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Conservadurismo de nichos ecológicos en el tiempo evolutivo
Peterson1, Sober n J, Sanchez-Cordero
1Natural History Museum, The University of Kansas, Lawrence, KS 66045, USA. Instituto de Ecologia, Universidad Nacional Autonoma de Mexico, Mexico, D.F. 04510, Mexico. Departamento de Zoologia, Instituto de Biologia, Universidad Nacional A.
Science (New York, N.Y.)
|August 24, 1999
Resumen
Los nichos ecológicos de las especies muestran una estabilidad sorprendente durante millones de años, lo que sugiere que el aislamiento geográfico impulsa la especiación antes de que ocurra la divergencia ecológica. Este conservadurismo de nicho desafía las teorías evolutivas.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- Ecología Ecología Ecología.
- La biogeografía es la biogeografía.
Sus antecedentes:
- Los modelos teóricos predicen una diferenciación limitada de nicho ecológico entre especies estrechamente relacionadas en escalas de tiempo evolutivas.
- La evidencia empírica para el conservadurismo de nicho a largo plazo es escasa, particularmente en diversos taxones.
Objetivo del estudio:
- Investigar el conservadurismo de nicho ecológico en taxones hermanos de aves, mamíferos y mariposas durante millones de años.
- Para probar si el conservadurismo de nicho difiere a nivel de la especie frente al nivel de la familia.
Principales métodos:
- Se construyeron modelos de nicho ecológico para pares de taxones hermanos en el sur de México.
- Se utilizaron predicciones geográficas recíprocas para evaluar la superposición y divergencia de nichos.
- El análisis incluyó aves, mamíferos y mariposas.
Principales resultados:
- Se observó un conservadurismo de nicho significativo a nivel de especie durante varios millones de años de evolución independiente.
- Se detectó un pequeño conservadurismo de nicho a nivel familiar.
- Los taxones hermanos exhibieron nichos ecológicos estables a pesar de la separación geográfica.
Conclusiones:
- La especiación ocurre principalmente a lo largo de dimensiones geográficas, no ecológicas, durante largos períodos evolutivos.
- Las diferencias ecológicas entre las especies tienden a evolucionar después de los eventos de especiación.
- El conservadurismo de nicho proporciona un marco para comprender los patrones de diversificación.
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