Signal and reward in wild fleshy fruits : does fruit scent predict nutrient content?

The study examines the relationship between olfactory signals and nutrient rewards in 28 fruiting plant species in Madagascar. Previous work has shown that lemurs are the main seed dispersers in the ecosystem, relying on fruit scent to identify ripe fruits. The relative amounts of four chemical classes in fruit scent are measured using gas chromatography and mass spectrometry, as well as the relative amounts of sugar and protein in fruit pulp. The project tests the phylogenetic signal to examine whether closely related taxa tend to be similar, and compares the nutritional content of lemur‐ and bird‐dispersed fruits. The relationships reported here are across species, not within them

The screen test 1915–1930:how stars were born

This article examines the emergence of the screen test as a cultural phenomenon during the silent era in the US and Europe and its role in the development of the star system. The lore that grew up around the screen test almost from its inception held out the possibility for members of the public to cross a threshold into the rarefied world of celebrity. The screen test itself is situated in the liminal space not only between audience and actor, but also between fiction and non-fiction, Europe and Hollywood, the silent era and the talkies, and the public and private spheres. In order to trace the ways in which the screen test as such was narrativized and conceptualized in its foundational stages, this article will analyse accounts from Hollywood and European fan magazines of the silent era, including articles, short fiction, and early cinema apocrypha. The article culminates in a discussion of the film Prix de Beauté / Beauty Prize (Augusto Genina, 1930), which starred Louise Brooks, herself a transnational film icon whose film career spanned the divide between Hollywood and Europe. The film’s final scene, in which a beauty queen is shot dead by her jealous husband as she watches a screen test of herself, has been invoked by a number of film scholars as an allegory of the work performed by cinema, which preserves and disseminates the image of the star far beyond the actor’s physical presence. Speaking to historical conditions of star-making while also capturing its resonance in cultural mythology, the conclusion of Prix de Beauté allows us to consider the origins and functions of screen test discourse itself

Frugivores and the evolution of fruit colour

The study used a comparative community approach, and tested whether distributions of fruit colours are consistent with the hypothesis that colour is an evolved signal to seed dispersers. The contrast between ripe fruits and leaf backgrounds are compared at two sites, one in Madagascar where seed dispersers are primarily night-active (red–green colour-blind lemurs), and the other in Uganda, where most vertebrate seed dispersers are day-active primates and birds with greater capacity for colour vision. Results indicate that fruit colour has evolved to contrast against background leaves in response to the visual capabilities of local seed disperser communities.German Science Foundation grant (NE 2156/1-1)NSERC CanadaThe CRC progra

The evolution of fruit colour : phylogeny, abiotic factors and the role of mutualists

The study employs an integrative multivariate approach which successfully examines what drives variation in fruit colour. It used phylogenetically controlled models to estimate the roles of phylogeny, abiotic factors, and dispersal mode on fruit colour variation. The effects of animal selection on fruit colour are often difficult to identify. However, the study findings demonstrate that fruit colour is affected by both animal sensory ecology and abiotic factors. Fruit reflection in the ultraviolet area of the spectrum is strongly correlated with leaf reflectance, but it does not correlate with leaf colour in the visible spectrum, thus emphasizing the role of abiotic factors in determining fruit colour.German Science Foundation grantNSERC CanadaThe CRC progra

The evolution of fruit scent: phylogenetic and developmental constraints

Abstract Background Fruit scent is increasingly recognized as an evolved signal whose function is to attract animal seed dispersers and facilitate plant reproduction. However, like all traits, fruit scent is likely to evolve in response to conflicting selective pressures and various constraints. Two major constraints are (i) phylogenetic constraints, in which traits are inherited from ancestors rather than adapted to current conditions and (ii) developmental constraints, if phenotypes are limited by the expression of other traits within the individual. We tested whether phylogenetic constraints play a role in fruit scent evolution by calculating the phylogenetic signal in ripe fruits of 98 species from three study sites. We then estimated the importance of developmental constraints by examining whether ripe fruits tend to emit compounds that are chemically similar to, and share biosynthetic pathways with, compounds emitted by conspecific unripe fruits from which they develop. Results We show that closely related taxa are not more similar to each other than to very distinct taxa, thus indicating that fruit scent shows little phylogenetic signal. At the same time, although ripe and unripe fruits of the same species tend to emit different chemicals, they tend to employ chemicals originating from similar biosynthetic pathways, thus indicating that some developmental constraints determine ripe fruit scent. Conclusions Our results highlight the complex landscape in which fruit scent has evolved. On one hand, fruit scent evolution is not limited by common ancestry. On the other hand, the range of chemicals that can be employed in ripe fruits is probably constrained by the needs of unripe fruits