Developmental constraints and wing shape variation in natural populations of Drosophila melanogaster

Abstract

The body sizes and shapes of poikilothermic animals generally show clinal variation with latitude. Among the environmental factors responsible for the dine, temperature seems to be the most probable candidate. In the present work we analysed natural populations of Drosophila melanogaster collected at different geographical localities to determine whether the same selective forces acting on wing development in the laboratory are also at work in the wild. We show that the temperature selection acting on wing development in the laboratory is only one of the selective forces operating in the wild. The size differences between natural populations seem to depend exclusively on cell number whereas they depend on cell area in the laboratory. The two wing compartments behave as distinct units of selection subjected to different genetic control, confirming our previous observations on laboratory populations. In addition, subunits of development defined as regions of cell proliferation centres restricted within longitudinal veins can, in turn, be considered as subunits of selection. Their interaction during development and continuous natural selection around an optimum could explain the high wing shape stability generally found in natural populations.

The Pattern of Variation in Centipede Segment Number as an Example of Developmental Constraint in Evolution

“…Nevertheless, it is also true that this concept has almost never had an in#uence on the main stream of research that was done by neo-Darwinists.'' There are now some signs that the situation may be changing: see the recent work of Guerra et al (1997) and Pezzoli et al (1997).…”

Genetic architecture of wing morphology in Drosophila simulans and an analysis of temperature effects on genetic parameter estimates

“…These compartments reflect the allocation of cells in early development, and their boundary lies right above the fourth longitudinal vein (García-Bellido et al, 1973). Some studies using selection experiments have considered that these compartments are independent subunits of wing development and that they represent separate units of selection subjected to differing genetic control (Cavicchi et al, 1991;Pezzoli et al, 1997). However, Thompson and Woodruff (1982) compared selection responses and hypothesized that 'though some modifiers had strictly vein-specific action, others acted upon all veins in the posterior compartment or upon all veins in the wing'.…”

Morphological Integration Between Developmental Compartments in the Drosophila Wing

“…The subdivision of fly wings into anterior and posterior compartments ( Fig. Accordingly, a number of studies have used morphometric approaches to examine whether anterior and posterior wing compartments are distinct as modules that are reflected in phenotypic and genetic variation (Cavicchi et al 1981(Cavicchi et al , 1985(Cavicchi et al , 1991Thompson and Woodruff 1982;Cowley and Atchley 1990;Guerra et al 1997;Pezzoli et al 1997;Baylac and Penin 1998). Accordingly, a number of studies have used morphometric approaches to examine whether anterior and posterior wing compartments are distinct as modules that are reflected in phenotypic and genetic variation (Cavicchi et al 1981(Cavicchi et al , 1985(Cavicchi et al , 1991Thompson and Woodruff 1982;Cowley and Atchley 1990;Guerra et al 1997;Pezzoli et al 1997;Baylac and Penin 1998).…”