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Procedure for Adaptive Laboratory Evolution of Microorganisms Using a Chemostat

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Published on: September 20, 2016

Variación en la reversibilidad de la evolución.

H Teotónio¹, M R Rose

¹Department of Ecology and Evolutionary Biology, University of California, Irvine 92612, USA. ht227@cam.ac.uk

|December 2, 2000

Resumen

La evolución adaptativa puede revertirse en las moscas de la fruta, pero no lo hace.

Área de la Ciencia:

Biología evolutiva Biología evolutiva.
Genética de poblaciones genética de poblaciones.

Sus antecedentes:

Se debate la reversibilidad de la evolución adaptativa, con estudios microbianos que arrojan resultados mixtos.
La evolución inversa en las poblaciones sexuales sigue siendo poco estudiada a pesar de las posibles diferencias con las poblaciones asexuales.

Objetivo del estudio:

Para investigar la reversibilidad de la evolución adaptativa en poblaciones de reproducción sexual de Drosophila melanogaster.
Para determinar si la historia evolutiva anterior influye en la tasa y la ocurrencia de la evolución inversa.

Principales métodos:

25 poblaciones divergentes de Drosophila melanogaster fueron devueltas a un entorno ancestral común.
Estas poblaciones se mantuvieron durante 50 generaciones para observar los cambios evolutivos.

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Principales resultados:

Se observó la evolución inversa de vuelta al estado ancestral, pero no fue universal en todas las poblaciones.
El éxito de la evolución inversa dependía del carácter específico y la historia evolutiva previa de la población.
Las poblaciones híbridas no mostraron una mayor propensión a la evolución inversa, lo que indica que la variación genética no fue el principal factor limitante.

Conclusiones:

La evolución inversa adaptativa es un proceso contingente en los organismos que se reproducen sexualmente.
Solo 50 generaciones de reproducción sexual fueron suficientes para que algunas poblaciones experimentaran la evolución inversa, pero no todas.