A TEST FOR THE GENETIC BASIS OF NATURAL SELECTION: AN INDIVIDUAL-BASED LONGITUDINAL STUDY IN A STREAM-DWELLING FISH
Article first published online: 24 DEC 2010
© 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.
Volume 65, Issue 4, pages 1037–1047, April 2011
How to Cite
Morrissey, M. B. and Ferguson, M. M. (2011), A TEST FOR THE GENETIC BASIS OF NATURAL SELECTION: AN INDIVIDUAL-BASED LONGITUDINAL STUDY IN A STREAM-DWELLING FISH. Evolution, 65: 1037–1047. doi: 10.1111/j.1558-5646.2010.01200.x
- Issue published online: 4 APR 2011
- Article first published online: 24 DEC 2010
- Accepted manuscript online: 26 NOV 2010 05:09AM EST
- Received June 11, 2010, Accepted October 20, 2010
- genetic covariance;
- Robertson-Price identity;
- selection response
In addition to the well-studied evolutionary parameters of (1) phenotype-fitness covariance and (2) the genetic basis of phenotypic variation, adaptive evolution by natural selection requires that (3) fitness variation is effected by heritable genetic differences among individuals and (4) phenotype-fitness covariances must be, at least in part, underlain by genetic covariances. These latter two requirements for adaptive evolutionary change are relatively unstudied in natural populations. Absence of the latter requirements could explain stasis of apparently directionally selected heritable traits. We provide complementary analyses of selection and variation at phenotypic and genetic levels for juvenile growth rate in brook charr Salvelinus fontinalis in Freshwater River, Newfoundland, Canada. Contrary to the vast majority of reports in fish, we found very little viability selection of juvenile body size. Large body size appears nonetheless to be selectively advantageous via a relationship with early maturity. Genetic patterns in evolutionary parameters largely reflected phenotypic patterns. We have provided inference of selection based on longitudinal data, which are uncommon in high fecundity organisms. Furthermore we have provided a practicable framework for further studies of the genetic basis of natural selection.