RELATIVE ROLE OF GENETIC DETERMINATION AND PLASTIC RESPONSE DURING ONTOGENY FOR SHELL-SHAPE TRAITS SUBJECTED TO DIVERSIFYING SELECTION

Authors

  • Paula Conde-Padín,

    1. ECIMAT, Illa de Toralla 36331 Vigo, Spain
    2. Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Campus de Vigo 36310, Vigo, Spain
    Search for more papers by this author
  • Armando Caballero,

    1. Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Campus de Vigo 36310, Vigo, Spain
    Search for more papers by this author
  • Emilio Rolán-Alvarez

    1. Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Campus de Vigo 36310, Vigo, Spain
    2. E-mail: rolan@uvigo.es
    Search for more papers by this author

Abstract

We studied the relative role of genetic determination versus plastic response for traits involved in ecological adaptation of two ecotypes of Littorina saxatilis living at different shore levels. To investigate the magnitude of the plastic response across ontogeny, we compared morphological data from individuals grown in the laboratory and taken from the wild at three developmental stages: shelled embryos, juveniles, and adults. The results indicate that most shell shape variation (72–99%) in adaptive traits (globosity and aperture of the shell) is explained by the ecotype irrespective of the growth environment, suggesting that direct genetic determination is the main factor responsible for the process of adaptation in the wild. There was a tendency for the contribution of plasticity to increase over ontogeny but, in general, the direction of the plastic response did not suggest that this was adaptive.

Ancillary