A currently popular hypothesis states that the expression of carotenoid-dependent sexual ornaments and immune function may be correlated because both traits are positively affected by carotenoids. However, such a correlation may arise for another reason: it is well known that immune function is dependent on nutritional condition. A recent study has suggested that the expression of ornaments may...

There is currently much interest in mate preferences for sexual ornaments. However, few studies have focused on individual variation in mate preference despite its importance for the rate and direction of sexual selection. Females of the sexually dimorphic stalk-eyed fly, Diasemopsis meigenii, exhibit an unambiguous rejection response towards unattractive males bearing small ornaments. We inves...

Theory predicts that physiological costs of producing elaborate phenotypes assure the honesty of sexually selected traits. It is generally assumed that these physiological processes drive sexually selected displays. However, a recent study by Safran and colleagues demonstrates that the manipulation of plumage ornaments in barn swallows alters the temporal course of circulating androgens, thus r...

Ornaments are a way to describe changes in datatype definitions that preserve their recursive structure, reorganizing, adding, or dropping some pieces of data so that functions operating on the bare definition can be partially and sometimes totally lifted into functions operating on the ornamented structure. We propose an extension of ML with higherorder ornaments. We introduce a meta-language ...

In this article we outline a method that automatically transforms an Euclidean ornament into a hyperbolic one. The necessary steps are pattern recognition, symmetry detection, extraction of a Euclidean fundamental region, conformal deformation to a hyperbolic fundamental region and tessellation of the hyperbolic plane with this patch. Each of these steps has its own mathematical subtleties that...