916 resultados para traditional film history
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Background The infraorder Anomura has long captivated the attention of evolutionary biologists due to its impressive morphological diversity and ecological adaptations. To date, 2500 extant species have been described but phylogenetic relationships at high taxonomic levels remain unresolved. Here, we reconstruct the evolutionary history—phylogeny, divergence times, character evolution and diversification—of this speciose clade. For this purpose, we sequenced two mitochondrial (16S and 12S) and three nuclear (H3, 18S and 28S) markers for 19 of the 20 extant families, using traditional Sanger and next-generation 454 sequencing methods. Molecular data were combined with 156 morphological characters in order to estimate the largest anomuran phylogeny to date. The anomuran fossil record allowed us to incorporate 31 fossils for divergence time analyses. Results Our best phylogenetic hypothesis (morphological + molecular data) supports most anomuran superfamilies and families as monophyletic. However, three families and eleven genera are recovered as para- and polyphyletic. Divergence time analysis dates the origin of Anomura to the Late Permian ~259 (224–296) MYA with many of the present day families radiating during the Jurassic and Early Cretaceous. Ancestral state reconstruction suggests that carcinization occurred independently 3 times within the group. The invasion of freshwater and terrestrial environments both occurred between the Late Cretaceous and Tertiary. Diversification analyses found the speciation rate to be low across Anomura, and we identify 2 major changes in the tempo of diversification; the most significant at the base of a clade that includes the squat-lobster family Chirostylidae. Conclusions Our findings are compared against current classifications and previous hypotheses of anomuran relationships. Many families and genera appear to be poly- or paraphyletic suggesting a need for further taxonomic revisions at these levels. A divergence time analysis provides key insights into the origins of major lineages and events and the timing of morphological (body form) and ecological (habitat) transitions. Living anomuran biodiversity is the product of 2 major changes in the tempo of diversification; our initial insights suggest that the acquisition of a crab-like form did not act as a key innovation.
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The Maya of the Yucatan region have a long history of keeping the native stingless bees (subfamily Meliponinae). However, market forces in the last few decades have driven the Maya to favor the use of invasive Africanized honey bees (Apis mellifera scutellata) for producing large quantities of high quality honey that has an international market. Furthermore, the native bees traditionally used by the Maya are now disappearing, along with the practice of keeping them. ^ An interdisciplinary approach was taken in order to determine the social factors behind the decrease in stingless beekeeping and the ecological driving forces behind their disappearance from the wild. Social research methods included participant observation with stingless beekeepers, Apis beekeepers, and marketing intermediaries. Ecological research methods included point observations of commonly known melliferous and polliniferous plants along transects in three communities with different degrees of human induced ecosystem disturbance. ^ The stingless bee species most important to the Maya, Melipona beecheii, has become extremely rare, and this has caused a breakdown of stingless beekeeping tradition, compounded with the pressure of the market economy, which fuels Apis beekeeping and has lessened the influence of traditional practices. The community with the heaviest amount of human induced ecosystem disturbance also had the highest degree of dominance of Apis mellifera, while the area with the most intact ecosystem had the highest diversity of stingless bees, though Apis mellifera was still the dominant species. Aggressive competitive behavior involving physical attacks by Apis mellifera against stingless bees was observed on several occasions, and this is a new observation previously unreported by science. ^
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The purpose of this thesis is to explore deprivation experienced by the nineteenth century Sioux who suffered the loss of traditional lands, economic independence, buffalo, tribal customs, and religion. After years of reservation life, starvation, and deprivation at the hands of the U.S. government, white settlers, and reservation agents, the Sioux anxiously sought out a Paiute Indian Messiah named Wovoka whose message of a new Indian world spread rapidly throughout the Dakotas. The use of extensive historical and religious documents, as well as primary sources, will argue that the extent of desperation experienced by the Sioux drove them to accept the Ghost Dance as a substitute for the Sun Dance, the center of their traditional religious complex. With its hope of the resurrection of dead Indians, return of the buffalo, and renewal of the earth, it was immediately adopted leading ultimately to the massacre at Wounded Knee in 1890 and the passing of Wovoka's religion into history.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.