Thesis (Ph.D.)--McMaster University, 2004. / Advisor: James Dowling. Includes bibliographical references.

Deep-sea systems are understudied compared to any other ecological system on Earth, but they are important for ecosystem functioning and services. The deep sea is important in the climatic regulation of Earth, and it is a new frontier for resource provisioning for humanity. Impacts, such as increased carbon emissions and deep-sea fishing and mining will likely influence the system, but these effects are not well understood. To recognise these impacts, common patterns in community structure need to be understood. This study aims to assess community structure in the deep sea by looking at patterns in body size and biodiversity. It uses polychaetes (bristle worms) as a study group as they are the most abundant group in the benthic macrofauna in terms of density and play key roles in the food web. Body size is an important component of the community structure, as body size is correlated with many other traits of the organism, from physiological rates (e.g. heart or breathing rates) to population dynamics (e.g. production rates or population abundances) and species richness. It is thought that body size of deep-sea (endo)benthic organisms declines with increasing depth, which is often related to food availability which itself declines with increasing depth. Many contradictory results on body-size change with increasing depth, however, have been reported, including no change, increasing, or a parabolic relationship. It is demonstrated here (Chapter 2) that there is much variety in body-size estimates between different geographic regions and taxonomic groups. These differences can ultimately influence the predictions of other traits, and might hint at what might happen in changing climatic conditions. It sets the basis to argue that there should be a focus on explaining why there are differences, instead of focusing on finding a general trend for organisms in all geographical regions. Furthermore, it is unlikely that food availability alone can explain a change in body size. An alternative explanation is offered (Chapter 3), where habitat complexity is shown to influence body size. Sponge density, in the form of habitat complexity, can have a structuring effect on the community potentially through the loss of spicules that add complexity to soft-sediments, and this in turn can influence body size of organisms. Deep-sea community structure in terms of family richness has been studied at local spatial scale. Fewer studies have been performed on regional spatial scale and these studies lack extensive sampling coverage of environmental gradients. Here (Chapter 4), the first study is presented on the maintenance of deep-sea family composition on regional scale with high sampling coverage along a variety of environmental gradients. It is shown that energy (food) availability, habitat complexity, and long-term temperature are important in influencing the polychaete distribution in this region. It is shown that there is an unusual high proportion of an opportunistic group, the Capitellidae, present in the study area. Biodiversity is important for the maintenance of ecosystem functioning, but human impacts result in the restructuring of biodiversity. The first deep-sea biodiversity - ecosystem functioning relationship for macrofauna is presented (Chapter 5). It is shown that there is a positive and saturating relationship between biodiversity and ecosystem functioning. However, fishing intensity seems to influence this relationship by potentially affecting secondary biomass production, abundance and taxonomic and functional diversity measures. It is suggested that as the disturbance of fishing negatively impacts taxonomic and functional evenness, a system is created where opportunistic species are dominant, like communities found in disturbed areas such as under fish farms. This will have consequences for the state of the system and energy transfer to trophic levels higher up.

The woodlice, Porcellio scaber (Latreille, 1804), is a terrestrial isopod. Its metabolic reserves and body size are important factors affecting the fitness attributes, such as survival at unfavourable conditions. The larger and heavier individuals did not survive longer than smaller individuals. Amount of glycogen and body weight (fresh and dry) appeared to be an inapplicable parameter in the observed differences among individuals during survival at low temperature. We compared three treatments (long day, short day, natural autumn conditions) of Porcellio scaber and found differences in amount of energy reserves and cryoprotectants.

Thesis advisor: Christopher Kenaley / Bergmann’s rule predicts a change in body size with latitude, with larger members of a taxonomic group occurring further from the equator. This pattern has been described for many groups of organisms; however, no study has assessed this relationship across a substantial number of ray-finned fish species, the largest group of vertebrates. I performed Bayesian phylogenetic modeling using maximum length and latitude data for 3021 species of actinopterygians to assess Bergmann’s rule in the group. The impact of salinity tolerance on the relationship between length and latitude was also considered. Maximum length and salinity tolerance data were obtained from FishBase, and latitude data were obtained from museum records. I found that, overall, Bergmann’s rule holds and is not significantly affected by salinity tolerance except when not considering phylogeny, in which case only marine species show the trend. / Thesis (BA) — Boston College, 2023. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Biology.

Dinosaurs are the largest animals to ever walk on the continents and some reached body sizes of up to 70 tons. Observation of their closest living relatives, birds and crocodylians, could never allow for prediction of gigantic dinosaurian forms. Therefore, the fossil record is crucial to understanding the evolutionary changes of these animals through time, including body size trends. The reptile group Archosauria encompasses living and extinct birds and crocodylians as well as non-avian dinosaurs and crocodile relatives called pseudosuchians. My research focuses on studying fossils of extinct archosaurs to determine how the morphology of their skeletons allowed for growth to large body sizes. I am specifically interested in how the vertebral column fits together and how the structures that articulate vertebrae change throughout the phylogeny (i.e. family tree) of Archosauria. Although major body size trends are well known for archosaurs, less research has focused on skeletal features that are associated with the evolution of large body size in that group. I hypothesize that the vertebral column will have these features. To answer the question of how vertebrae morphology is related to body size, I first described eight vertebrae from a large pseudosuchian archosaur Poposaurus langstoni. This animal possesses an accessory articulation between the vertebrae in its trunk region (i.e. between the neck and hips) called the hyposphene-hypantrum articulation. I then surveyed vertebrae from across Archosauria and found a close fit of presence of the articulation with large sizes and that it evolves independently in several archosaur groups. / Master of Science

In this diploma thesis has been tested potential of maternal influences on body growth at two model groups of geckos with large interspecific body size variability. The effect of egg manipulation to hatchling size was proved to be significant for hatchlings at both model species Paroedura picta and Goniurosaurus lichtenfelderi. However, in adult animals, there were no more significant body size differences caused by egg manipulation. It leads to conclusion that both species of geckos have compensatory growth and its adult size is likely to be primarily genetically determined. Key words: maternal effect, egg manipulation, body growth, allometric engeneering, Paroedura picta, Goniurosaurus lichtenfelderi

In ectothermic vertebrates, body segmentation is often linked to final body length. This thesis focuses on the realtionship between final body length, ecological (temperature) and genetic (sex) factors and the count of body vertebrae in the Paroedura geckos, closely focusing on the Paroedura picta species. Individuals of this species were exposed to three different constant rearing temperatures, where they achieved different final sizes. We tested the correlation between the number of presacral vertebrae and final body size and the effect of rearing temperature and sex on the vertebrae number. The data point to high genetic and enviromental canalisation of the vertebrae count. Large conservation in the number of presacral vertebae were found even across the genus Paroedura regardless of the considerable evolutionary changes in body size. Powered by TCPDF (www.tcpdf.org)

The effects of intrinsic traits on the diversification dynamics have been extensively investigated, with several traits being associated with increase in diversification. On the other hand, the possible negative effects of traits on the diversification of a lineage have been for the most part overlooked. Here we used both the fossil record and molecular data to study the diversification dynamics of Placentalia, focusing on the orders in decline of diversity, and investigated different mechanisms that might control the evolutionary success of the 21 placental orders. More specifically we: 1- determined which of the 21 orders of Placentalia are in decline of diversity (i.e., Decline model); 2- investigated whether the Decline model has a phylogenetic signal; 3- tested the hypothesis that the differences in body size are related to the Decline model; 4- tested the hypothesis that the orders in Decline have lower morphological disparity; 5- investigated whether the orders in decline of diversity, inferred from the fossil record, are the ones with higher extinction risk nowadays. Our analysis indicate that the majority of the orders of placental mammals have a pattern consistent with the Decline model and, although the Decline model is not equally distributed among the placental superorders, there was no significant phylogenetic signal for the orders in diversity decline. We found a positive correlation between the Decline model and the average body size which is in line with previous studies on body size evolution. We argue that such results suggest a complex evolutionary dynamics: larger body size appears to be an evolutionary attractor with lineages showing a tendency to increase in size, however, the increase in body size would be counterbalanced by a higher propensity to Decline. Moreover, we found a the negative correlation between the Decline model and morphological variation. We suggest that such results could indicate two possible scenario: (i) the low morphological variation would cause lineages to loose diversity; (ii) the low morphological variation would be the product of decrease in diversity through extinction selectivity. Finally, we found no correlation between the extinction risk of extant species and the deep time diversity decline, which suggests that the drivers of the current and the past Decline are not the same / O efeito de caracteres intrínsecos na dinâmica de diversificação foram extensamente investigados e diversos caracteres foram associados com aumentos na diversificação. Contudo, os possíveis efeitos negativos de um caractere sobre a diversificação de uma linhagem foram em grande parte ignorados. No presente trabalho integramos o registro fóssil com dados moleculares para estudar a dinâmica de diversificação de Placentalia, focando nas ordens em declínio de diversidade, e investigamos possíveis mecanismos responsáveis por gerar os padrões de diversificação encontrados. Mais especificamente nós: 1- determinamos quais das 21 ordens de Placentalia estão em declínio de diversidade (i.e., Declínio); 2- investigamos se o Declínio apresenta um sinal filogenético; 3- testamos a hipótese de que o tamanho do corpo está relacionado com o Declínio; 4- testamos a hipótese de que as ordens em Declínio possum menor disparidade morfológica; 5- investigamos se as ordens em Declínio, inferido a partir do registro fóssil, são as mesas com maior risco de extinção na atualidade. Nossas análises indicam que a maioria das ordens de mamíferos placentários apresentam um signal consistente com o Declínio e, embora o Declínio não esteja igualmente distribuído entre as superorderns de Placentalia, não há um signal filogenético significativo para as ordens em Declínio. Nossos resultados indicam uma correlação positiva entre o Declínio e o tamanho corporal médio de cada ordem que está de acordo com estudos prévios sobre evolução do tamanho do corpo. Argumentamos que estes resultados sugerem uma dinâmica de evolução complexa: tamanho corpóreo grande seria um atrator evolutivo que gera a tendência das linhagens aumentarem de tamanho, todavia, o aumento do tamanho do corpo seria contrabalançado pela maior susceptibilidade ao Declínio. Outrossim, encontramos uma correlação negativa entre o Declínio e a variação morfológica. Argumentamos que essa correlação poderia indicar dois possíveis cenários: (i) a baixa variação morfológica seria responsável pela redução no número de linhagens e tornaria as ordens mais susceptíveis ao declínio de diversidade; (ii) a baixa variação morfológica teria sido gerada pela diminuição da diversidade. Por último, o risco de extinção das espécies atuais não está correlacionado com o Declínio, o que sugere que os mecanismos responsáveis pelo Declínio no passado e no presente não são os mesmos.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A histÃria de vida de um organismo envolve a interaÃÃo entre manutenÃÃo, crescimento e reproduÃÃo. Essa teoria se propÃe a explicar as variaÃÃes nos aspectos populacionais de uma espÃcie em funÃÃo das condiÃÃes e recursos disponÃveis no ambiente, sendo a base teÃrica para estudos relativos à dependÃncia de densidade. A densidade à um fator regulador da dinÃmica populacional por promover competiÃÃo. O presente estudo se propÃe a responder a seguinte questÃo: a densidade influencia o tamanho, a maturidade sexual e a proporÃÃo sexual em uma populaÃÃo do caranguejo Goniopsis cruentata?As condiÃÃes ambientais influenciam os aspectos biolÃgicos e potencializam os efeitos da densidade nesta espÃcie? ExpediÃÃes de campo foram conduzidas, mensalmente, de janeiro a novembro de 2011, nos municÃpios de Aracati e Fortim, CearÃ, Brasil. Os animais foram coletados manualmente em duas estaÃÃes de coleta, Alfredo (A) e Caldeleiro (C), em uma Ãrea de 400m para cada estaÃÃo, durante 40 minutos. Os indivÃduos foram sexados e mensurados quanto a sua largura de carapaÃa, comprimento do gonÃpodo nos machos e largura do abdÃmen nas fÃmeas. Dez indivÃduos de cada estaÃÃo foram submetidos a processamento histolÃgico para determinaÃÃo do estÃgio de desenvolvimento gonadal. A densidade foi calculada pelo nÃmero de indivÃduos por Ãrea (ind/mÂ) e correlacionada aos fatores abiÃticos: pluviosidade, pH e salinidade do solo. Os espÃcimes foram distribuÃdos em classes de tamanho, por estaÃÃo e por sexo. TambÃm foram calculadas a razÃo sexual e as maturidades morfolÃgica e fisiolÃgica. Os fatores abiÃticos de pluviosidade, pH e salinidade do solo foram mensurados e correlacionados à densidade de cada estaÃÃo. A densidade da estaÃÃo A foi maior que a da estaÃÃo C, o que pode ocorrer em funÃÃo da maior disponibilizaÃÃo de nutrientes nesta Ãrea, devido ao pH mais baixo que a estaÃÃo C. A pluviosidade se correlacionou com a densidade em C, devido a esta estaÃÃo apresentar topografia menos elevada, sofrendo maior influencia do nÃvel de Ãgua do rio. A salinidade do solo nÃo apresentou diferenÃas entre as estaÃÃes. O tamanho mÃdio entre machos nÃo variou entre as estaÃÃes, ao contrÃrio do que ocorreu em fÃmeas, com tamanho mÃdio maior na estaÃÃo com mais densa. Em ambos os sexos, os tamanhos mÃximos maiores foram observados na estaÃÃo com maior densidade, indicando menor mortalidade entre adultos e, assim, possibilitando retardo da maturidade nesta estaÃÃo. A distribuiÃÃo em classes de tamanho nÃo divergiu entre as estaÃÃes, mas apresentou uma tendÃncia a ser bimodal na estaÃÃo com maior densidade e unimodal na estaÃÃo com densidade menor. Esse resultado pode indicar influÃncia da densidade na distribuiÃÃo em classes de tamanho. A maturidade sexual foi antecipada na estaÃÃo com densidade menor e retardada na estaÃÃo com densidade maior, como previsto pela teoria de histÃria de vida. Essa tÃtica pode ser resultado de taxas de mortalidade maiores entre juvenis na estaÃÃo mais densa e maiores entre adultos na estaÃÃo menos densa. A proporÃÃo sexual nÃo diferiu entre as estaÃÃes, mas houve tendÃncia de maior proporÃÃo de machos na Ãrea com maior densidade, o que pode acarretar em maior competiÃÃo entre machos pelas fÃmeas. A maior proporÃÃo de fÃmeas observada na Ãrea de densidade menor pode proporcionar uma limitaÃÃo espermÃtica. Os resultados obtidos para o caranguejo Goniopsis cruentata no presente estudo corroboram as previsÃes da teoria de histÃria de vida: (1) em populaÃÃes com densidade menor, a maturidade sexual à antecipada e os organismos alcanÃam tamanhos menores, e em densidade maior a maturidade à retardada com organismos atingindo tamanhos maiores; (2) A distribuiÃÃo em classes de tamanho foi diferente entre as estaÃÃes de coleta, indicando influencia da densidade populacional. / The life history traits of an organism are the result of trade-offs between maintenance, growth and reproduction. This theory aims to explain the variations in the population aspects of a given species in function of the conditions and available resources in the environment, being the theoretical basis for studies dealing on the dependence of density. The density is a factor regulating the population dynamics since it promotes the competition for resources and, thus, it influences the attributes of life history. The present study aims to answer the following questions: does density influence size and sexual maturity in a population of the crab Goniopsis cruentata? Do the environmental conditions influence the biological aspects and increase the density effects on this species? Field work was conducted from January to November 2011, in the Municipalities of Aracati and Fortim (CearÃ, Brazil). The crabs were manually collected in two sampling stations, Alfredo and Caldeleiro, in an area of 400m for each station, during 40 minutes. The individuals collected were sexed and measured at the carapace width, gonopod length (males) and abdomen width (females). Ten individuals from each station were submitted to a histological procedure to determine the stage of gonad development. Density was calculated as the number of individuals per area (ind/mÂ). The individuals collected were distributed in size classes, by station and by sex. Morphological and physiological maturities were also calculated. Abiotic factors such as rainfall, pH and salinity of the soil were measured and correlated to the density of each station. The density of the Alfredo station was higher than the Caldeleiro station one, which may occur due to the greater availability of nutrients at this area, due to the lower pH than the Caldeleiro station. The rainfall was correlated to the density at Caldeleiro, due to the fact that this station presented a lower topography, suffering a greater influence of the level of the river. The salinity of the soil did not show differences between the stations. Males mean size did not differ between the stations, contrary to what occurred in females, with larger mean size at the highest density local. In both sexes, the larger maximum sizes were observed in the station with higher density, showing lower mortality between adults and, thus, allowing a delay in maturation at this local. The size class distribution did not differ between the stations, but presented a tendency to be bimodal at the station with higher density and unimodal at the station with lower density. This result may indicate the influence of the density in the distribution by size classes. The sexual maturity was anticipated in the lowest density local and delayed in the highest density local, as predicted by the life history theory. This pattern may be a result of higher mortality rates in juveniles at the highest density local and higher mortality rates between adults at the less dense area. The larger proportion of females observed at the highest density area may provide a spermatic limitation. Males, copulating with a higher number of females, do not have the capacity to produce spermatozoids to fertilize all of them. The results of the present study corroborate the predictions of the life history theory: (1) in populations with lower density, sexual maturity is anticipated and organisms attain smaller sizes, and in populations with higher density maturity is delayed and organisms attain larger sizes; (2) the distribution in size classes was different between the sampling areas, showing the influence of the population density.

Purpose: To assess the historical changes in the size and age of the US women’s Olympic gymnastics teams from 1956 to 2008. Methods: The official records from the US Olympic Committee and USA Gymnastics of Olympic team members were assessed at 2 levels: individual height, mass, age, and body-mass index (BMI) and the team performance scores and rankings. Fourteen Olympic teams with a total of 106 team members, including the alternates, were included. Trend analyses were conducted using linear and polynomial models. Results: Simple linear correlations indicated that since 1956, height, mass, age, BMI, and team Olympic rank have been declining. However, second-order polynomial curve fits indicated that in the last 4 Olympic Games the members of the US women’s gymnastics teams have been getting larger. Conclusion: Women Olympic gymnasts were getting smaller through approximately the 1980s and early 1990s. Since then the size of these gymnasts has increased. The minimum-age rule modifications may have played a role in athlete size changes along with a shift from the near dominance of the former communist Eastern Bloc.