|Incipient speciation driven by phenotypic plasticity? Evidence from sympatric populations of Arctic charr|
Adams, C.E.; Huntingford, F. (2004). Incipient speciation driven by phenotypic plasticity? Evidence from sympatric populations of Arctic charr. Biol. J. Linn. Soc. 81(4): 611-618
In: Biological Journal of the Linnean Society. Academic Press: London; New York. ISSN 0024-4066, more
Evolution; Morphometry; Phenotypic variations; Polymorphism; Polymorphism; Marine
|Authors|| || Top |
- Adams, C.E.
- Huntingford, F.
Recent models suggest that the existence of environmentally induced polymorphisms within a single population (especially those related to foraging) facilitates the process of evolutionary divergence within a single gene pool by generating distinct phenotypic modes that are exposed to differential selection. In order to test a prediction of the phenotypic plasticity model of divergence, we used a well-documented polymorphism to disentangle the relative effects of morph and rearing environment in generating phenotypic variance. We reared first-generation offspring of two sympatric morphs of Arctic charr Salvelinus alpinus in the laboratory and compared their head morphology with that of their wild parents. Morphological characters with a known functional role in foraging were highly plastic. Rearing environment accounted for the largest component of the variation in expressed phenotype, but this environmental effect overlaid a clear (but small) genetic effect. We conclude that phenotypic plasticity has played a significant role in the evolution of this trophic polymorphism, but that the evolutionary process has progressed to the point that the gene pool is now segregated.