Premium
ENVIRONMENT SPECIFIC PLEIOTROPY FACILITATES DIVERGENCE AT THE ECTODYSPLASIN LOCUS IN THREESPINE STICKLEBACK
Author(s) -
Barrett Rowan D. H.,
Rogers Sean M.,
Schluter Dolph
Publication year - 2009
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.2009.00762.x
Subject(s) - stickleback , biology , pleiotropy , natural selection , reproductive isolation , evolutionary biology , disruptive selection , allele , locus (genetics) , phenotypic plasticity , ecology , phenotype , genetics , zoology , gene , selection (genetic algorithm) , fish <actinopterygii> , fishery , population , demography , artificial intelligence , sociology , computer science
Adaptive radiation occurs when divergent natural selection in different environments leads to phenotypic differentiation. The pleiotropic effects of underlying genes can either promote or constrain this diversification. Identifying the pleiotropic effects of genes responsible for divergent traits, and testing how the environment influences these effects, can therefore help to provide an understanding of how ecology drives evolutionary change between populations. Positive selection on low‐armor alleles at the Ectodysplasin ( Eda ) locus in threespine stickleback has led to the repeated evolution of reduced armor in populations following freshwater colonization by fully armored marine sticklebacks. Here, we demonstrate that Eda has environmentally determined pleiotropic effects on armor and growth. When raised in freshwater, reduced armor sticklebacks carrying “low” alleles at Eda had increased growth rate relative to fully armored sticklebacks carrying “complete” alleles. In saltwater treatments this growth advantage was present during juvenile growth but lost during adult growth, suggesting that in this environment stickleback are able to develop full armor plates without sacrificing overall growth rate. The environment specific pleiotropic effects of Eda demonstrate that ecological factors can mediate the influence of genetic architecture in driving phenotypic evolution. Furthermore, because size is important for mate choice in stickleback, the growth rate differences influenced by Eda may have effects on reproductive isolation between marine and freshwater populations.