jueves, enero 11, 2007

Bacterias gigantes?

El último número de la revista inglesa Nature publica un interesante artículo sobre una nueva interpretación de los microfósiles globulares de la Formación Doushantuo (China). Estos microfósiles de 600 millones de años fueron uno de los descubrimientos más importantes de la última década y se interpretaron como embriones animales teniendo en cuenta su tamaño y la división que presentan. En el nuevo trabajo de Jake Valey y colaboradores lo relacionan con bacterias sulfurosas gigantes.

Os adjuntamos el resumen: "The globular microfossils from the Neoproterozoic Doushantuo Formation in China are arguably one of the most significant fossil finds in the past decade. They were thought to be animal embryos, based on size and the presence of reductive cell division. If the attribution is correct, 600-million-year-old fossilized cells would provide an important window into early animal evolution. But they may not be embryos at all. The recent discovery of reductive cell division in a modern sulphur bacterium, and their direct association with phosphate minerals, find exact parallels in with the Doushantuo microfossils. Such an accumulation of animal embryos has always been seen as problematic, and no plausible phosphatization mechanism has been offered. The simplest explanation, therefore, is that these are the fossils of giant sulphur bacteria".
El texto completo se puede descargar en: http://www.nature.com/nature/journal/v445/n7124/edsumm/e070111-11.html
La referencia es: Evidence of giant sulphur bacteria in Neoproterozoic phosphorites. Jake V. Bailey, Samantha B. Joye, Karen M. Kalanetra, Beverly E. Flood and Frank A. Corsetti. doi:10.1038/nature05457

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