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La inclinación reproductiva y la selección en la ornamentación femenina en especies sociales
Dustin R Rubenstein1, Irby J Lovette
1Columbia University, Department of Ecology, Evolution and Environmental Biology, 10th Floor Schermerhorn Extension, 1200 Amsterdam Avenue, New York, New York 10027, USA. dr2497@columbia.edu
Nature
|December 17, 2009
Resumen
La selección sexual generalmente favorece los rasgos masculinos elaborados. Sin embargo, en las aves que se reproducen cooperativamente, la intensa competencia femenina reduce el dimorfismo sexual, lo que lleva a hembras más ornamentadas y presiones evolutivas alteradas.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- Ecología del comportamiento Ecología del comportamiento.
- Ornitología Ornitología.
Sus antecedentes:
- La teoría clásica de la selección sexual postula que los machos desarrollan rasgos elaborados debido a un mayor potencial reproductivo y una menor inversión parental.
- Esto a menudo conduce al dimorfismo sexual sesgado masculino en los personajes sexuales secundarios.
Objetivo del estudio:
- Investigar cómo la reproducción cooperativa influye en el dimorfismo sexual en los rasgos relacionados con la competencia intrasexual.
- Para probar si el dimorfismo sexual reducido es evidente en especies que se reproducen cooperativamente debido a intensidades de selección comparables en ambos sexos.
Principales métodos:
- Examinó el dimorfismo sexual en el plumaje y el tamaño del cuerpo en estorninos africanos (Sturnidae) socialmente diversos.
- Niveles de dimorfismo comparados entre especies de reproducción cooperativa y no cooperativa.
Principales resultados:
- Dimorfismo sexual reducido demostrado en el plumaje y el tamaño del cuerpo en especies de estorninos de reproducción cooperativa.
- Se encontró una mayor selección en las hembras para los rasgos que mejoran el acceso a los recursos y el estatus social en estas especies.
Conclusiones:
- La reproducción cooperativa puede igualar o incluso revertir las presiones típicas de selección sexual, lo que lleva a una mayor ornamentación femenina.
- La intensa competencia hembra-hembra en los criadores cooperativos impulsa la evolución de los rasgos femeninos, lo que afecta el dimorfismo sexual.
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