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Nephrotic Syndrome I : Introduction
Published on: June 19, 2025
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Origen gradual e independiente de las raíces entre las plantas terrestres
Alexander J Hetherington1, Liam Dolan2
1Department of Plant Sciences, University of Oxford, Oxford, UK.
Nature
|August 24, 2018
Resumen
Los descubrimientos fósiles revelan que las raíces de las plantas antiguas carecían de tapas protectoras, lo que sugiere que las raíces evolucionaron características complejas como las tapas gradualmente. Este hallazgo apoya las teorías de múltiples orígenes evolutivos de raíz en lugar de un solo evento.
Área de la Ciencia:
- La paleobotánica
- Biología evolutiva
- Anatomía de las plantas
Sus antecedentes:
- Las raíces son órganos vasculares vitales para el anclaje y la absorción de nutrientes / agua.
- El origen evolutivo de las tapas de raíz, una característica definidora de las raíces modernas, sigue sin estar claro debido a las limitaciones del registro fósil.
Objetivo del estudio:
- Investigar la evolución más temprana de los meristemas y las tapas de las raíces en las plantas vasculares.
- Para analizar la morfología de los órganos de enraizamiento en el antiguo licopsídeo Asteroxylon mackiei.
Principales métodos:
- Examen de hachas de enraizamiento fosilizadas del Rhynie chert de 407 millones de años de edad.
- Análisis microscópico de las estructuras del meristema en fósiles de Asteroxylon mackiei.
Principales resultados:
- Descubrimiento de los meristemas de raíz más antiguos conocidos en Asteroxylon mackiei, que datan de hace 407 millones de años.
- Estos meristemas antiguos carecían de tapas de raíz, presentando una epidermis continua en su lugar.
- Los órganos de enraizamiento de A. mackiei son únicos entre las plantas vasculares conocidas.
Conclusiones:
- La ausencia de tapas de raíz en las raíces licófitas tempranas apoya una evolución gradual de los rasgos de la raíz.
- Este hallazgo se alinea con la hipótesis de que las raíces evolucionaron varias veces de forma independiente (evolución convergente).
- El órgano de enraizamiento de transición de Asteroxylon mackiei proporciona información sobre el proceso de "ensamblaje" de las raíces durante la evolución de las plantas.
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