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LONG‐TERM LABORATORY EVOLUTION OF A GENETIC LIFE‐HISTORY TRADE‐OFF IN DROSOPHILA MELANOGASTER . 1. THE ROLE OF GENOTYPE‐BY‐ENVIRONMENT INTERACTION
Author(s) -
Leroi Armand M.,
Chippindale Adam K.,
Rose Michael R.
Publication year - 1994
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.1558-5646.1994.tb05309.x
Subject(s) - fecundity , biology , longevity , life history theory , adaptation (eye) , trade off , drosophila melanogaster , reproduction , experimental evolution , drosophila (subgenus) , life history , evolutionary biology , ecology , zoology , demography , genetics , population , gene , neuroscience , sociology
Trade‐offs among life‐history traits are often thought to constrain the evolution of populations. Here we report the disappearance of a trade‐off between early fecundity on the one hand, and late‐life fecundity, starvation resistance, and longevity on the other, over 10 yr of laboratory selection for late‐life reproduction. Whereas the selected populations showed an initial depression in early‐life fecundity, they later converged upon the controls and then surpassed them. The evolutionary loss of the trade‐off among life‐history traits is considered attributable to the following factors: (1) the existence of differences in the culture regimes of the short‐ and long‐generation populations other than the demographic differences deliberately imposed; (2) adaptation of one or both of these sets of populations to the unique aspects of their culture regimes; (3) the existence of an among‐environment trade‐off in the expression of early fecundity in the two culture regimes, as reflected in assays that mimic those regimes. The trade‐off between early and late‐life reproductive success, as manifest among divergently selected populations, is apparent or not depending on the assay environment. This demonstration that strong genotype‐by‐environment interactions can obscure a fundamental trade‐off points to the importance of controlling all aspects of the culture regime of experimental populations and the difficulty of doing so even in the laboratory.