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Datando el cráneo de Broken Hill, Zambia, y su posición en la evolución humana
Rainer Grün1,2, Alistair Pike3, Frank McDermott4
1Australian Research Centre for Human Evolution, Griffith University, Nathan, Queensland, Australia. Rainer.Grun@griffith.edu.au.
Nature
|April 17, 2020
Resumen
El cráneo de Broken Hill, que una vez se pensó que tenía 500,000 años, ahora está fechado a 299,000 años. Este hallazgo revela múltiples linajes de homínidos que coexistieron en el Pleistoceno Medio de África, impactando nuestra comprensión de la evolución humana.
Área de la Ciencia:
- Paleoantropología
- Estudios de la evolución humana
- Paleontología africana
Sus antecedentes:
- El cráneo de Broken Hill (Kabwe), un espécimen homínido fósil clave, fue recuperado en Zambia en 1921.
- Anteriormente clasificado como Homo rhodesiensis o Homo heidelbergensis, su edad y ubicación evolutiva eran inciertas debido a su recuperación no sistemática y la falta de una datación precisa.
Objetivo del estudio:
- Para fechar con precisión el cráneo de Broken Hill usando el análisis directo.
- Para reevaluar el contexto evolutivo de las poblaciones de homínidos en el Pleistoceno Medio de África.
Principales métodos:
- El análisis directo del cráneo de Broken Hill.
- Las técnicas de datación radiométrica para establecer una estimación precisa de la edad.
Principales resultados:
- Una estimación revisada de edad para el cráneo de Broken Hill de 299 ± 25 mil años (media ± 2σ).
- Esta edad indica la presencia de múltiples linajes de homínidos, incluidos Homo sapiens, Homo heidelbergensis / Homo rhodesiensis y Homo naledi, que coexistieron en África durante el Pleistoceno Medio posterior.
Conclusiones:
- La datación desafía las suposiciones anteriores sobre un solo linaje ancestral para el Homo sapiens en África.
- Sugiere una imagen más compleja de la diversidad de homínidos en el Pleistoceno Medio de África, comparable a Eurasia.
- Plantea preguntas sobre el papel ancestral directo de Homo heidelbergensis / Homo rhodesiensis en la evolución del Homo sapiens.
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