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This thesis puts forward a computational framework that can be used by embodied artificial agents (and in particular autonomous robots) for ontogenetic development. The research investigates methods, endowed with which, an embodied agent can develop control structures for increasingly complex and better adapted behaviour, explicitly and incrementally from its history of interaction with its environment. The temporal horizon of an agent is extended so that past experience can be self-organized into a developing structure that can be used to anticipate the future and act appropriately in environments where state information is incomplete, such as a social environment. A formal definition of sensorimotor experience is given, and Crutchfield’s information metric is used as the basis for comparison of experiences. Information metrics are demonstrated to be able to characterize and identify time-extended behaviour. A definition of a metric space of experiences is followed by the introduction of an architecture that combines this with environmental reinforcement as the basis for a system for robot ontogeny. The architecture is demonstrated and tested in various robotic and simulation experiments. This thesis also introduces the early communication game “Peekaboo” as a tool for the study of human-robot interaction and development. The interaction history architecture is then used by two different robots to develop the capability to engage in the peekaboo game.

Thesis advisor: Elizabeth A. Kensinger / Neural and behavioral responses to emotional stimuli often are discussed within an evolutionary framework. Although some of the information that elicits an emotional response is likely to have had evolutionary significance (e.g., snakes, spiders), many other stimuli would not have been evolutionarily relevant (e.g., guns, grenades). The present study re-analyzed data from two fMRI studies (Kensinger et al., 2007; Kensinger & Schacter, 2008) to examine whether the neural systems that respond to emotional stimuli differ depending upon whether those stimuli were of phylogenetic or ontogenetic significance. The results revealed that when stimuli were ontogenetic, activity was increased in regions of the anterior cingulate and orbitofrontal cortices. By contrast, when stimuli were phylogenetic, activity was increased in a region spanning the lingual and fusiform gyri. These results suggest that there can be differences in how emotional stimuli are processed, and those differences can depend upon the stimuli’s evolutionary significance. / Thesis (BA) — Boston College, 2009. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: Psychology Honors Program. / Discipline: Psychology.

Doctor of Philosophy / Division of Biology / Keith B. Gido / This dissertation consists of three research-based chapters which focus on habitat association of prairie stream fishes and how these fish communities influence stream ecosystem properties. Chapter one introduces important concepts used throughout the chapters, and describes my study streams. In chapter two, I identify local habitat factors associated with the diversity and density of fishes in two protected prairie watersheds. Specifically, the relative importance of habitat factors associated with fish communities were evaluated along a stream-size gradient and across multiple seasons and years. I found that species richness was positively associated with pool area and discharge. Redundancy analyses showed common prairie fish species exhibit ontogenetic habitat associations, with adults in deep and juveniles in shallow pools. Chapter 3 addresses how fish species richness in small prairie streams affects whole-stream metabolism and biomass distribution of benthic organic matter, algal and macroinvertebrates. This study was conducted by stocking experimental stream mesocosms that included pool-riffle habitats with three different communities that represent a gradient of species richness of headwater prairie streams from one to three common prairie stream fish species. I illustrated how species influence ecosystems across multiple spatial scales and found that different communities altered the distribution of algal biomass from benthic surfaces to floating mats and from pools to riffles. The objective of the fourth chapter was to quantify how two size classes of herbivorous prairie stream fish species, central stoneroller Campostoma anamolum and southern redbelly dace Chrosomus erythrogaster differentially affect stream ecosystem properties. This study was also conducted in experimental stream mesocosms, where each unit consisted of one riffle and one pool. Using ANOVAs, I found large dace were associated with longer filaments (F = 7.5, P = 0.002, df = 4) and small fishes with less benthic organic matter (F = 4.2, P = 0.02, df = 4). There was no evidence for ontogenetic shifts in diet and likely differences in energetic requirements and behavior drove the differences among treatments. My research finds that small-bodied prairie stream fishes have predictable habitat preferences and effects on stream properties are dependent on species identity, richness and size structure.

The green python Morelia viridis is a most striking animal. Individuals are born either brick red or bright yellow and both colours change to green as adults. These colours and the remarkable colour change have long made them of interest to biologists and in demand for the pet trade. Despite this interest nothing is known of their distribution, biology or ecology in the wild. Here I address this knowledge gap by presenting results from the first detailed study of the species, at Iron Range on eastern Cape York Peninsula, Australia.¶ Individual growth was described by the von Bertalanffy growth curve, with a maximum predicted size of 1.35 metres snout-vent length. Males matured at 2.4 years and females at 3.6 years, and growth was indeterminate after approximately 12 years. The colour change from yellow to green occurs at 55 centimetres, which corresponds to individuals approximately a year old. There was no sexual dimorphism in adults, however juvenile females had larger heads than juvenile males. Adult sized individuals comprised ~50% of the population.¶ Females had a home range of 6.2 ± 1.9 ha (mean ± SE), which was positively correlated with their snout-vent length. Males adopted a roaming strategy through suitable habitat while juveniles were restricted to areas where more light reached the ground. There was overlap between multiple female home ranges, and between female home ranges and the movement paths of males. There were no differences in the distances moved by males and females of any size, although the variation in movement distances was greater in the dry season than the wet season.¶ Green pythons are obligate ambush predators which eat a variety of prey. They show an ontogenetic shift from invertebrates and terrestrial, diurnal reptiles to birds and terrestrial, nocturnal mammals. This diet change is concurrent with a shift in the time of hunting, and the location and characteristics of ambush sites. Yellow individuals were usually found within ten metres of the ground, while green individuals used the full vegetation strata and were often found in the canopy.¶ The three colour morphs of the green python appear to be adaptive for camouflage rather than intraspecific communication, as conspicuousness of each morph was always greater to a predator than to that of a conspecific. Using advanced light analysis techniques I show that each colour morph is adaptive for camouflage from visually orientated avian predators under different environmental conditions. Yellow and red morphs are half as conspicuous as green individuals would be in locations near the ground where juveniles hunt during the day. Green was the least conspicuous morph in only the canopy, where it was half as conspicuous as either the red or yellow morph. In both leafy and non-leafy sub-canopy environments green individuals were more conspicuous than both yellow and red morphs. Red morphs were least conspicuous in only the non-leafy sub-canopy environment. The conspicuousness of green males decreased with age, but this was not the case with green females. Predation of plasticine models of the three colour morphs showed that red models were ten times more likely to be predated than either green or yellow morphs, however the model colours did not always match the real morph colours.¶ There is a large predicted global distribution in Papua New Guinea, including some offshore islands, however the Australian range is restricted to small areas of eastern Cape York Peninsula. In Australia green pythons occurred in nine regional ecosystems, with most records for the closed semi-deciduous mesophyll vine forest ecosystem. A mark-recapture study at Iron Range captured 101 individuals 147 times over two wet seasons, which equates to a population size of 227 ± 81 individuals in the study area of 51 hectares. Based on the known population structure at this site only 114 (or 50%) of these individuals are adult. Although green pythons have a high density at the one intensely studied site and are predicted to occur over a large geographic area, my data are insufficient to conclude that the species is not vulnerable.

The green turtle, Chelonia mydas, is a circumglobal species that exhibits several important developmental or ontogenetic shifts throughout its life history. The first major shift occurs when juvenile turtles migrate from pelagic habitat, where they forage as omnivores, to coastal neritic habitat, where they become primarily herbivores, foraging on algae and seagrass. Anecdotal evidence and gut-content analyses suggest that juvenile green turtles in south Texas bays, such as the lower Laguna Madre and Aransas Bay, undergo an additional ontogenetic shift during this important life history stage. Evidence from stable isotope analysis (SIA) of scute tissues of green turtles from Texas' lower Laguna Madre and Aransas Bay supports an intermediate stage between this species' shift from pelagic waters to seagrass beds in neritic waters; this additional shift comprises an initial recruitment of post-pelagic juveniles to jetty habitat located on the channel passes Gulf-ward of adjacent bays before subsequently recruiting to seagrass beds in these bays. Examination of stable carbon ([delta]¹³C) and nitrogen ([delta]¹⁵N) isotopes in microlayers of scute tissue from several size classes of green turtles from the lower Laguna Madre and Aransas Bay was used to confirm the occurrence of two ontogenetic shifts. Smaller green turtles (< 35 cm SCL) exhibited more depleted [delta]¹³C signatures and more enriched [delta]¹⁵N signatures, consistent with jetty habitat, compared to those of larger counterparts (> 45 cm SCL) that displayed enriched [delta]¹³C signatures and depleted ¹⁵N signatures, consistent with seagrass habitat. Changes in the isotopic composition between these size classes indicate distinct shifts in diet. Post-pelagic juveniles first recruit to jetty habitat and forage primarily on algae, before subsequently shifting to seagrass beds and foraging primarily on seagrass. These findings indicate the use of a characteristic sequence of distinct habitats by multiple life history stages of green turtles in Texas bays, a conclusion with broad management implications for this endangered species.

Resumo: O veneno da serpente Crotalus durissus terrificus (C.d.t.) é constituído pelas toxinas: Crotoxina, Crotamina, Giroxina e Convulxina. A crotamina possui ação miotóxica, sendo que esta toxina pode ser expressa ou não por animais de uma mesma região. Variações bioquímicas, enzimáticas e farmacológicas dos venenos, podem estar associadas a fatores geográficos, clima, sexo, idade, dieta, bem como tempo decorrido de cativeiro e entre extrações. Esta pesquisa teve como objetivo caracterizar o veneno de C.d.t, da micro-região de Botucatu (São Paulo) pela determinação de suas propriedades bioquímicas, farmacológicas e enzimáticas. Para isto, foi realizada a comparação de venenos de serpentes recém capturadas da natureza com o de cativeiro, para verificar a influência da variação sexual, ambiental (tempo de cativeiro) e ontogenética na sua composição. Foram utilizadas técnicas de dosagem protéica, eletroforese (SDS-PAGE), perfil cromatográfico (HPLC-RP), atividade coagulante e índice de coagulação, atividade proteolítica sobre a caseína, tóxica(DL50) e atividade da crotamina. As atividades das 93 amostras de veneno foram comparadas com as do Veneno Referência Nacional. A dosagem protéica não evidenciou variação entre os grupos formados por adultos (75%), mas mostrou diferença quando comparada a do grupo de filhotes (60%). A análise eletroforética (SDS-PAGE 15%) evidenciou que a variação da presença da crotamina não teve relação com a distribuição dos grupos, sendo que 65% das amostras foram crotaminanegativa. O perfil cromatográfico corroborou os resultados da eletroforese, a respeito da variação da crotamina, mostrando grandes variações nas concentrações das proteínas, além de evidenciar grande quantidade de isoformas de crotoxina. Na caracterização coagulante dos venenos, não houve variação entre os grupos formados por adultos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Crotalus durissus terrificus (C.d.t.) venom is composed by the following toxins: crotoxin, crotamine, gyroxin and convulxin. Crotamine possess a myotoxic action that can be expressed or not by snakes from the same region. Biochemical, enzymatic and pharmacological variations of venoms may be associated with geographic factors, climate, gender, age, and diet as well as length of captivity and venom extractions. The present study was carried out in order to characterize the C.d.t. venom of Botucatu micro-region, São Paulo State, by defining its biochemical, pharmacological and enzymatic properties. A comparative characterization of venoms from newly captured snakes and already-captured animals was performed to verify the sexual, environmental (length of captivity) and ontogenetic variations that influence the venom composition. Protein concentration, electrophoresis (SDS-PAGE), chromatographic profile (RPHPLC), coagulant activity and coagulation index, proteolytic activity upon casein, toxic (LD50) and crotamine activity were employed. The venom activities of 93 samples were compared with the National Reference Venom. Protein concentrations did not evidence a variation among the groups of adults (75%), but revealed some difference when compared with newborn groups (60%). The electrophoresis analysis (SDS-PAGE 15%) presented a crotamine variation that had no relation with the distribution of groups, which showed that 65% of the samples were crotamine negative. The chromatographic profile confirmed the results of electrophoresis regarding crotamine variation, and also showed great variation in the protein concentration, besides revealing a high quantity of crotoxin isoforms. Concerning coagulant characterization, there was no variation among adult groups; however, the National Reference Venom and newborn groups presented higher coagulant activities. Toxic (LD 50) and proteolytic activicties... (Complete abstract click electronic access below) / Orientador: Rui Seabra Ferreira Junior / Coorientador: Andreimar Martins Soares / Banca: Daniel Carvalho Pimenta / Banca: Patrick Kack Spencer / Mestre

Made available in DSpace on 2014-06-11T19:24:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-28Bitstream added on 2014-06-13T19:51:39Z : No. of bitstreams: 1 lourencojunior_a_me_botfm.pdf: 1329256 bytes, checksum: 4e8b2e54b89603c559c64dfee4a7c8a2 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O veneno da serpente Crotalus durissus terrificus (C.d.t.) é constituído pelas toxinas: Crotoxina, Crotamina, Giroxina e Convulxina. A crotamina possui ação miotóxica, sendo que esta toxina pode ser expressa ou não por animais de uma mesma região. Variações bioquímicas, enzimáticas e farmacológicas dos venenos, podem estar associadas a fatores geográficos, clima, sexo, idade, dieta, bem como tempo decorrido de cativeiro e entre extrações. Esta pesquisa teve como objetivo caracterizar o veneno de C.d.t, da micro-região de Botucatu (São Paulo) pela determinação de suas propriedades bioquímicas, farmacológicas e enzimáticas. Para isto, foi realizada a comparação de venenos de serpentes recém capturadas da natureza com o de cativeiro, para verificar a influência da variação sexual, ambiental (tempo de cativeiro) e ontogenética na sua composição. Foram utilizadas técnicas de dosagem protéica, eletroforese (SDS-PAGE), perfil cromatográfico (HPLC-RP), atividade coagulante e índice de coagulação, atividade proteolítica sobre a caseína, tóxica(DL50) e atividade da crotamina. As atividades das 93 amostras de veneno foram comparadas com as do Veneno Referência Nacional. A dosagem protéica não evidenciou variação entre os grupos formados por adultos (75%), mas mostrou diferença quando comparada a do grupo de filhotes (60%). A análise eletroforética (SDS-PAGE 15%) evidenciou que a variação da presença da crotamina não teve relação com a distribuição dos grupos, sendo que 65% das amostras foram crotaminanegativa. O perfil cromatográfico corroborou os resultados da eletroforese, a respeito da variação da crotamina, mostrando grandes variações nas concentrações das proteínas, além de evidenciar grande quantidade de isoformas de crotoxina. Na caracterização coagulante dos venenos, não houve variação entre os grupos formados por adultos... / Crotalus durissus terrificus (C.d.t.) venom is composed by the following toxins: crotoxin, crotamine, gyroxin and convulxin. Crotamine possess a myotoxic action that can be expressed or not by snakes from the same region. Biochemical, enzymatic and pharmacological variations of venoms may be associated with geographic factors, climate, gender, age, and diet as well as length of captivity and venom extractions. The present study was carried out in order to characterize the C.d.t. venom of Botucatu micro-region, São Paulo State, by defining its biochemical, pharmacological and enzymatic properties. A comparative characterization of venoms from newly captured snakes and already-captured animals was performed to verify the sexual, environmental (length of captivity) and ontogenetic variations that influence the venom composition. Protein concentration, electrophoresis (SDS-PAGE), chromatographic profile (RPHPLC), coagulant activity and coagulation index, proteolytic activity upon casein, toxic (LD50) and crotamine activity were employed. The venom activities of 93 samples were compared with the National Reference Venom. Protein concentrations did not evidence a variation among the groups of adults (75%), but revealed some difference when compared with newborn groups (60%). The electrophoresis analysis (SDS-PAGE 15%) presented a crotamine variation that had no relation with the distribution of groups, which showed that 65% of the samples were crotamine negative. The chromatographic profile confirmed the results of electrophoresis regarding crotamine variation, and also showed great variation in the protein concentration, besides revealing a high quantity of crotoxin isoforms. Concerning coagulant characterization, there was no variation among adult groups; however, the National Reference Venom and newborn groups presented higher coagulant activities. Toxic (LD 50) and proteolytic activicties... (Complete abstract click electronic access below)

Despite the restricted morphology and distribution of sloths today, fossils sloths show a wide variety of forms and behaviors and used to range from South America to Alaska. These extinct forms have in the past simply been lumped together as "ground sloths", separated from modern "tree sloths". However there are intermediate forms that have been posited to be semi-arboreal. In other groups such as primates the shape of the shoulder blade has been shown to vary significantly between groups with different arboreal behaviors. This study used geometric morphometrics to examine the scapulae of modern and extinct sloths to show that these three locomotor groups can in fact be distinguished by their shoulder blade shape. Juveniles of giant ground sloths also have significantly different shoulder blade shapes than the much larger adults, however they do not overlap with the smaller intermediate sloths, so may have been just as terrestrial as their parents despite their much smaller size. Finally, ontogenetic trajectories of several sloth genera do not show evidence of having different slopes. They start and end in different areas of morhospace but are all on parallel paths. This argues against the hypothesis of convergence in modern tree sloths, which despite both having an unusual suspensory lifestyle are not closely related. Rather they are both retaining an ancestral growth trajectory that all sloths have possessed.

Climate change is causing water temperature to rise, and many lakes in the boreal zone will experience browning of waters (brownification) due to increased input of dissolved organic carbon (DOC). In fish, warming may cause resource limitation and decrease both fish size and population abundance. Many fish species display ontogenetic niche shifts during their lifetime, shifting to larger prey as they grow. Brownification may change the timing for, the benefits from or prevent individuals from displaying ontogenetic niche shifts by decreasing large prey abundance in the benthic zone or making fast-moving prey harder to see. This can cause resource limitations, suppressing growth and population growth. This study investigated the effects of increasing DOC and water temperature on ontogenetic diet shifts, size structure, and population abundance in nine-spine stickleback (Pungitius pungitius) in an experimental pond system with a warming treatment and a gradient of DOC concentration. Warming had a negative effect on population number, biomass, maximum fish size, stomach fullness, and consumption of large prey. Contrary to expected outcomes, increasing DOC input resulted in higher population, biomass, and larger maximum sized fish as DOC increased. DOC did not negatively affect ontogenetic diet shifts. In the relatively shallow enclosures, the highest DOC concentration may not have reached the threshold where the shading effect of DOC overturns the benefits of extra nutrients associated with DOC. Hence, in shallow lake ecosystems, climate change induced DOC increase may support fish production, while warming may have strong negative effects on fish population abundance and size.