Sexual Selection and the Evolution of Allometry for Sexual Size Dimorphism in the Water Strider, Aquarius remigis

Fine-scale population structure and asymmetrical dispersal in an obligate salt-marsh passerine, the Saltmarsh Sparrow(Ammodramus caudacutus)

“…These differences in mating strategy may drive size differences between male Saltmarsh and Nelson's sparrows. The scramble-competition mating system of the Saltmarsh Sparrow results in male-male competition, which should select for large body sizes (Greenlaw 1993, Andersson 1994, Fairbairn and Preziosi 1994, Székely 2004. By contrast, male Nelson's Sparrows perform frequent flight displays, which should select for a smaller, more acrobatic body size (Székely 2004, Byers et al 2010.…”

Size-Dependent Selection on Arrival Times in Sticklebacks: Why Small Males Arrive First

“…Twenty five samples of D. pratensis were collected at localities from Argentina spanning 22 degrees of latitude and 0 to 2474 m elevation (Fig.1 corresponding mean of males (Smith 1999), in order to visualize directly deviations from 1 (i.e., from isometry). The scaling of SSD with body size was described by regressing log10 (male size) on log10 (female size) for the six traits (Fairbairn & Preziosi 1994;Abouheif & Fairbairn 1997;Fairbairn 1997Fairbairn , 2005. Thus, Rensch`s rule applies when the slope of the regression line is greater than 1.0, whereas slopes smaller than 1.0 signal its converse (Fairbairn 1997).…”

“…In many mammals and birds SSD is male biased, but in the majority of ectotherms, it is female biased, although with many exceptions (Ralls 1976, Andersson 1994, Monnet & Cherry 2002, Schulte-Hostedde et al 2002, Teder & Tammaru 2005. Differences between females and males in the intensity and/or direction of sexual selection can generate differences in SSD (Darwin 1871;Spencer & Masters 1992;Andersson 1994;Fairbairn & Preziosi 1994;Ding & Blanckenhorn 2002;Kraushaar & Blanckenhorn 2002;Szekely et al 2004;Teder & Tammaru 2005, 2005. In most insects, females are larger, perhaps because larger females are more fecund than smaller ones (Andersson 1994, Honek 1993).…”

Proximate Causes of Rensch’s Rule: Does Sexual Size Dimorphism in Arthropods Result from Sex Differences in Development Time?

“…This is equivalent to saying that male body size varies or diverges more over evolutionary time than female body size, irrespective of which sex is larger. While Rensch (1950) did not offer an explanation for this phenomenon, Fairbairn and Preziosi (1994) were the first to hypothesize that sexual selection for large male size may be the primary force driving this allometric pattern in SSD. Since then, some additional evidence for this hypothesis has been published (Abouheif and Fairbairn 1997;Fairbairn 1997;Székely et al 2000Székely et al , 2004Kraushaar and Blanckenhorn 2002;Lindenfors et al 2003), but more studies are clearly needed (Fairbairn 1997).…”

“…Rensch's rule thus refers to a systematic pattern of interspecific (and sometimes, by extension, analogous intraspecific, between-population) variation in SSD (e.g., Fairbairn and Preziosi 1994). For any particular species, which sex is larger depends on whether selection for (primarily fecundity selection in females and sexual selection in males) and against (primarily viability selection) large body size equilibrate differently in the two sexes (the socalled equilibrium model of SSD ;Price 1984;Arak 1988;Travis 1989;Schluter et al 1991;Andersson 1994;Fairbairn 1997;Blanckenhorn 2000).…”