For young animals, surviving the first year of nutritional independence requires rapid development of effective foraging behaviour before the onset of terminal starvation. Grey seal (Halichoerus grypus) pups are abandoned on the natal colony after a brief (15-21 days) suckling period and must learn to dive and forage without parental instruction. Regional and sex-specific differences in diet and foraging behaviour have been described for adults and juveniles, but the early-life behaviour of pups during the critical first months at sea remains poorly understood. This thesis investigates sources of intrinsic and extrinsic variation in the development of foraging behaviour and resource selection in grey seal pups. The studies presented here feature tracking and dive data collected from 52 recently-weaned pups, tagged at six different breeding colonies in two geographically-distinct regions of the United Kingdom (UK). Original aspects of this thesis include: (Chapter I) a comprehensive review of analytical methods for inferring foraging behaviour from tracking and dive data in pinnipeds; (Chapter II) description and comparison of regional and sex differences in movements and diving characteristics of recently-weaned pups during their first trips at sea; (Chapter III) implementation of a novel generalized hidden Markov modelling (HMM) technique to investigate the development of foraging movement patterns whilst accounting for sources of intrinsic (age, sex) and extrinsic (regional) variation; and (Chapter IV) the first analysis of grey seal pup foraging habitat preference, incorporating behavioural inferences from HMMs and investigating changes in preference through time.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-07T14:04:17Z No. of bitstreams: 1 Anailza Cristina Galdino da Silva.pdf: 3576171 bytes, checksum: 2c45b933754794f02c92384fb72c8162 (MD5) / Made available in DSpace on 2017-02-07T14:04:17Z (GMT). No. of bitstreams: 1 Anailza Cristina Galdino da Silva.pdf: 3576171 bytes, checksum: 2c45b933754794f02c92384fb72c8162 (MD5) Previous issue date: 2010-02-19 / This study aimed to describe morphologically the ontogenetic initial development of the freshwater anchovy, Anchoviella vaillanti, which is endemic to the São Francisco river basin. We analyzed 132 specimens (SL = 1,3-51 mm) obtained from hauls made with a 500 μm mesh conical-cylindrical plankton net in quarterly samplings in different stretches of the Sobradinho reservoir from January 2002 to January 2004. Individuals were classified into the following phases: larvae – yolk-larval,preflexion, flexion and postflexion stage - and juvenile. We measured the morphometric data, standard length (SL), preanal length (PAL),prepelvic length (PPVL), prepectoral length (PPL), predorsal length (PDL), head length (HL), head depth (HD), eye diameter (ED), and body depth (BD). Some specimens were cleared and stained for evidencing and detailing internal structures, counting of preanal, postanal and total vertebrae, pectoral (P), dorsal (D), pelvic (V), anal (A) and caudal ( C) fin rays and the relative position of dorsal and anal fins insertion. During the larval stage, the body ranged from very elongate to elongate, and the head and the eye both from small to moderate. In juveniles, body varied from elongate to moderate, the head was moderate, and the eye from moderate to large. Prefin lengths in relation to SL ranged from 61.5 to 79.2% for PAL; 51.8 to 72.9% for PDL; 10.7 - 29,2% for PPL and 37.8 - 47, 2% for PPVL. HL ranged from 7.9 - 29,2%; HD from 5.7 - 19.2%; BD from 6.3 to 27.1%; and ED from 16.7 - 42.9% HL. The total vertebrae number in A. vaillanti ranges from 36 to 39 and myomere number ranges from 31 to 45. Dorsal fin insertion varies between the 14th and the 18th precaudal vertebrae and the anal fin insertion varies between 21st and 24th precaudal vertebrae. The sequence of first fin ray formation was D, C, A, V and P. The final number of rays among them, however, is attained in the following order: D and A in the flexion stage and P, V and C in the postflexion stage. In the lower São Francisco River, A. vaillanti may occur sympatrically with A.lepidentostole and may be distinguished by the lower number of dorsal fin rays (15-16 versus 12-13 in A. vaillanti), lower vertebrae count (40 versus 37-40) and greater pre-pectoral length(14-16 % SL versus 22,8-28,9% SL). / Este estudo teve como objetivo descrever morfologicamente o desenvolvimento ontogênico inicial da manjuba de água doce Anchoviella vaillanti, endêmica da bacia do rio São Francisco. Foram analisados 132 exemplares (CP= 1,3-51 mm) obtidos através de arrastos realizados com rede de plâncton cônico-cilíndrica com malha de 500μm, em amostragens trimestrais no reservatório de Sobradinho entre janeiro de 2002 e janeiro de 2004. Os indivíduos foram classificados nas fases: larval - estágios larval vitelino, pré-flexão, flexão e pós-flexão - e juvenil. Foram mensurados os dado morfométricos, comprimento padrão (CP), comprimento pré-anal (CPA), comprimento pré-pélvica (CPPV), comprimento pré-peitoral (CPP), comprimento pré-dorsal (CPD), comprimento da cabeça (CC), altura da cabeça (AC),diâmetro do olho (DO), e altura do corpo (ACP). Alguns exemplares foram diafanizados para evidenciação e detalhamento de estruturas internas, contagem de vértebras pré-anal, pós-anal e total, raios das nadadeiras peitorais (P), dorsal (D), pélvicas (V), anal(A) e caudal (C), bem como a posição relativa de inserção das nadadeiras dorsal e anal. Durante a fase larval, o corpo variou de muito alongado a alongado, a cabeça de pequena a moderada e o olho de pequeno a moderado. Na fase juvenil, o corpo variou de alongado a moderado, a cabeça moderada e o olho de moderado a grande. As distâncias pré-nadadeiras em relação a CP variaram entre 61,5 – 79,2% para CPA; 51,8 – 72,9% para CPD; 10,7 – 29,2% para CPP e 37,8 – 47,2% para CPPV. O CC variou entre 7,9 – 29,2% CP; AC entre 5,7 – 19,2% CP; ACPde 6,3 – 27,1% CP; e DO variou entre 16,7 – 42,9% em relação a CC. O número total de vértebras em A. vaillanti variou de 36 a 39 e de miômeros de 31 a 45. A posição de inserção da nadadeira dorsal variou entre a 14ª e a 18ª vértebra pré-caudal e a da nadadeira anal, entre a 21ª e a 24ª vértebra pré-caudal. A ordem de aparecimento dos primeiros raios das nadadeiras foi D, C, A, V e P. O número definitivo de raios dentre elas, entretanto, é observado na seguinte ordem: D e A no estágio de flexão; e P, V e C no estágio de pós-flexão. Na região do baixo São Francisco, A. vaillanti pode ocorrer simpatricamente com A. lepidentostole, podendo distinguir-se desta espécie pelo menor número de raios da nadadeira dorsal (15-16 versus 12-13 em A. vaillanti), pelo número total de vértebras menos elevado (40 versus 37-40) e pelo maior comprimento pré-peitoral (14-16% CP versus 22,8-28,9% CP).

Primatas apresentam maturação tardia em relação a outros mamíferos, com infância e, particularmente, juventude prolongadas. Duas hipóteses para explicar esta característica da ordem são a hipótese da necessidade de aprendizagem, que aponta a necessidade de aquisição de habilidades sociais ou de forrageamento como fator-chave, e a hipótese de aversão a riscos, segundo a qual primatas apresentam crescimento lento de modo a reduzir suas taxas metabólicas, uma vez que sofrem com a competição por alimento com indivíduos adultos devido à baixa posição hierárquica ou a uma menor eficiência no forrageamento. O presente trabalho analisou o desenvolvimento comportamental de jovens macacos-prego (Sapajus sp.) de um grupo que vive em semi-liberdade no Parque Ecológico do Tietê, São Paulo, de outubro de 2007 a maio de 2010. Os dados foram obtidos com os métodos Focal de Varredura e Todas as Ocorrências. Os resultados mostram uma hierarquia de dominância, de modo geral, herdada da mãe entre as fêmeas e dependente de idade entre os machos. O grande número de indivíduos com pouca participação em interações agonísticas e de díades sem relações de dominância e o baixo número de coalizões, que envolveram principalmente indivíduos dominantes, sugerem um mecanismo de evitação de conflitos por parte dos subordinados. Ao longo do desenvolvimento, houve uma redução na agressão sofrida pelos jovens, sugerindo que esse mecanismo de evitação é aprendido ao longo do desenvolvimento. As relações afiliativas de proximidade e catação dependeram fortemente do parentesco entre os indivíduos e de sua posição hierárquica, sendo que nas relações de proximidade houve também efeito da idade, com jovens mantendo-se próximos entre si. Jovens fêmeas investiram mais na construção e manutenção de redes afiliativas, por meio da catação, do que os jovens machos, e foram mais toleradas. O orçamento de atividades e o comportamento alimentar diferiram entre as categorias etárias, porém houve pouca influência do sexo. Houve evidências de sincronia de atividades entre os jovens e seus vizinhos mais próximos, porém as diferenças na dieta entre jovens e adultos sugerem que a aprendizagem social não foi o principal fator influenciando o comportamento alimentar dos jovens. Sua maior dedicação a recursos de fácil obtenção (frutos) do que a recursos mais difíceis de obter (invertebrados) indica menor eficiência no forrageamento. A menor dedicação a alimentos aprovisionados, por sua vez, sugere desvantagem na competição intra-grupo. O comportamento dos jovens no grupo estudado dá suporte ao modelo de aversão a riscos, embora haja evidências de que a aquisição de habilidades sociais e de forrageamento seja um fator importante no seu desenvolvimento / Primates exhibit delayed maturation in comparison to other mammals, with a long juvenile period. Two attempts to explain this characteristic are the needing to learn hypothesis, which points towards the need to acquire social or foraging skills as important challenges for juveniles, and the juvenile risk aversion hypothesis, according to which primates have slow growth rates in order to reduce metabolic rates, because they have a disadvantage in the competition for resources against adults, due to lower hierarchical position or to less foraging efficiency. The present work analyses the behavioral development of juvenile capuchin monkeys (Sapajus sp) from a semi-freeranging group at Parque Ecológico do Tietê (PET), São Paulo, Brazil, from October 2007 to May 2010. Data was obtained using scan sampling and all occurrences methods. Results show that the dominance hierarchy was mostly inherited from the mother, for juvenile females, and age-related, for males. The large number of individuals with little or no participation in agonistic interactions and of 0x0 ties, and the low number of coalitions, which involved mostly dominant individuals, suggest that a conflict-avoidance mechanism is being used by subordinates. There was a reduction in the aggression suffered by juveniles through time, suggesting that this mechanism is learned throughout the development. Affiliative relationships were highly dependent on kinship and hierarchical position, and in proximity there was also an effect of age, with juveniles close to one another. Juvenile females invested more in building and maintaining social networks, through grooming, than male juveniles, and were more tolerated in proximity. The activity budget and feeding behavior differed among age categories, but there was little influence of sex. There was evidence of synchrony of activities between juveniles and individuals in proximity, but differences in diet between juveniles and adults suggest that social learning was not the main influence on juveniles\' foraging behavior. They allocated more foraging time to resources easy to obtain (fruits) than to more difficult to obtain resources (invertebrates), which indicates they are less efficient in foraging. They also dedicated less time to provisioned food, suggesting a disadvantage in intra-group competition. The behavior of the juveniles observed in this study supports the risk aversion model, although there are evidences that the acquisition of social and foraging skills also plays an important role on their development

O gênero Passiflora é o maior gênero da família Passifloraceae, que compreende mais de 500 espécies, a maioria originária de regiões neotropicais, sendo centenas distribuídas pela América Latina. Algumas dessas espécies apresentam importância econômica na produção de fruta in natura, suco concentrado, uso ornamental e medicinal com propriedades sedativas. Estudos do desenvolvimento reprodutivo e do fruto de espécies de Passiflora são fundamentais para melhor compreensão de aspectos do desenvolvimento que possam contribuir para a produção agronômica e compreensão da evolução de estruturas florais presentes em espécies desta família. A importância das sementes para a sua propagação, para estudos taxonômicos e a presença do arilo, estrutura de interesse fundamental para a comercialização de frutos e produção de suco em espécies desse gênero, estimulou a elaboração de um estudo comparativo entre duas espécies de interesse comercial, P. edulis e P alata, associando o estudo de características morfoanatômicas e moleculares. O presente projeto teve como objetivo caracterizar o desenvolvimento do embrião zigótico e arilo de Passiflora edulis Sims e Passiflora alata Curtis. Flores foram manualmente polinizadas e amostras coletadas periodicamente após a polinização, visando à obtenção de sementes em diferentes fases do desenvolvimento embrionário e do arilo. Primórdios do arilo são observados em pré-antese, quando o saco embrionário é organizado. Células epidérmicas na base do funículo sofrem divisões periclinais formando uma borda em torno da rafe. O desenvolvimento do primórdio do arilo é interrompido, observando-se a reativação de divisões celulares e o arilo recomeça o desenvolvimento em uma estrutura multicelular ao redor da semente em desenvolvimento. Aos 14 dias após a polinização o arilo já cobre dois terços da semente, crescendo rapidamente até a semente ser recoberta totalmente, desde o funículo, até o polo calazal. O endosperma é nuclear e seu desenvolvimento se inicia logo após a fertilização, através de divisões sucessivas, formando um sincício ao redor do proembrião, simultaneamente à diminuição tamanho do nucelo. A celularização do endosperma, com a deposição de paredes celulares é observada aproximadamente 20 dias após a polinização. A embriogênese se inicia com a primeira divisão do zigoto, observada aos 7 dias após a polinização. Essa primeira divisão é transversal dividindo o zigoto em duas células, assimetricamente. A célula apical sofre sucessivas divisões que levam a estádios subsequentes de desenvolvimento do embrião, tais como, 4-8 células, globular, coração e torpedo. Aproximadamente 30 dias após a polinização o embrião atinge o estádio cotiledonar e a partir de então apenas aumenta em tamanho consumindo o endosperma e ocupando seu espaço na semente. Essas observações permitiram que fossem definidos dois estádios específicos do desenvolvimento do arilo para futura captura por microdissecção a laser. A caracterização anatômica do desenvolvimento do embrião e do arilo em ambas as espécies subsidia o estabelecimento de estádios específicos do desenvolvimento que podem servir como alvos para estudos moleculares nessas espécies de Passiflora / Passiflora is the largest genus in Passifloraceae and most of the commercially used species develop an aril around the seed, which is commercially important for fresh fruit consumption, and concentrate juice. Reproductive developmental studies associating morphoanatomical and molecular characteristics are essential for a better understanding of particularities of this genus. The present project aimed to characterize the development of Passiflora edulis Sims and Passiflora alata Curtis zygotic embryo and aril. Pollination of flowers were done manually, fruits and ovaries were collected at regular intervals after pollination and processed for scanning and light microscopy, for analysis of embryos and aril in different stages of development. Aril primordium is observed in pre-anthesis when the embryo sac is organized. Epidermic cells at the base of the funiculus undergo periclinal divisions forming a rim surrounding the raphe. Aril development is arrested until after fertilization when cell divisions are reactivated and the aril resume development into a multicellular structure surrounding the developing seed from the funicle towards the chalazal end. At approximately 14 days after pollination the aril already covers two thirds of the seed, and grows rapidly until the whole seed is covered. The endosperm is nuclear and starts developing soon after fertilization through successive divisions forming a syncytium mostly at the chalazal region, and around the developing embryo, replacing the nucellus. Cell walls are formed and the endosperm begins cellularization approximately 20 days after pollination. Embryogenesis initiates with the first division of the zygote, approximately 7 days after pollination. This first cell division is transversal and asymmetrical; the apical cell undergoes successive divisions leading to the subsequent stages of embryo development such as 4- and 8-celled, globular, heart-shaped, torpedo. Approximately 30 days after pollination, the embryo reaches the cotyledonary stage and thereafter grows only in size, consuming the endosperm and occupying its space in the seed. The first division of the zygote was observed around seven days after pollination (DAP), with the mature embryo formed approximately 30 DAP. Initial development of the aril primordium is observed at the ovule basal region, before anthesis/pollination. Embryo and aril development occurs simultaneously. These observations allowed for the definition of two specific stages of aril development for laser-capture-microdissection and further molecular analysis aiming at the evaluation of the molecular basis of aril differentiation in Passiflora. The morphoanatomical characterization of embryo and aril development in these species will serve as a source of information for the definition of specific developmental stages, which can be targets for molecular studies in Passiflora

Laticifers are poorly known among Sapindaceae species. They have only been cited in few works, without a description of its structure, ontogeny and histochemistry, which is of great importance to classify and distinguish them from idioblasts that are cells usually observed in the same organs. Therefore, this work aimed to verify the presence of laticifers in 64 species belonging to 21 genera of Sapindaceae, and to analyze their anatomical aspects, latex composition and evolution within the family. The material obtained from herbaria was rehydrated and embedded in methacrylate, according to the usual techniques in plant anatomy. For histochemical analysis fresh or Paraplast-embedded shoots were used. The presence of articulated nonanastomosing laticifers was confirmed for 15 genera from two subfamilies, being described for the first time in some genera. Apparently, this secretory structure arose six times during evolution of the family. They originate early in the development of shoot apex when the tissues are still in meristematic phase and distributed generally in cortex, phloem and pith. The histochemical tests allowed the observation of lipids, carbohydrates, proteins, alkaloids, and phenolic compounds in the latex. Callose and suberin was also detected in laticifer walls of some species, helping in the interpretation of the infratribal relationships. In general laticifers in the family are small, short and narrow in comparison with other families, and for this reason, for a long time, remained unrecorded in the literature. Presence or absence of laticifers can be used as a character that can help in taxonomic resolution and establishment of relations among groups within Sapindaceae / Os laticíferos são pouco conhecidos em espécies de Sapindaceae. Eles só foram citados em alguns trabalhos, sem uma descrição da sua estrutura, ontogenia e histoquímica que permita classificá-los e distingui-los dos idioblastos que geralmente são observados nos mesmos órgãos. Portanto, o objetivo deste trabalho foi verificar a presença de laticíferos em 64 espécies pertencentes a 21 gêneros de Sapindaceae e analisar seus aspectos anatômicos, da composição de látex e evolução dentro da família. O material obtido a partir de herbários foi reidratado e incluído em metacrilato de acordo com as técnicas usuais de anatomia vegetal. Para a análise histoquímica foram utilizados ápices frescos e incluídos em Paraplast. A presença de laticíferos articulados não anastomosados foi confirmada para 15 gêneros de duas subfamílias, tendo sido descrita pela primeira vez em alguns destes gêneros. Aparentemente, essa estrutura secretora surgiu seis vezes na família. Eles são originados no início do desenvolvimento no meristema apical quando os tecidos ainda estão na fase meristemática e são distribuídos geralmente no córtex, no floema e na medula. O uso de testes histoquímicos permitiu observar lipídeos, carboidratos, proteínas, alcaloides e compostos fenólicos no látex. Calose e suberina também foram observadas na parede do laticífero de algumas espécies, ajudando na interpretação das relações infratribais. Em geral, os laticíferos da família são pequenos, curtos e estreitos em comparação a outras famílias e, por esse motivo, não se encontram registros na literatura. A presença ou ausência de laticíferos pode ser usada como caráter para ajudar na resolução taxonômica e estabelecimento de relações entre grupos dentro de Sapindaceae

Psychostimulant-induced reinstatement of place preferences have been used to investigate underlying physiological mechanisms mediating drug-seeking behavior in adolescent and adult rodents; however, it is still unclear how psychostimulant exposure during adolescence affects neuronal communication in the mesolimbic dopamine (DA) pathway and whether these changes would elicit enhanced drug-seeking behavior later in adulthood. The aim of the present study was to investigate the effects of intra-ventral tegmental area (VTA) or intra-nucleus accumbens septi (NAcc) DA D2 receptor antagonist infusions on cocaine-induced reinstatement of cocaine place conditioning in high and low responders for cocaine reward. Adolescent rats were exposed to cocaine place conditioning [postnatal day (PND 28-39)] and divided into high and low responders for cocaine reward based on their place preference expression score. Place preferences were extinguished and guide cannula were implanted into either the VTA or NAcc followed by one of the following: 1) intra-VTA or intra-NAcc infusion of the DA D2 receptor antagonist sulpiride (100 µM) during a cocaine-primed reinstatement test (10 mg/kg/ip cocaine) or 2) measurement of NAcc DA levels during intra-VTA or intra-NAcc infusion of sulpiride (100 µM), a cocaine prime (10 mg/kg cocaine) and re-exposure to the cocaine paired chamber. Infusion of sulpiride into the VTA but not the NAcc blocked reinstatement of cocaine place conditioning in rats exposed to cocaine during adolescence. Furthermore, re-exposure to cocaine-associated cues and simultaneous local infusion of sulpiride into either the VTA or NAcc attenuated cocaine-induced increases in accumbal DA levels for rats pretreated with cocaine during adolescence, regardless of phenotype. These data suggest intrinsic compensatory mechanisms in the mesolimbic DA pathway mediate adolescent behavioral responsivity to cocaine prime-induced reinstatement of cocaine place conditioning later on in adulthood.

Ontogenetic patterns in postcranial robusticity are analysed in the skeletons of eighty-two juvenile Later Stone Age hunter-gatherers with estimated ages at death ranging from infancy to late adolescence. Robusticity is quantified from cross-sectional geometric properties of diaphyses at sixteen sites throughout the skeleton, using radiography and casting methods. Skeletal growth profiles for strength measures are analysed with locally-weighted regression and additional curve fitting to evaluate developmental trajectories. Ethnographic accounts of infancy and childhood in modern Ju/'hoansi (Khoesan) communities provide a culturally-relevant interpretive framework for evaluating skeletal correlates of behaviour. This research demonstrates that bone strength properties can be functionally linked to behaviour among juveniles toward the reconstruction of patterns of physical activity among prehistoric children. Postcranial strength measures vary predictably with age such that developmental patterns and timing in appositional growth can be assessed reliably. The onset of walking among Later Stone Age juveniles is evident by two years of age from proportional lower to upper limb strength measures. The lower limb continues to adapt to increasing loading demands especially in response to torsional forces, and bending in the medio-lateral plane; biomechanical shape measures illustrate the gradual development of the femoral pilaster. Individual humeral strength is symmetrical with respect to the orientation maximal bending forces experienced throughout development, but the magnitude of the functional adaptive response is greater, on average, in the right limb with more than 70% of the sample over the age of six displaying right-side dominance. Humeral asymmetry and side dominance does not emerge until late childhood, and the majority of arm strength is accrued during adolescence, relative to the sex-combined mean values for Later Stone Age adults. Evidence for sexual dimorphism in upper limb properties is evident by late adolescence whereas sex-based patterns of mobility reflected in lower limb strength have yet to emerge. These results illustrate the developmental patterns that underlie postcranial markers of subsistence activities in Later Stone Age hunter-gatherers.

In this thesis, I combined field, greenhouse and common-garden experiments to examine the ecological and evolutionary consequences of plant-herbivore interactions and the genetic architecture of fitness-related traits in the insect-pollinated, self-incompatible, perennial herb Arabidopsis lyrata. More specifically, I examined (1) whether damage to leaves and inflorescences affects plant fitness non-additively, (2) whether trichome production is associated with a cost in terms of reduced tolerance to leaf and inflorescence damage, (3) whether young plant resistance to a specialist insect herbivore varies among populations, and (4) whether the evolution of flowering time, floral display and rosette size is constrained by lack of genetic variation or by genetic correlations among traits. A two-year field experiment in a Swedish population showed that damage to rosette leaves and to inflorescences can affect both current and future plant performance of A. lyrata, and that effects on some fitness components are non-additive. A two-year field experiment in another Swedish population indicated that trichome-producing plants are not less tolerant than glabrous plants to leaf and inflorescence damage. In a greenhouse experiment, acceptability of young plants (5-6 weeks old) to ovipositing females and damage received by Plutella xylostella larvae varied considerably among twelve A. lyrata populations. Both oviposition and leaf damage were positively correlated with rosette size, but trichome density in the trichome-producing morph was apparently too low at this developmental stage to influence resistance to P. xylostella. In a common-garden experiment, flowering time, floral display and rosette size varied among four Scandinavian A. lyrata populations, and displayed significant additive genetic variation in some populations. Yet, strong genetic correlations between flowering start and number of flowers, and between petal length and petal width suggest that these traits may not evolve independently. Taken together, the results indicate the need to consider possible long-term and non-additive effects of herbivore damage to different plant parts, that there is no trade-off between trichome production and tolerance to herbivory, that the importance of morphological defenses against herbivory may change through plant ontogeny, and that considerable genetic variation for traits such as flowering time and floral display can be maintained in natural plant populations.

Ontogenetic patterns in postcranial robusticity are analysed in the skeletons of eighty-two juvenile Later Stone Age hunter-gatherers with estimated ages at death ranging from infancy to late adolescence. Robusticity is quantified from cross-sectional geometric properties of diaphyses at sixteen sites throughout the skeleton, using radiography and casting methods. Skeletal growth profiles for strength measures are analysed with locally-weighted regression and additional curve fitting to evaluate developmental trajectories. Ethnographic accounts of infancy and childhood in modern Ju/'hoansi (Khoesan) communities provide a culturally-relevant interpretive framework for evaluating skeletal correlates of behaviour. This research demonstrates that bone strength properties can be functionally linked to behaviour among juveniles toward the reconstruction of patterns of physical activity among prehistoric children. Postcranial strength measures vary predictably with age such that developmental patterns and timing in appositional growth can be assessed reliably. The onset of walking among Later Stone Age juveniles is evident by two years of age from proportional lower to upper limb strength measures. The lower limb continues to adapt to increasing loading demands especially in response to torsional forces, and bending in the medio-lateral plane; biomechanical shape measures illustrate the gradual development of the femoral pilaster. Individual humeral strength is symmetrical with respect to the orientation maximal bending forces experienced throughout development, but the magnitude of the functional adaptive response is greater, on average, in the right limb with more than 70% of the sample over the age of six displaying right-side dominance. Humeral asymmetry and side dominance does not emerge until late childhood, and the majority of arm strength is accrued during adolescence, relative to the sex-combined mean values for Later Stone Age adults. Evidence for sexual dimorphism in upper limb properties is evident by late adolescence whereas sex-based patterns of mobility reflected in lower limb strength have yet to emerge. These results illustrate the developmental patterns that underlie postcranial markers of subsistence activities in Later Stone Age hunter-gatherers.

<p>The pace of life history is highly variable across mammals, and several evolutionary biologists have theorized that the tempo of a species' life history is set by external factors. These factors, such as food availability and predation pressure, determine mortality rates. In turn, mortality rate determines the age at maturity. High mortality rate results in early age at maturity; individuals must grow and reproduce quickly because of the high risk of death. Conversely, a low mortality rate is allows individuals to prolong their growth period and reproduce slowly. This theory assumes that growth rates are constant across species, and thus body size is determined by mortality rates.</p><p>This project posits that the intrinsic characteristics of species set the pace of life history. Among anthropoids, there is a great deal of variation in growth rates and the pace of life history relative to body size. The hypotheses proposed by this project state that the degree of encephalization in a species determines the growth rates, the length of the growth period, and the adult lifespan. Growing a large brain is costly and requires a prolonged period of development. However, a large brain has the benefit of reducing mortality by facilitating cognitive strategies for food procurement and predator avoidance. This cost/benefit balance results in the pattern of life-history variation in which mortality rates are correlated with the length of the growth period. However, the causal arrows are reversed; instead of the mortality rate determining the age at maturity and consequently the size of the species, the relative brain size of the anthropoid determines the mortality rate and the age maturity.</p><p>These hypotheses were tested by determining the body and brain growth trajectories of thirteen anthropoids, and compiling life-history data from long-term studies of these species in the wild. Multi-variate analyses demonstrated that extensive brain growth, whether through prolonged duration or rapid growth rates, results in slow body-growth rates during the juvenile period and delayed age at maturity. In addition, encephalization results in longer adult lifespan. Therefore, this project demonstrated that intrinsic characteristics of anthropoid species determine the pace of their life histories.</p> / Dissertation