Search results for " Darwin"

Termite Gut Symbiotic Archaezoa Are Becoming Living Metabolic Fossils

2003

ABSTRACT Over the course of several million years, the eukaryotic gut symbionts of lower termites have become adapted to a cellulolytic environment. Up to now it has been believed that they produce nutriments using their own cellulolytic enzymes for the benefit of their termite host. However, we have now isolated two endoglucanases with similar apparent molecular masses of approximately 36 kDa from the not yet culturable symbiotic Archaezoa living in the hindgut of the most primitive Australian termite, Mastotermes darwiniensis . The N-terminal sequences of these cellulases exhibited significant homology to cellulases of termite origin, which belong to glycosyl hydrolase family 9. The corre…

Keeping Track of Samples in Multidisciplinary Fieldwork

2021

We here present methods, tools and results for efficiently collecting metadata and tracking samples collected in the field. The samples and metadata were collected during scientific cruises conducted by amongst others marine biologists, oceanographers, geochemists and marine geologists in the Nansen Legacy project. It is here reported on the successful development and implementation of a system for labeling, tracking and openly publishing metadata from the cruises. The results and tools have been made openly available, as they are suitable for a range of situations, from the individual scientist working in the field to large research missions.

1809-2009, duecento anni di evoluzionismo

2010

Degradation of dimeric lignin model compounds by aerobic bacteria isolated from the hindgut of xylophagous termites.

1997

The capability of the intestinal flora from the gut of xylophagous termites of degrading lignin model compounds was investigated. Different dimeric lignin model compounds-degrading bacteria were obtained from the hindgut flora of Mastotermes darwiniensis FROGGATT, Reticulitermes santonensis FEYTAUD, Nasutitermes nigriceps HALDEMAN and Zootermopsis angusticollis HAGEN. In the presence of oxygen dimeric model compounds were degraded by all isolates. This indicates that the hindgut flora of termites is basically able to produce substrate for their host from aromatic extractives of wood.

La Educación Física Escolar en Tres Centros Educativos de Chile: una Caracterización de sus Prácticas Docentes

2016

Physical Education (PE) generally, and Chilean one, specifically, is in the middle of an identity crisis. There is a vision of the body as a production object. This vision has been generated in the light of social Darwinism, and at the same time there are other more conciliatory and global approaches. This investigation tries, with a holistic approach based on participating observation, to look into the practices carried out in relation to PE in schools in the Chilean context. The main conclusion from the analysis carried out is that in schools, PE is mainly focused on “doing” and on the production of results that can later on be assessed with objectivity. This means that schools are still …

Isolation of Desulfovibrio intestinalis sp. nov. from the hindgut' of the lower termite Mastotermes darwiniensis.

1999

A Gram-negative, anaerobic sulfate-reducing bacterium was isolated from hindgut contents of the lower termite Mastotermes darwiniensis Froggatt (strain KMS2). Strain KMS2 is motile by a single polar flagellum. The isolate possesses desulfoviridin and catalase activity. The G+C content of its DNA is in the range of 54.5-55.5 mol% (strain KMS2). It respires hydrogen and different low molecular weight organic compounds in the presence of sulfate, thiosulfate, and sulfite, and also oxygen. The isolated strain ferments pyruvate. Fastest growth with a doubling time of 12.5 h was obtained at 37°C and not at 28°C, the temperature at which the termites were grown. The isolate showed a 16S rDNA seque…

El darwinismo social y la filología decimonónica: rastreo de la ideología a través de la prensa histórica

2021

espanolEn este trabajo, se persigue demostrar que el pensamiento darwiniano estaba enraizado en concepciones supremacistas y que este pensamiento no solo marco la biologia decimononica, sino tambien el resto de disciplinas sociales y humanas al convertirse la biologia como maximo exponente de lo que se entendia como ciencia. No solo se tomaron como premisas los presupuestos metodologicos de la biologia, sino tambien su concepcion supremacista. Y la filologia no fue una excepcion. A traves del rastreo en la prensa historica decimononica, queremos demostrar que estas ideas calaron en la sociedad, pero tambien en el pensamiento filologico hispanico del siglo XIX. La reconstruccion de la preten…

Positivism on the move: translators and publishers in Mexico and Argentina (1850-1950)

2013

La historiografía sobre el tema ha mostrado que la introducción de la filosofía de Auguste Comte en Latinoamérica dio lugar a un positivismo profundamente heterogéneo. Su combinación con los escritos de Herbert Spencer, Charles Darwin y John Stuart Mill, la circulación de impresos, tanto en lengua original como en traducción, y el desarrollo de un mercado editorial internacional a fines del siglo XIX son algunos de los factores que contribuyen a explicar dicha heterogeneidad. El presente trabajo estudia la circulación de las ideas positivistas en Argentina y en México desde la perspectiva de los editores y traductores activos entre 1850 y 1950, un periodo clave para la organización política…

Hybridization as Speciation? The Viewpoint of Greek Folk Biology (and Aristotle) on the Mutation of Species

2008

Modern evolutionary biologists, as for example Michael Arnold, attest that hybridizations could have a strong creative force in organismal evolution. Such an idea was considered as blasphemous by 19th century critics on evolutionism, and did not entirely convince Charles Darwin himself, but it would not have surprised the ancient Greeks and Romans, who knew that inter-specific couplings gave birth to new species. These new species, however, were considered as products of a process of "adulteration" or "involution", rather than "evolution".

‘Happy amicable co-operation’: mutual aid, anarchism and the image of the bee in the work of Louisa Sarah Bevington

2017

AbstractThe poet and political activist Louisa Sarah Bevington has been largely ignored in accounts of late Victorian literary and cultural history, even though her work presents a singular nexus of scientific, socio-cultural and poetical perspectives. This essay will show how Bevington juxtaposes Social Darwinist interpretations of the theory of evolution, which foreground the idea of human life as a struggle for existence, with the anarcho-communist view proposed by Peter Kropotkin, which foregrounds the human capacity for sympathy and mutual aid as the driving forces in social development. After situating Kropotkin’s ideas within the larger context of anarchist and evolutionist thinking,…