Other traits distinguish behavioral groups (e.g., spinous process length and cross-sectional area), but only in certain parts of the cervical column. The correlation of several vertebral features, especially transverse process length and pedicle cross-sectional area, with anterior cranial length supports the predictions made by the third model that links cervical morphology with head stabilization (i.e., head balancing). Fossil hominoid cervical remains indicate that the morphological pattern that characterizes modern humans was not present in Homo erectus or earlier hominins. These hominins are generally similar to apes in having larger neural arch cross-sectional areas and longer spinous processes than modern humans, likely indicating the presence of comparatively large nuchal muscles. The functional significance of this morphology remains unclear.
ContributorsNalley, Thierra Kénnec (Author) / Kimbel, William H. (Thesis advisor) / Reed, Kaye (Committee member) / Shapiro, Liza (Committee member) / Arizona State University (Publisher)
Created2013
Description
Facial projection--i.e., the position of the upper face relative to the anterior cranial fossa--is an important component of craniofacial architecture in primates. Study of its variation is therefore important to understanding the bases of primate craniofacial form. Such research is relevant to studies of human evolution because the condition in
Homo sapiens--in which facial projection is highly reduced, with the facial skeleton located primarily inferior (rather than anterior) to the braincase--is derived vis-à-vis other primates species, including others in the genus Homo. Previous research suggested that variation in facial projection is explained by: (1) cranial base angulation; (2) upper
facial length; (3) anterior cranial base length; (4) anterior sphenoid length; and/or (5) anterior middle cranial fossa length. However, previous research was based on taxonomically narrow samples and relatively small sample sizes, and comparative data on facial projection in anthropoid primates, with which these observations could be
contextualized, do not currently exist.
This dissertation fills this gap in knowledge. Specifically, data corresponding to the hypotheses listed above were collected from radiographs from a sample of anthropoid primates (N = 37 species; 756 specimens) . These data were subjected to phylogenetically-controlled multiple regression analyses. In addition, multivariate and univariate models were statistically compared, and the position of Homo sapiens relative to univariate and multivariate regression models was evaluated.
The results suggest that upper facial length, anterior cranial base length, and, to a lesser extent, cranial base angle are the most important predictors of facial projection. Homo sapiens conforms to the patterns found in anthropoid primates, suggesting that these same factors explain the condition in this species. However, a consideration of the
evidence from the fossil record in the context of these findings suggests that upper facial length is the most likely cause of the extremely low degree of facial projection in Homo sapiens. These results downplay the role of the brain in shaping the form of the human cranium. Instead, these results suggest that reduction in facial skeleton size--which may
be due to changes in diet--may be more important than previously suggested.
Homo sapiens--in which facial projection is highly reduced, with the facial skeleton located primarily inferior (rather than anterior) to the braincase--is derived vis-à-vis other primates species, including others in the genus Homo. Previous research suggested that variation in facial projection is explained by: (1) cranial base angulation; (2) upper
facial length; (3) anterior cranial base length; (4) anterior sphenoid length; and/or (5) anterior middle cranial fossa length. However, previous research was based on taxonomically narrow samples and relatively small sample sizes, and comparative data on facial projection in anthropoid primates, with which these observations could be
contextualized, do not currently exist.
This dissertation fills this gap in knowledge. Specifically, data corresponding to the hypotheses listed above were collected from radiographs from a sample of anthropoid primates (N = 37 species; 756 specimens) . These data were subjected to phylogenetically-controlled multiple regression analyses. In addition, multivariate and univariate models were statistically compared, and the position of Homo sapiens relative to univariate and multivariate regression models was evaluated.
The results suggest that upper facial length, anterior cranial base length, and, to a lesser extent, cranial base angle are the most important predictors of facial projection. Homo sapiens conforms to the patterns found in anthropoid primates, suggesting that these same factors explain the condition in this species. However, a consideration of the
evidence from the fossil record in the context of these findings suggests that upper facial length is the most likely cause of the extremely low degree of facial projection in Homo sapiens. These results downplay the role of the brain in shaping the form of the human cranium. Instead, these results suggest that reduction in facial skeleton size--which may
be due to changes in diet--may be more important than previously suggested.
ContributorsRitzman, Terrence (Author) / Schwartz, Gary T (Thesis advisor) / Kimbel, William H. (Committee member) / Kaufman, Jason (Committee member) / Arizona State University (Publisher)
Created2014
Description
Arguments of human uniqueness emphasize our complex sociality, unusual cognitive capacities, and language skills, but the timing of the origin of these abilities and their evolutionary causes remain unsolved. Though not unique to primates, kin-biased sociality was key to the success of the primate order. In contrast to ancestral solitary mammals, the earliest primates are thought to have maintained dispersed (non-group living) social networks, communicating over distances via vocalizations and scent marks. If such ancestral primates recognized kin, those networks may have facilitated the evolution of kin-biased sociality in the primate order and created selection for increased cognitive and communicative abilities. I used the gray mouse lemur (Microcebus murinus) to model whether vocalizations could have facilitated matrilineal and patrilineal kin recognition in ancestral primates. Much like mouse lemurs today, ancestral primates are thought to have been small-bodied, nocturnal creatures that captured insects and foraged for fruit in the thin, terminal ends of tree branches. Thus, the mouse lemur is an excellent model species because its ecological niche is likely to be similar to that of ancestral primates 55-90 million years ago. I conducted playback experiments in Ankarafantsika National Park, Madagascar testing whether mouse lemur agonistic calls contain matrilineal kin signatures and whether the lemurs recognize matrilineal kin. In contrast to large-brained, socially complex monkeys with frequent coalitionary behavior, mouse lemurs did not react differently to the agonistic calls of matrilineal kin and nonkin, though moderate signatures were present in the calls. I tested for patrilineal signatures and patrilineal kin recognition via mating and alarm calls in a colony with known pedigree relationships. The results are the first to demonstrate that a nocturnal, solitary foraging mammal gives mating calls with patrilineal signatures and recognizes patrilineal kin. Interestingly, alarm calls did not have signatures and did not facilitate kin recognition, suggesting that selection for kin recognition is stronger in some call types than others. As this dissertation is the first investigation of vocal kin recognition in a dispersed-living, nocturnal strepsirrhine primate, it greatly advances our knowledge of the role of vocal communication in the evolution of primate social complexity.
ContributorsKessler, Sharon E (Author) / Nash, Leanne (Thesis advisor) / Reed, Kaye (Thesis advisor) / Radespiel, Ute (Committee member) / Zimmermann, Elke (Committee member) / Arizona State University (Publisher)
Created2014
Description
Extremely thick cranial vaults have been noted as a diagnostic characteristic of Homo erectus since the first fossil of the species was identified, but potential mechanisms underlying this seemingly unique trait have not been rigorously investigated. Cranial vault thickness (CVT) is not a monolithic trait, and the responsiveness of its layers to environmental stimuli is unknown. Identifying factors that affect CVT would be exceedingly valuable in teasing apart potential contributors to thick vaults in the Pleistocene. Four hypotheses were tested using CT scans of skulls of more than 1100 human and non-human primates. Data on total frontal, parietal, and occipital bone thickness and bone composition were collected to test the hypotheses: H1. CVT is an allometric consequence of brain or body size. H2. Thick cranial vaults are a response to long, low cranial vault shape. H3. High masticatory stress causes localized thickening of cranial vaults. H4. Activity-mediated systemic hormone levels affect CVT. Traditional comparative methods were used to identify features that covary with CVT across primates to establish behavior patterns that might correlate with thick cranial vaults. Secondly, novel experimental manipulation of a model organism, Mus musculus, was used to evaluate the relative plasticity of CVT. Finally, measures of CVT in fossil hominins were described and discussed in light of the extant comparative and experimental results. This dissertation reveals previously unknown variation among extant primates and humans and illustrates that Homo erectus is not entirely unique among primates in its CVT. The research suggests that it is very difficult to make a mouse grow a thick head, although it can be genetically programmed to have one. The project also identifies a possible hominin synapomorphy: high diploë ratios compared to non-human primates. It also found that extant humans differ from non-human primates in overall pattern of which cranial vault bones are thickest. What this project was unable to do was definitively provide an explanation for why and how Homo erectus grew thick skulls. Caution is required when using CVT as a diagnostic trait for Homo erectus, as the results presented here underscore the complexity inherent in its evolution and development.
ContributorsCopes, Lynn (Author) / Kimbel, William H. (Thesis advisor) / Schwartz, Gary T (Committee member) / Spencer, Mark A. (Committee member) / Ravosa, Matthew J. (Committee member) / Arizona State University (Publisher)
Created2012
Description
The pattern and strength of genetic covariation is shaped by selection so that it is strong among functionally related characters and weak among functionally unrelated characters. Genetic covariation is expressed as phenotypic covariation within species and acts as a constraint on evolution by limiting the ability of linked characters to evolve independently of one another. Such linked characters are "constrained" and are expected to express covariation both within and among species. In this study, the pattern and magnitude of covariation among aspects of dental size and shape are investigated in anthropoid primates. Pleiotropy has been hypothesized to play a significant role in derivation of derived hominin morphologies. This study tests a series of hypotheses; including 1) that negative within- and among-species covariation exists between the anterior (incisors and canines) and postcanine teeth, 2) that covariation is strong and positive between the canines and incisors, 3) that there is a dimorphic pattern of within-species covariation and coevolution for characters of the canine honing complex, 4) that patterns of covariation are stable among anthropoids, and 5) that genetic constraints have been a strong bias on the diversification of anthropoid dental morphology. The study finds that patterns of variance-covariance are conserved among species. Despite these shared patterns of variance-covariance, dental diversification has frequently occurred along dimensions not aligned with the vector of genetic constraint. As regards the canine honing complex, there is no evidence for a difference in the pleiotropic organization or the coevolution of characters of the complex in males and females, which undermines arguments that the complex is selectively important only in males. Finally, there is no evidence for strong or negative pleiotropy between any dental characters, which falsifies hypotheses that predict such relationships between incisors and postcanine teeth or between the canines and the postcanine teeth.
ContributorsDelezene, Lucas (Author) / Kimbel, William H. (Thesis advisor) / Schwartz, Gary T (Committee member) / Spencer, Mark (Committee member) / Verrelli, Brian C (Committee member) / Arizona State University (Publisher)
Created2011
Description
This research focuses upon the intersection of social complexity and leadership among commoners in complex societies as expressed through mortuary ritual. I study how ideology, materialized through treatment of the deceased body, was a potential source of power among commoners in ancient Maya society and how this materialization changed through time. Mortuary data are drawn from mid-level settlements of the Belize River Valley, located in western Belize within the eastern Maya lowlands. The primary research question addresses whether mid-level leaders in the Belize River Valley targeted certain human bodies for ancestral veneration through tomb re-entry and ritual interaction with skeletal remains. The ritual-political strategy of mid-level leaders is measured using archaeothanatology, an analysis of grave taphonomy based on forensic data, to reconstruct cultural beliefs about death based on treatment of deceased bodies, radiogenic strontium isotope analysis to reconstruct residential history, and analysis of dental metrics to assess biological kinship. While preservation of osseous material was poor, results indicate that the frequency of disarticulated and secondary burials was higher in eastern structures than in other locales, although eastern structures were not the only loci of these types of deposits. Overall, it does not seem like secondary burials were regularly and purposefully created for use as ritual objects or display. Radiogenic strontium isotope data enrich this analysis by showing that eastern structures were not a burial locale exclusive to individuals who spent their childhood in the Belize Valley. Data from upper-level eastern structures also suggests that within that part of society local birth did not guarantee interment in a local manner; perhaps the social network created during one's life shaped treatment in death more than residential origin. Biological distance analyses were inconclusive due to missing data. Comparison of mortuary practices to nearby regions shows distinct mortuary patterning across space and time. This is consistent with reconstructions of ancient Maya sociopolitical organization as regionally diverse and moderately integrated.
ContributorsNovotny, Anna (Author) / Buikstra, Jane E. (Thesis advisor) / Carr, Christopher (Committee member) / Robin, Cynthia (Committee member) / Astor-Aguilera, Miguel (Committee member) / Tiesler, Vera (Committee member) / Knudson, Kelly J. (Committee member) / Arizona State University (Publisher)
Created2015
Description
Social identities are fundamental to the way individuals and groups define themselves. Archaeological approaches to social identities in the Andes emphasize the importance of group identities such as ethnicity and community identity, but studies of gender and age identities are still uncommon. In this dissertation, I build on these earlier approaches to Andean social identities and consider community, gender, and age identities at the site of Chiribaya Alta using case studies.
The coastal Ilo Chiribaya polity is associated with the Andean Late Intermediate Period in the lower Osmore drainage of southern Peru. Previous analyses indicate that Chiribaya sites in this area formed a señorío, an Andean chiefdom with separate occupational groups of fishers and farmers. The most complex excavated Chiribaya site in this region is Chiribaya Alta. At this time, excavations have sampled nine of the cemeteries present at the site. Two of these cemeteries, four and seven, have the most elaborate burials at the site and are each associated with different occupational communities.
This dissertation examines community, gender, and age identities at Chiribaya Alta through the use of three case studies. The first case study argues that the iconographic designs on coca bags interred with the dead signified occupational community identities. Coca bags buried in cemetery four have designs relating to mountains and farming, whereas those from cemetery seven have symbols associated with water. These designs correspond to the occupational community groups associated with each of these cemeteries. The second case study uses grave good presence and absence to examine the nature of gender roles and identity at Chiribaya Alta. Multiple correspondence analysis indicates that normative gender roles are reflected in grave good assemblages, but that gender identity was flexible at the individual level. The final case study presents newly generated age-at-death estimations using transition analysis combined with mortuary analyses to explore the manner in which gender and age intersect for older individuals at Chiribaya Alta. This final paper argues that there is an elderly identity present amongst individuals at Chiribaya Alta and that gender and age intersect to impact the lives of older men and women differently.
The coastal Ilo Chiribaya polity is associated with the Andean Late Intermediate Period in the lower Osmore drainage of southern Peru. Previous analyses indicate that Chiribaya sites in this area formed a señorío, an Andean chiefdom with separate occupational groups of fishers and farmers. The most complex excavated Chiribaya site in this region is Chiribaya Alta. At this time, excavations have sampled nine of the cemeteries present at the site. Two of these cemeteries, four and seven, have the most elaborate burials at the site and are each associated with different occupational communities.
This dissertation examines community, gender, and age identities at Chiribaya Alta through the use of three case studies. The first case study argues that the iconographic designs on coca bags interred with the dead signified occupational community identities. Coca bags buried in cemetery four have designs relating to mountains and farming, whereas those from cemetery seven have symbols associated with water. These designs correspond to the occupational community groups associated with each of these cemeteries. The second case study uses grave good presence and absence to examine the nature of gender roles and identity at Chiribaya Alta. Multiple correspondence analysis indicates that normative gender roles are reflected in grave good assemblages, but that gender identity was flexible at the individual level. The final case study presents newly generated age-at-death estimations using transition analysis combined with mortuary analyses to explore the manner in which gender and age intersect for older individuals at Chiribaya Alta. This final paper argues that there is an elderly identity present amongst individuals at Chiribaya Alta and that gender and age intersect to impact the lives of older men and women differently.
ContributorsSchach, Emily Ann (Author) / Buikstra, Jane E. (Thesis advisor) / Knudson, Kelly J. (Committee member) / Geller, Pamela L. (Committee member) / Arizona State University (Publisher)
Created2019
Description
East African extensional basins have played a crucial role in revealing the evolution and characteristics of the early stages of continental rifting and for providing the geological context of hominin evolution and innovation. The numerous volcanic eruptions, rapid sedimentation and burial, and subsequent exposure through faulting and erosion, provide excellent conditions for the preservation of tectonic history, paleoenvironment data, and vertebrate fossils. The reconstruction of depositional environments and provision of geochronologic frameworks for hominin sites have been largely provided by geologic investigations in conjunction with paleontological studies, like the Ledi-Geraru Research Project (LGRP). High-resolution paleoclimate records that can be directly linked to hominin fossil outcrops have been developed by the Hominin Sites and Paleolakes Drilling Project (HSPDP) which collected sedimentary-paleolake cores at or near key hominin fossil sites.
Two chapters of this dissertation are a result of research associated with the HSPDP. For HSPDP, I establish a tephrostratigraphic framework for the drill cores from the Northern Awash (Afar, Ethiopia) and Baringo-Tugen Hills-Barsemoi (Kenya) HSPDP sites. I characterize and fingerprint tephra through glass shard and feldspar phenocryst geochemistry. From tephra geochemical analyses, I establish chronostratigraphic ties between the HSPDP cores’ high-resolution paleoclimate records to outcrop stratigraphy which are associated with hominin fossils sites.
Three chapters of this dissertation are a result of field work with the LGRP. I report new geological investigations (stratigraphic, tectonic, and volcanic) of two previously unmapped regions from the eastern Ledi-Geraru (ELG), Asboli and Markaytoli. Building upon this research I present interpretations from tephra analyses, detailed stratigraphic analyses, and geologic mapping, of the Pleistocene (~2.6 to < 2.45 Ma) basin history for the LGRP. My work with the LGRP helps to reconstruct a more complete Early Pleistocene depositional and geologic history of the lower Awash Valley.
Overall, this dissertation contributes to the reconstruction of hominin paleoenvironments and the geochronological framework of the Pliocene and Pleistocene faunal/hominin records. It further contributes to rift basin history in East Africa by elaborating the later structural and stratigraphic history of the lower Awash region.
Two chapters of this dissertation are a result of research associated with the HSPDP. For HSPDP, I establish a tephrostratigraphic framework for the drill cores from the Northern Awash (Afar, Ethiopia) and Baringo-Tugen Hills-Barsemoi (Kenya) HSPDP sites. I characterize and fingerprint tephra through glass shard and feldspar phenocryst geochemistry. From tephra geochemical analyses, I establish chronostratigraphic ties between the HSPDP cores’ high-resolution paleoclimate records to outcrop stratigraphy which are associated with hominin fossils sites.
Three chapters of this dissertation are a result of field work with the LGRP. I report new geological investigations (stratigraphic, tectonic, and volcanic) of two previously unmapped regions from the eastern Ledi-Geraru (ELG), Asboli and Markaytoli. Building upon this research I present interpretations from tephra analyses, detailed stratigraphic analyses, and geologic mapping, of the Pleistocene (~2.6 to < 2.45 Ma) basin history for the LGRP. My work with the LGRP helps to reconstruct a more complete Early Pleistocene depositional and geologic history of the lower Awash Valley.
Overall, this dissertation contributes to the reconstruction of hominin paleoenvironments and the geochronological framework of the Pliocene and Pleistocene faunal/hominin records. It further contributes to rift basin history in East Africa by elaborating the later structural and stratigraphic history of the lower Awash region.
ContributorsGarello, Dominique Ines (Author) / Arrowsmith, Ramon (Thesis advisor) / Campisano, Chris J (Thesis advisor) / Reed, Kaye (Committee member) / Feary, David (Committee member) / Wittmann, Axel (Committee member) / Arizona State University (Publisher)
Created2019
Description
Providing an environmental context to early hominins is as important as describing the hominin fossils themselves, because evolutionary processes are tightly linked to everchanging ecosystems that vary across space and through time. An optimal understanding of ecosystems changes is critical to formulate and test hypotheses regarding human evolution and adaptation. Fortunately, the fossil record has yielded abundant remains of mammals which can be used to explore the possible causal relationships between environmental change and mammal – including hominin –evolution. Although many studies have already been conducted on this topic, most of them are framed at large spatial and temporal scales. Instead, this dissertation focuses on the evolution and paleoecology of only one group of mammals (the Suidae) in a specific geographical area (lower Awash Valley in Ethiopia) and within a constrained time frame (3.8–2.6 Ma). Three dissertation papers address: 1) changes in suid taxonomic composition in relation to Late Pliocene faunal turnover ~2.8 Ma in the Lee-Adoyta basin, Ledi-Geraru; 2) comparisons of suid diets from Hadar (~3.45–2.95 Ma) with respect to those of Kanapoi (~4.1 Ma, West Turkana, Kenya); 3) the dietary ecology of the suids from Woranso-Mille (~3.8–3.2 Ma). Results of these papers show that 1) after ~2.8 Ma there is a replacement of suid species that is coupled with low relative abundance of suids. This is compatible with more open and/or arid environments at this time; 2) suid dietary breadth was broader in Hadar than in Kanapoi, but this is mostly driven by the dietary niche space occupied by Kolpochoerus in Hadar, a suid genus absent from Kanapoi; 3) suid diets vary both temporally and geographically within the lower Awash Valley. Kolpochoerus incorporates more C4 resources (e.g., grasses) in its diet after ~3.5 Ma and in general, suids after ~3.5 Ma in Woranso-Mille had C4-enriched diets in comparison with those from nearby Hadar and Dikika. Presumably, the changes in suid communities (relative abundance and taxonomic composition) and dietary shifts observed in suids were triggered by climatic and habitat changes that also contributed to shape the behavioural and morphological evolution of early hominins.
ContributorsAguilar Lazagabaster, Ignacio (Author) / Reed, Kaye E (Thesis advisor) / Kimbel, William H. (Committee member) / Ungar, Peter S. (Committee member) / Arizona State University (Publisher)
Created2018