Sex in a material world: why the study of sexual reproduction and sex-specific traits should become more nutritionally-explicit

Abstract

International audienceRecent advances in nutritional ecology, particularly arising from Ecological stoichiometry and the Geometric framework for nutrition, have resulted in greater theoretical coherence and increasingly incisive empirical methodologies that in combination allow for the consideration of nutrient-related processes at many levels of biological complexity. However, these advances have not been consistently integrated into the study of sexual differences in reproductive investment, despite contemporary emphasis on the material costs associated with sexually selected traits (e.g. condition-dependence of exaggerated ornaments). Nutritional ecology suggests that material costs related to sex-specific reproductive traits should be linked to quantifiable underlying differences in the relationship between individuals of each sex and their foods. Here, we argue that applying nutritionally-explicit thought to the study of sexual reproduction should both deepen current understanding of sex-specific phenomena and broaden the tractable frontiers of sexual selection research. In support of this general argument, we examine the causes and consequences of sex-specific nutritional differences, from food selection and nutrient processing to sex-specific reproductive traits. At each level of biological organization, we highlight how a nutritionally-explicit perspective may provide new insights and help to identify new directions. Based on predictions derived at the individual level, we then consider how sex-specific nutrient limitation might influence population growth, and thus potentially broader patterns of life history evolution, using a simple population dynamics model. We conclude by highlighting new avenues of research that may be more accessible from this integrative perspective

Sex and size matter: ontogenetic patterns of nutrient content of aquatic insects

“…Veldboom and Haro (2011) found 2 populations of Brachycentrus in which male pupae were more enriched in P than female pupae, and 2 populations where the %P was equal between pupae of both sexes. Morehouse et al (2010) suggested that sexual differences in nutrient content should be expected based on difference in biochemical demand and composition of gametes and other sexually specific structures.…”

Can resource costs of polyploidy provide an advantage to sex?

“…Two main frameworks-the Geometric Framework of Nutrition (Raubenheimer et al, 2009;Simpson and Raubenheimer, 2012), which focuses on biochemicals (mainly protein, carbohydrates and lipids), and Ecological Stoichiometry (Sterner and Elser, 2002), which focuses on ratios of elements (mainly carbon, nitrogen and phosphorus)-have been developed to explore the interactive effects of multiple dietary components on organism performance. Some areas of emphasis in this research are that (1) dietary nutritional imbalances provide distinct challenges for organisms depending on the nature of the imbalance (Kay et al, 2005) (2) scarcities of particular nutrients can affect trait expression in specific ways (Morehouse et al, 2010) and (3), the relative availability of nutrients can influence the nature and dynamics of competitive and other species interactions (Moe, 2005).…”

The Cost of Mating: Influences of Life History Traits and Mating Strategies on Lifespan in Two Closely RelatedYponomeutaSpecies

“…Adult feeding can have important effects on sexspecific mortality rates and sexual behaviour (see also [55]). For example, Pararge aegeria (Satyridae) adults lived longer when fed [56] and in Pseudoplusia includens (Noctuidae), a shortage of food and water led to sex-specific lifespan in a population in which males normally live as long as females [57].…”