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The evolutionary history of Drosophila buzzatii. XX. Positive phenotypic covariance between field adult fitness components and body size
Author(s) -
Santos Mauro,
Ruiz Alfredo,
QuezadaDíaz Jorge E.,
Barbadilla Antonio,
Fontdevila Antonio
Publication year - 1992
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1046/j.1420-9101.1992.5030403.x
Subject(s) - biology , mating , fecundity , assortative mating , natural selection , zoology , life history theory , evolutionary biology , population , ovariole , natural population growth , trait , selection (genetic algorithm) , ecology , genetics , life history , demography , sociology , oocyte , embryo , computer science , programming language , artificial intelligence
In the cactophilic species Drosphila buzzatii, it is feasible to infer the action of natural selection by simultaneously sampling different life history stages in the field. During four years of research, samples of mating and non‐mating adults and pupae were taken from a natural population. The main adult fitness components, i.e., mating success, longevity, and fecundity, were recorded in relation to body size, as measured by thorax length. The age of flies was estimated by observing the developmental stage of the reproductive system. Our data showed that larger flies can outlive and outmate small flies, and that mating success is related to age. An estimate of the fitness function showed a linear increase of mating success with increasing thorax length. There was no assortative mating for this trait. We advance the hypothesis that mating success is related to the rate of encounter and courtship time through general activity, which in turn may be related to body size. A positive phenotypic correlation between thorax length and ovariole number, which is related to fecundity, was found in females emerged from wild pupae. Neither the phenotypic nor the genetic (additive) correlations between these two traits were statistically different from zero in laboratory reared females. The genetic consequences of the observed phenotypic selection on body size are discussed.