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Metric versus non-metric skeletal traits : which is the more reliable indicator of genetic distance?Powell, J. E. January 1989 (has links)
No description available.
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Análise comparativa dos padrões de covariação genética e fenotípica no crânio e mandíbula de Calomys expulsus (Rodentia: Muroidea) / Comparative analysis of phenotypic and genetic covariances in the skull and mandible of the vesper mouse Calomys expulsus (Rodentia: Muroidea)Garcia, Guilherme Rodrigues Gomes 27 April 2011 (has links)
Os padrões de covariância genética entre caracteres, expressos pela matriz de covariância aditiva G, desempenham um papel importante na evolução de morfologias complexas, visto que esta matriz influencia a direção e magnitude da resposta à seleção em uma população. Assumindo-se a estabilidade da matriz G ao longo do tempo, pode-se testar explicitamente hipóteses acerca da influência de processos evolutivos sobre a diversificação. Espera-se que esta matriz influencie os padrões expressos por sua equivalente fenotípica P, devido a contingências funcionais e ontogenéticas na relação entre genótipo e fenótipo, que levam à estruturação de modularidade nesta relação, de modo a otimizar a evolvabilidade. No presente trabalho, investiguei a estrutura da covariância genética no crânio e mandíbula de uma população do roedor sigmodontíneo Calomys expulsus, com o objetivo de estimar a similaridade entre covariâncias fenotípicas e genéticas; também avaliei a influência de padrões de modularidade sobre ambos os níveis de organização da variação morfológica. As matrizes P e G que obtive para o crânio e para a mandíbula se mostraram bastante similares no que diz respeito à sua estrutura de covariação e se relacionam parcialmente às hipótese de modularidade estabelecidas. Os resultados que obtive aqui são bastante similares àqueles obtidos para os mamíferos como um todo, portanto suportando a hipótese de estabilidade no padrão de covariâncias genéticas e fenotípicas na evolução do grupo. / Patterns of genetic covariance between characters (represented by the additive covariance matrix G) play an important role in the evolution of morphological complexes, since they influence the direction and norm of the response to selection in a population. Therefore, the assumption that G-matrices are stable through evolutionary timescales allows evolutionary biologists to infer the influence of evolutionary processes that operate over biological diversification. These matrices are also expected to influence the patterns expressed in their phenotypic counterparts (P-matrix), because of the imposition of multiple developmental and functional contingencies over the genotype/phenotype map, that leads to its modular organization in order to increase evolvability. Here, I have investigated patterns of genetic covariance structure in the skull and mandible of a population of the vesper mouse Calomys expulsus in order to estimate the level of similarity between additive and phenotypic covariances; I have also evaluated the influence of expected patterns of modularity over both levels of morphological variation. For either skull and mandible, I have obtained P- and G-matrices that are strongly similar in their structure; these matrices also support the modularity hypotheses for developmental and functional constrains, akin to the overall results obtained for mammals, thus supporting the hypothesis of stability in genetic and phenotypic covariance structure in mammalian evolution.
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Part I¡GCharacterization of humoral immune responses of mice infected with Angiostrongylus cantonensis Part II¡GAnalysis on the cranial morphology of mice infected with Angiostrongylus cantonensisYang, Zhi-Ya 10 September 2002 (has links)
Abstract -1
The immune response occurred in the mice infected with
Angiostrongylus cantonensis was mainly humoral immune
response. This study was designed to compare the systemic and
localized humoral immune responses occurred after primary and
secondary infections in C57BL/6J mice. Eight weeks after the
primary infection with 20 third-stage larvae, each mouse received a
second inoculation of the same dosage. Specific serum IgM, IgG
and IgE were found in the second week after primary infection.
However, the titers of IgG1 and IgG2b increased at the fourth week
after primary infection. Antibodies of these mentioned increased
continuously as the progress of infection. On the other hand, the
IgM and IgG1 titers increased in brain tissue infusion since the forth
week after primary infection, while the titer of IgG start to elevate at
the sixth week. Nevertheless, the increase of IgG2B was only
noticed at the sixth week and no significant change was observed
for IgG2a and IgE. After the secondary infection, serum IgM titers
increased while the titer of IgG1 in the brain tissue infusion
decreased. Results of Western blot showed that IgG1and IgE in the
brain tissue infusion lost the ability to recognize a 42 kDa molecule
of the somatic and excreting-secreting antigens of fifth-stage
larvae. These variations could be used in the diagnosis of the early
stage of mice that re-infected with Angiostrongylus cantonensis. Abstract -2
The radiographic lateral views of the skulls of the mice infected
with Angiostrongylus cantonensis were taken. Thus, the
parietofrontal index ( PI ) was obtained by measuring and
calculating the distances among specific positions on their skulls.
Compared with the controls, a significant elevation over the top of
the crania of the cases was observed sixty days post-infection. In
addition, the phenomenon emerged apparently during the second
to the fourth week post-infection. These findings are able to be
applied as the external diagnostic references for the infection
course of mice infected with Angiostrongylus cantonensis.
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Análise comparativa dos padrões de covariação genética e fenotípica no crânio e mandíbula de Calomys expulsus (Rodentia: Muroidea) / Comparative analysis of phenotypic and genetic covariances in the skull and mandible of the vesper mouse Calomys expulsus (Rodentia: Muroidea)Guilherme Rodrigues Gomes Garcia 27 April 2011 (has links)
Os padrões de covariância genética entre caracteres, expressos pela matriz de covariância aditiva G, desempenham um papel importante na evolução de morfologias complexas, visto que esta matriz influencia a direção e magnitude da resposta à seleção em uma população. Assumindo-se a estabilidade da matriz G ao longo do tempo, pode-se testar explicitamente hipóteses acerca da influência de processos evolutivos sobre a diversificação. Espera-se que esta matriz influencie os padrões expressos por sua equivalente fenotípica P, devido a contingências funcionais e ontogenéticas na relação entre genótipo e fenótipo, que levam à estruturação de modularidade nesta relação, de modo a otimizar a evolvabilidade. No presente trabalho, investiguei a estrutura da covariância genética no crânio e mandíbula de uma população do roedor sigmodontíneo Calomys expulsus, com o objetivo de estimar a similaridade entre covariâncias fenotípicas e genéticas; também avaliei a influência de padrões de modularidade sobre ambos os níveis de organização da variação morfológica. As matrizes P e G que obtive para o crânio e para a mandíbula se mostraram bastante similares no que diz respeito à sua estrutura de covariação e se relacionam parcialmente às hipótese de modularidade estabelecidas. Os resultados que obtive aqui são bastante similares àqueles obtidos para os mamíferos como um todo, portanto suportando a hipótese de estabilidade no padrão de covariâncias genéticas e fenotípicas na evolução do grupo. / Patterns of genetic covariance between characters (represented by the additive covariance matrix G) play an important role in the evolution of morphological complexes, since they influence the direction and norm of the response to selection in a population. Therefore, the assumption that G-matrices are stable through evolutionary timescales allows evolutionary biologists to infer the influence of evolutionary processes that operate over biological diversification. These matrices are also expected to influence the patterns expressed in their phenotypic counterparts (P-matrix), because of the imposition of multiple developmental and functional contingencies over the genotype/phenotype map, that leads to its modular organization in order to increase evolvability. Here, I have investigated patterns of genetic covariance structure in the skull and mandible of a population of the vesper mouse Calomys expulsus in order to estimate the level of similarity between additive and phenotypic covariances; I have also evaluated the influence of expected patterns of modularity over both levels of morphological variation. For either skull and mandible, I have obtained P- and G-matrices that are strongly similar in their structure; these matrices also support the modularity hypotheses for developmental and functional constrains, akin to the overall results obtained for mammals, thus supporting the hypothesis of stability in genetic and phenotypic covariance structure in mammalian evolution.
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Genomic and Climatic Effects on Human Crania from South America: A Comparative Microevolutionary ApproachHerrera, Brianne 04 September 2019 (has links)
No description available.
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Impacts of Habitat Fragmentation on the Cranial Morphology of a Threatened Desert Fish (Cyprinodon Pecosensis)Gilbert, Michael Chaise 01 July 2016 (has links)
Drastic alterations to the North American Southwest’s hydrology have highly influenced resident fish communities. In New Mexico and Texas, the Pecos River has been severely altered as a result of water manipulation, isolating backwaters and various habitats that were once connected to the main river. Cyprinodon pecosensis (Pecos pupfish) has been highly impacted due to the effects of anthropogenic water manipulation, as well as species introductions. Cyprinodon pecosensis populations have become isolated and scattered, residing in sinkholes, remnant lakes, and static backwaters, thus creating numerous micropopulations. The purpose of this study was to assess the morphological variation in cranial features that occur in response to varied habitats, especially in terms of environmental factors and species co-occurrence. Landmark-based geometric morphometrics was used to assess shape variation across the aforementioned micropopulations comprising four general habitat types and 27 different localities, each with varied community structure and salinity. Results from this study suggest that head and mandible morphology vary temporally, with year to year variation, as well as among different localities. The head morphology of C. pecosensis was most heavily influenced by habitat type and localities within habitat types, but was largely canalized with the exception of localities classified as deep sinkholes. Year to year variation and localities among habitat types were the most influential factors associated with mandible morphology, but there was strong overlap among the convex hulls that defined regions of morphospace for habitat types. As C. pecosensis is a threatened species, this research has important implications for future conservation and management. Additionally, these results could further aid in the understanding of preserving species in fragmented landscapes.
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Descrição de Novos Materiais Referentes à Tapejaridae (pterosauria, Pterodactyloidea) da Formação Romualdo (Bacia do Araripe, Ceará, Brasil)Aires, Alex Sandro Schiller January 2013 (has links)
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Previous issue date: 2013 / O clado Pterosauria é constituído por répteis alados que viveram durante a Era
Mesozóica (entre 215 a 65 milhões de anos antes do presente) e habitaram diversas regiões do
planeta. Pertencente a este clado, o g rupo Tapejaridae é caracterizado principalmente pela
peculiar morfologia rostral e por não possuir dentes. O estudo filogenético de tapejarídeos do
nordeste do Brasil é baseado na sua maioria em elementos do crânio, devido à escassez de esqueletos
pós-cranianos. Este estudo descreve morfologicamente e classifica, através de análise filogenética,
um novo espécime atribuído à Tapejaridae, proveniente da Formação Romualdo (Grupo
Santana, Bacia do Araripe, CE). O material compreende dez vértebras articuladas (as três
últimas cervicais e também as sete primeiras dorsais que se fusionam, formando o notário), o
escapulocoracóide direito, a escápula e o coracóide esquerdos, um fragmento de esterno, o
úmero direito parcialmente preservado, um fragmento da 4a falange do dígito alar, a porção
distal do femur direito e a porção proximal da tíbia/fíbula . Foram geradas três árvores na
análise filogenética, sendo que em duas delas AMNH 22567 foi posicionado dentro de
Thalassodrominae . Contudo, na outra árvore o espécime se pocisionou como Tapejaridae basal.
Mesmo assim, sua assignação como Thalassodrominae se justifica pela presença de três foramens
posicionados dorsal e lateralmente ao canal neural nas vértebras cervicais; presença de notário e
presença de um forâmen pneumático ventral na porção proximal do úmero. Estes materiais são os
mais completos elementos pós-cranianos deste grupo de pterossauros descritos até o
momento. Com relação à paleobiogeografia, Tapejaridae aparenta ter surgido no oeste da
Eurásia durante o Neojurássico, migrando para sudoeste e dando origem as formas
eocretácicas da Bacia do Araripe. / Pterosauria is a clade composed of flying reptiles that lived during the Mesozoic Era
(215 to 65 million of years before present) and inhabited various regions of the world. Within
this large clade, Tapejaridae is mainly characterized by peculiar rostral morphology and
absence of tooths. The phylogenetical studies of the tapejarids from northeastern Brazil are
mainly based on cranial elements, due to shortage of postcranial skeletons. This study
described and classified through a phylogenetical analysis, a new specimen ascribed to
Tapejaridae from Romualdo Formation (Araripe Basin, CE), housed at the American Museum
of Natural History (under the acronym AMNH 22567) and comments on the
paleobiogeography of this group. The material comprises ten articulated vertebrae (three
cervicals and seven subsequent dorsals fusioned, ones forming the notarium), a right
scapulocoracoid, a left scapula and a left coracoid, a partial sternum, a right humerus, a
fragment of 4th phalanx of the alar digit, a distal fragment of right femur and a fragment of
the proximal portion of the right tibia/fibula. The phylogenetical analysis generated three
different topologies, two of them placing AMNH 22567 within Thalassodrominae (subclade
of Tapejaridae). In the other one, the specimen was placed in a basal position within
Tapejaridae. Nonetheless, the presence of three foramina lateral and dorsal to the neural canal
of the cervical vertebrae, the presence of a notarium and presence of a pneumatic foramen on
the ventral side of the proximal portion of the humerus allow its assignation as a
Thalassodrominae indet. The specimen comprises the more complete postcranial material for
this subfamily described so far. Regarding the paleobiogeography of Tapejaridae, it appears to
originated in western Eurásia during the Neojurassic and later migrated to southwest and
irradiated to new Eocretacic forms in Araripe Basin.
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Craniometric Ancestry Proportions among Groups Considered Hispanic: Genetic Biological Variation, Sex-Biased Asymmetry, and Forensic ApplicationsTise, Meredith L. 01 May 2014 (has links)
Today, groups considered Hispanic in the United States consist of populations whose complex genetic structures reflect intermixed diverse groups of people who came in contact during Spanish colonization in Latin America. After coming in contact and wiping out most of the Native Americans who occupied North and Latin America, the Spanish also introduced West African individuals for labor to begin developing crops to be shipped back to Europe, resulting in the Trans-Atlantic African slave trade. These migration events and differential gene flow among males and females that occurred throughout Latin America have led to populations that have been genetically transformed from what they were prior to Spanish arrival (Madrigal, 2006).
Genetic research commonly refers to individuals considered Hispanic as "tri-hybrids" of Native American, European, and African ancestry (Bertoni et al., 2003; Gonz[aacute]lez-Andrade et al., 2007). This research focuses on populations from present-day Mexico, Puerto Rico, and Cuba, all of whom experienced various population histories as these three ancestral groups came in contact. Published genetic research demonstrates that individuals from Mexico tend to have the highest mean proportion of Native American ancestry, while Puerto Rican individuals have the highest mean proportion of European ancestry, and Cuban individuals have the highest mean proportion of African ancestry (Bonilla et al., 2005; Lisker et al., 1990; Mendizabal et al., 2008; Tang et al., 2007; Via et al., 2011). The present research utilizes craniometric data from these three groups to determine whether the cranial morphology reflects similar population relationships and mean ancestry proportions as found in genetic research through Mahalanobis distance (D2), canonical discriminant function, and normal mixture cluster analyses. Sex-biased ancestry asymmetry was also tested by separating each group by sex and running the same analyses.
The results show that all three groups considered Hispanic (Mexico, Puerto Rico, and Cuba) are significantly different from each other; however, when proxy ancestral groups are included (Guatemalan Mayan, Indigenous Caribbean, Spanish, and West African), the Mexican and Guatemalan Mayan samples are the most similar, followed by the Mexican and Indigenous Caribbean samples and the Puerto Rican and Cuban samples. The results of the normal mixture analyses indicate that Mexico has the highest mean ancestry proportion of Native American (Guatemalan Mayan) (72.9%), while the Puerto Rican and Cuban samples both have a higher mean European ancestry proportion, with 81.34% and 73.6% respectively. While the Cuban sample is not reflective of the genetic research in regards to ancestry proportion results, with the highest proportion of African ancestry over European and Native American ancestry, it does have the highest proportion of African ancestry among the three groups (18.4%). When separated by sex, the results indicate that the Mexican and Puerto Rican samples may show some evidence in sex-biased ancestry proportions, with the male individuals having a larger proportion of European ancestry and the female individuals having a larger proportion of Native American or African ancestry. Cuba, on the other hand, does not follow this trend and instead displays a higher proportion of European ancestry in females and a higher proportion of Native American and African ancestry in the males.
Techniques in the field of forensic anthropology in the United States are constantly being reanalyzed and restructured based on the changing demographics of the population, especially with the arrival of individuals from Latin America (Ennis et al., 2011). Recent samples of American Black and White individuals were included in the Mahalanobis distance (D2) and canonical discriminant function analyses in place of the ancestral proxy groups to determine the craniometric relationship of the groups within the United States. The results show that the Mexico and Guatemala samples are the most similar (D2=2.624), followed by the Cuba and American Black samples (D2=3.296) and the Puerto Rico and American White samples (D2=4.317), which each cluster together in pairs. These results reflect the population histories that took place during colonialism, with the largest amount of slave trade occurring in Cuba over the other two countries. From an applied perspective, clarification is needed in the biological definition of Hispanic and the degree of heterogeneity in each social group, as well as the relationship among groups, in order to accurately develop techniques in forensic anthropology for human identification.
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Cranial Morphology and Systematics of Late Pliocene <em>Alligator</em> from Florida, with Notes on <em>Alligator</em> Evolution and Distribution.Stout, Jeremy Brett 19 December 2009 (has links) (PDF)
Alligator mississippiensis is only distantly related to the other extant alligator (A. sinensis), with much closer relatives known from the geologic past of North America. While A. mississippiensis is well known from the early Pleistocene and later, no Alligator was known from the middle and late Pliocene until the discovery of Haile 7C and 7G late Pliocene (~2 Ma) sites from Florida. These specimens were analyzed using a diagnostic character matrix along with systematic analyses of the results. This research upholds A. mefferdi as a valid taxon, and the utility of the species in fossil identification is further established. The Haile material cannot be placed within either of the aforementioned taxa, and a new species description is planned in a later publication. Furthermore, the systematic analysis used in this research suggests that the line leading to A. sinensis diverged before the earliest known Alligator. An Eocene dispersal of the genus into Asia is plausible.
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Descrição de novos materiais referentes à tapejaridae (pterosauria, pterodactyloidea) da formação romualdo (bacia do Araripe, Ceará, Brasil) / Description of new materials related to the tapejaridae (pterosauria, pterodactyloidea) of the romualdo formation (Araripe basin, Ceará, Brazil)Aires, Alex Sandro Schiller 19 February 2013 (has links)
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Previous issue date: 2013-02-19 / O clado Pterosauria é constituído por répteis alados que viveram durante a Era Mesozóica (entre 215 a 65 milhões de anos antes do presente) e habitaram diversas regiões do planeta. Pertencente a este clado, o grupo Tapejaridae é caracterizado principalmente pela peculiar morfologia rostral e por não possuir dentes. O estudo filogenético de tapejarídeos do nordeste do Brasil é baseado na sua maioria em elementos do crânio, devido à escassez de esqueletos pós-cranianos. Este estudo descreve morfologicamente e classifica, através de análise filogenética, um novo espécime atribuído à Tapejaridae, proveniente da Formação Romualdo (Grupo Santana, Bacia do Araripe, CE). O material compreende dez vértebras articuladas (as três últimas cervicais e também as sete primeiras dorsais que se fusionam, formando o notário), o escapulocoracóide direito, a escápula e o coracóide esquerdos, um fragmento de esterno, o úmero direito parcialmente preservado, um fragmento da 4ª falange do dígito alar, a porção distal do femur direito e a porção proximal da tíbia/fíbula. Foram geradas três árvores na análise filogenética, sendo que em duas delas AMNH 22567 foi posicionado dentro de Thalassodrominae. Contudo, na outra árvore o espécime se pocisionou como Tapejaridae basal. Mesmo assim, sua assignação como Thalassodrominae se justifica pela presença de três foramens posicionados dorsal e lateralmente ao canal neural nas vértebras cervicais; presença de notário e presença de um forâmen pneumático ventral na porção proximal do úmero. Estes materiais são os mais completos elementos pós-cranianos deste grupo de pterossauros descritos até o momento. Com relação à paleobiogeografia, Tapejaridae aparenta ter surgido no oeste da Eurásia durante o Neojurássico, migrando para sudoeste e dando origem as formas eocretácicas da Bacia do Araripe. / O clado Pterosauria é constituído por répteis alados que viveram durante a Era Mesozóica (entre 215 a 65 milhões de anos antes do presente) e habitaram diversas regiões do planeta. Pertencente a este clado, o grupo Tapejaridae é caracterizado principalmente pela peculiar morfologia rostral e por não possuir dentes. O estudo filogenético de tapejarídeos do nordeste do Brasil é baseado na sua maioria em elementos do crânio, devido à escassez de esqueletos pós-cranianos. Este estudo descreve morfologicamente e classifica, através de análise filogenética, um novo espécime atribuído à Tapejaridae, proveniente da Formação Romualdo (Grupo Santana, Bacia do Araripe, CE). O material compreende dez vértebras articuladas (as três últimas cervicais e também as sete primeiras dorsais que se fusionam, formando o notário), o escapulocoracóide direito, a escápula e o coracóide esquerdos, um fragmento de esterno, o úmero direito parcialmente preservado, um fragmento da 4ª falange do dígito alar, a porção distal do femur direito e a porção proximal da tíbia/fíbula. Foram geradas três árvores na análise filogenética, sendo que em duas delas AMNH 22567 foi posicionado dentro de Thalassodrominae. Contudo, na outra árvore o espécime se pocisionou como Tapejaridae basal. Mesmo assim, sua assignação como Thalassodrominae se justifica pela presença de três foramens posicionados dorsal e lateralmente ao canal neural nas vértebras cervicais; presença de notário e presença de um forâmen pneumático ventral na porção proximal do úmero. Estes materiais são os mais completos elementos pós-cranianos deste grupo de pterossauros descritos até o momento. Com relação à paleobiogeografia, Tapejaridae aparenta ter surgido no oeste da Eurásia durante o Neojurássico, migrando para sudoeste e dando origem as formas eocretácicas da Bacia do Araripe.
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