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FISH for Pre-implantation Genetic Diagnosis
Published on: February 23, 2011
Resolución de la radiación placentaria temprana de los mamíferos utilizando la filogenética bayesiana
W J Murphy1, E Eizirik, S J O'Brien
1Laboratory of Genomic Diversity, National Cancer Institute, Frederick, MD 21702, USA.
Science (New York, N.Y.)
|December 18, 2001
Resumen
La filogenia placentaria de los mamíferos revela a Afrotheria como el primer grupo divergente, originado hace unos 103 millones de años. Este hallazgo ayuda a comprender la historia biogeográfica temprana de los mamíferos placentarios.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- Filogenética molecular Filogenética molecular
- Paleontología de mamíferos Paleontología de mamíferos.
Sus antecedentes:
- La filogenia de los mamíferos placentarios se ha resuelto parcialmente en cuatro grupos principales.
- Las relaciones interordinales completas y la posición de la raíz siguen sin estar claras.
- Comprender la biogeografía placentaria temprana requiere resolver estas incertidumbres filogenéticas.
Objetivo del estudio:
- Para investigar la filogenia de los mamíferos placentarios utilizando datos moleculares.
- Establecer la jerarquía completa de las relaciones interordenarias.
- Para determinar la posición de la raíz y las implicaciones para la biogeografía temprana.
Principales métodos:
- Utilizó métodos bayesianos y filogenéticos de máxima probabilidad.
- Empleó un conjunto completo de datos moleculares de 16.4 kilobases.
- Analizó las relaciones interordenarias y los tiempos de divergencia.
Principales resultados:
- Se logró una resolución casi completa de las relaciones interordinales.
- Identificó la división basal entre Afrotheria y otros placentarios.
- Dató esta división basal hace aproximadamente 103 millones de años, potencialmente vinculada a la separación cretácea de América del Sur y África.
Conclusiones:
- La raíz de los mamíferos placentarios probablemente se encuentra en el hemisferio sur (Gondwana).
- La divergencia temprana de Afrotheria proporciona una visión crítica de la historia biogeográfica de los mamíferos.
- Este estudio refina nuestra comprensión de las relaciones evolutivas y la antigua distribución de los mamíferos placentarios.
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