Paleontology
Mostrando 25-33 de 33 artigos, teses e dissertações.
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25. Tempo and mode in the macroevolutionary reconstruction of Darwinism.
Among the several central meanings of Darwinism, his version of Lyellian uniformitarianism--the extrapolationist commitment to viewing causes of small-scale, observable change in modern populations as the complete source, by smooth extension through geological time, of all magnitudes and sequences in evolution--has most contributed to the causal hegemony of
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26. 150 years beyond Darwin's Origin of species: finding new approaches to reconstruct early animal phylogeny
The conference ‘Celebrating Darwin: From the Origin of Species to Deep Metazoan Phylogeny’ was held at the Humboldt University in Berlin, from 3 to 6 March 2009. Specialists from the fields of bioinformatics, molecular biology, developmental biology, comparative morphology and paleontology joined forces to present and discuss novel approaches in reconstr
The Royal Society.
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27. Immunological detection of hemoglobin in bones of ancient Roman times and of Iron and Eneolithic Ages.
Using an immunological method (immunoblot), we have established that hemoglobin (or hemoglobin fragments) can be quantitatively determined in old and ancient bones, some of them dating back 4500 years. It is shown that the total recovery decreases with time, but it is still effective in the older specimens. Thus, the immunological assay may prove useful to s
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28. Integrating the genotype and phenotype in hominid paleontology
Competing interpretations of human origins and evolution have recently proliferated despite the accelerated pace of fossil discovery. These controversies parallel those involving other vertebrate families and result from the difficulty of studying evolution among closely related species. Recent advances in developmental and quantitative genetics show that so
National Academy of Sciences.
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29. Opal phytoliths found on the teeth of the extinct ape Gigantopithecus blacki: implications for paleodietary studies.
Identification of opal phytoliths bonded to the enamel surface of the teeth of Gigantopithecus blacki indicates that this extinct ape had a varied diet of grasses and fruits. By using the scanning electron microscope at magnifications of 2000-6000x specific opal phytoliths were observed and photographed on the fossilized teeth of an extinct species. Since op
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30. A genetic record of population isolation in pocket gophers during Holocene climatic change
A long-standing question in Quaternary paleontology is whether climate-induced, population-level phenotypic change is a result of large-scale migration or evolution in isolation. To directly measure genetic variation through time, ancient DNA and morphologic variation was measured over 2,400 years in a Holocene sequence of pocket gophers (Thomomys talpoides)
The National Academy of Sciences.
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31. The Neandertal type site revisited: Interdisciplinary investigations of skeletal remains from the Neander Valley, Germany
The 1856 discovery of the Neandertal type specimen (Neandertal 1) in western Germany marked the beginning of human paleontology and initiated the longest-standing debate in the discipline: the role of Neandertals in human evolutionary history. We report excavations of cave sediments that were removed from the Feldhofer caves in 1856. These deposits have yiel
The National Academy of Sciences.
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32. Molecular paleontology of transposable elements in the Drosophila melanogaster genome
We report here a superfamily of “cut and paste” DNA transposons called Transib. These transposons populate the Drosophila melanogaster and Anopheles gambiae genomes, use a transposase that is not similar to any known proteins, and are characterized by 5-bp target site duplications. We found that the fly genome, which was thought to be colonized by t
National Academy of Sciences.
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33. Genome Dynamics and Evolution of the Mla (Powdery Mildew) Resistance Locus in BarleyW⃞
Genes that confer defense against pathogens often are clustered in the genome and evolve via diverse mechanisms. To evaluate the organization and content of a major defense gene complex in cereals, we determined the complete sequence of a 261-kb BAC contig from barley cv Morex that spans the Mla (powdery mildew) resistance locus. Among the 32 predicted genes
American Society of Plant Biologists.