Sexual selection has repeatedly been shown to be the probable driving force behind the positive Darwinian evolution of genes affecting male reproductive success. Here we compare the sequence evolution of the sperm ligand zonadhesin with body mass dimorphism in primates. In contrast to previous related studies, the present approach takes into account not only catarrhine primates, but also platyr...

Faces are complex visual objects, and faces chosen to vary in 1 regard may unintentionally vary in other ways, particularly if the correlation is a property of the population of faces. Here, we present an example of a correlation that arises from differences in the degree of sexual dimorphism. In Experiment 1, paired similarity ratings were collected for a set of 40 real face images chosen to v...

Gene expression differences between the sexes account for the majority of sexually dimorphic phenotypes, and the study of sex-biased gene expression is important for understanding the genetic basis of complex sexual dimorphisms. However, it has been difficult to test the nature of this relationship due to the fact that sexual dimorphism has traditionally been conceptualized as a dichotomy betwe...

we investigated sexual size dimorphism in the tree frog, hyla savignyi using 33 males and 22 females from the western and northwestern regions of kermanshah province, western iran. out of sixteen measured morphometric characters, four were significantly larger in females than in males. these characters were nostrileye length, brachium length, elbowlongest finger length and hind limb length.

This study estimated the magnitude of sexual dimorphism in a relict sheep from Catalunya (NE Spain), called Fardasca,using geometric morphometric techniques. For these analyses, a total of 18 skull specimens (2 adult males and 16 females) were studied. Our results suggest that the breed is not cranially dimorphic, so sex determination using landmarks described here as criteria is likely to yiel...

Sexual dimorphisms vary widely among species. This variation must arise through sex-specific evolutionary modifications to developmental processes. Anolis lizards vary extensively in their expression of cranial dimorphism. Compared with other Anolis species, members of the carolinensis clade have evolved relatively high levels of cranial dimorphism; males of this clade have exceptionally long f...

In human females cyclic shifts in preference have been documented for odour and physical and behavioral male traits. Women prefer the smell of dominant males, more masculine male faces and men behaving more dominantly when at peak fertility than at other times in their menstrual cycle. Here we examine variation in preferences for body sexual dimorphism. Across two studies, both between- and wit...

Size sexual dimorphism occurs in almost all mammals. In Portuguese Water Dogs, much of the difference in skeletal size between females and males is due to the interaction between a Quantitative Trait Locus (QTL) on the X-chromosome and a QTL linked to Insulin-like Growth Factor 1 (IGF-1) on the CFA 15 autosome. In females, the haplotype of CFA 15 resulting in small size is dominant. In males, t...

Sexual size dimorphism (SSD) is often affected by environmental conditions, but the effect of temperature on SSD in ectotherms still requires rigorous investigation. We compared the plastic responses of size-at-maturity to temperature between males and females within 85 diverse arthropod species, in which individuals of both sexes were reared through ontogeny under identical conditions with exc...