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Las firmas elementales de los dientes de Australopithecus africanus revelan estrés dietético estacional
Renaud Joannes-Boyau1, Justin W Adams2,3, Christine Austin4
1Geoarchaeology and Archaeometry Research Group, Southern Cross GeoScience, Southern Cross University, Lismore, New South Wales, Australia. renaud.joannes-boyau@scu.edu.au.
Nature
|July 17, 2019
Resumen
Los bebés de Australopithecus africanus dependían de la leche materna durante su primer año. El análisis de oligoelementos de sus dientes revela la disponibilidad fluctuante de alimentos y adaptaciones fisiológicas al estrés dietético en los primeros homínidos.
Área de la Ciencia:
- Paleoantropología
- Paleoecología
- Geoquímica
Sus antecedentes:
- La reconstrucción de las dietas de homínidos extintos es un desafío, especialmente para Australopithecus africanus con su morfología variable.
- La comprensión de las respuestas dietéticas a la escasez de alimentos estacionales y los comportamientos de lactancia en homínidos extintos es limitada.
- Los análisis previos de oligoelementos se centraron en el Homo sapiens, el Homo neanderthalensis y los simios vivos.
Objetivo del estudio:
- Para investigar el comportamiento dietético y las adaptaciones ecológicas de Australopithecus africanus.
- Reconstruir los patrones de lactancia y la disponibilidad de alimentos experimentados por los bebés de A. africanus.
- Evaluar el impacto de la fluctuación de los recursos en la supervivencia de A. africanus.
Principales métodos:
- Análisis geoquímico de alta resolución de elementos traza de dos dientes de A. africanus de Sterkfontein Miembro 4 hace 2,6-2,1 millones de años.
- Análisis de las señales elementales para determinar la duración de la lactancia y los patrones dietéticos.
- Pruebas isotópicas para inferir el alcance geográfico y la disponibilidad de recursos.
Principales resultados:
- Las señales elementales indican un consumo prolongado de leche materna durante el primer año de la infancia de A. africanus.
- Los patrones elementales cíclicos sugieren una disponibilidad irregular de alimentos y estrés dietético estacional.
- La acumulación de litio en los dientes corrobora los fluctuantes recursos y las adaptaciones fisiológicas.
Conclusiones:
- Los bebés de A. africanus tenían comportamientos específicos de lactancia y experimentaron una escasez significativa de alimentos estacionales.
- La especie exhibió adaptaciones fisiológicas a condiciones ambientales inestables.
- El estrés dietético en A. africanus puede haber contribuido a su extinción poco después de este período.
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