Soft selection and quantitative genetic variation: a laboratory experiment

ABSTRACT The effect of environmental heterogeneity on the genetic variation of different quantitative characters was studied in two laboratory and two recently captured populations of

_Drosophila melanogaster_. Two different culture media (habitats R and G) were used. Coarse-grained heterogeneity with independent density control in each habitat (R + G), and fine-grained

(R/G) heterogeneity were simulated in population cages. Control populations in both R and G habitats were also maintained. Genetic differences for oviposition-site preference, larval

preference and/or within-habitat viability were found between subpopulations sampled from different media. This happened in all four populations maintained on R + G, two populations

maintained on R/G, and one control population. Thus, environmental heterogeneity seems to protect genetic variability responsible for between-habitat genetic differentiation, particularly

when such heterogeneity corresponds to the ‘soft selection’ model (R + G). However, for the quasi-neutral trait sternopleural bristle number, no genetic between-habitat differentiation, nor

increased heritability were observed in populations maintained under any kind of environmental heterogeneity. Hence, although soft selection seems to be a real force in determining

adaptation to heterogeneous environments, the genetic variability maintained may be small in relation to the whole genome. SIMILAR CONTENT BEING VIEWED BY OTHERS EXPERIMENTAL DATA SUGGEST

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helpful comments, and to an anonymous referee for careful notes which greatly improved the manuscript. This work was supported by a CICYT grant (No. PB86-0017). AUTHOR INFORMATION AUTHORS

AND AFFILIATIONS * Departemento de Genética, Facultad de Biologia, Universidad Complutense, Madrid, 28040, Spain Aurora García-Dorado, Paloma Martin & Nieves García Authors * Aurora

García-Dorado View author publications You can also search for this author inPubMed Google Scholar * Paloma Martin View author publications You can also search for this author inPubMed 

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THIS ARTICLE García-Dorado, A., Martin, P. & García, N. Soft selection and quantitative genetic variation: a laboratory experiment. _Heredity_ 66, 313–323 (1991).

https://doi.org/10.1038/hdy.1991.40 Download citation * Received: 04 July 1990 * Issue Date: 01 June 1991 * DOI: https://doi.org/10.1038/hdy.1991.40 SHARE THIS ARTICLE Anyone you share the

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Nature SharedIt content-sharing initiative KEYWORDS * environmental heterogeneity * selection * soft selection