15 research outputs found
Female data
Data on weight, performance etc. for female beetles. See supplementary information for details of the analysis
Male data
Performance, weight etc. data for male beetles. See supplementary information for full details of the analysis
Within- and Trans-Generational Effects of Variation in Dietary Macronutrient Content on Life-History Traits in the Moth <i>Plodia interpunctella</i>
<div><p>It is increasingly clear that parental environment can play an important role in determining offspring phenotype. These “transgenerational effects” have been linked to many different components of the environment, including toxin exposure, infection with pathogens and parasites, temperature and food quality. In this study, we focus on the latter, asking how variation in the quantity and quality of nutrition affects future generations. Previous studies have shown that artificial diets are a useful tool to examine the within-generation effects of variation in macronutrient content on life history traits, and could therefore be applied to investigations of the transgenerational effects of parental diet. Synthetic diets varying in total macronutrient content and protein: carbohydrate ratios were used to examine both within- and trans-generational effects on life history traits in a generalist stored product pest, the Indian meal moth <i>Plodia interpunctella</i>. The macronutrient composition of the diet was important for shaping within-generation life history traits, including pupal weight, adult weight, and phenoloxidase activity, and had indirect effects via maternal weight on fecundity. Despite these clear within-generation effects on the biology of <i>P</i>. <i>interpunctella</i>, diet composition had no transgenerational effects on the life history traits of offspring. <i>P</i>. <i>interpunctella</i> mothers were able to maintain their offspring quality, possibly at the expense of their own somatic condition, despite high variation in dietary macronutrient composition. This has important implications for the plastic biology of this successful generalist pest.</p></div
Supplementary material from The effect of sexual selection on adaptation and extinction under increasing temperatures
Strong sexual selection has been reported to both enhance and hinder the adaptive capacity and persistence of populations when exposed to novel environments. Consequently, how sexual selection influences population adaption and persistence under stress remains widely debated. Here, we present two empirical investigations of the fitness consequences of sexual selection on populations of the Indian meal moth, <i>Plodia interpunctella,</i> exposed to stable or gradually increasing temperatures. When faced with increasing temperatures, strong sexual selection was associated with both increased fecundity and offspring survival compared with populations experiencing weak sexual selection, suggesting sexual selection acts to drive adaptive evolution by favouring beneficial alleles. Strong sexual selection did not, however, delay extinction when the temperature became excessively high. By manipulating individuals' mating opportunities during fitness assays, we were able to assess the effect of multiple mating independently from the effect of population-level sexual selection, and found that polyandry has a positive effect on both fecundity and offspring survival under increasing temperatures in those populations evolving with weak sexual selection. Within stable temperatures, there were some benefits from strong sexual selection but these were not consistent across the entire experiment, possibly reflecting changing costs and benefits of sexual selection under stabilizing and directional selection. These results indicate that sexual selection can provide a buffer against climate change and increase adaptation rates within a continuously changing environment. These positive effects of sexual selection may, however, be too small to protect populations and delay extinction when environmental changes are relatively rapid
Path diagrams for the final models explaining the relationship between female (A) and male (B) adult fat content, testes mass (males only) and larval nutrition, adult morphology and post-eclosion weight gain.
<p>Solid lines indicate positive relationships, dashed lines negative, double headed arrows indicate correlation (i.e. no assumptions about causality) and line width is proportional to the strength of the relationship. Numbers next to arrows indicate regression or correlation coefficients calculated from standardized predictor variables.</p
Effects of within-generation and transgenerational variation in dietary macronutrients on phenoloxidase vmax.
<p>The interaction between total macronutrient content (protein and carbohydrates combined) and sex shaped the response of phenoloxidase activity to diet composition in the within-generation experiment (left panel). There were, however, no transgenerational effects of maternal diet composition (right panel). Black bars: males, grey bars: females; X axis labels refer to diet composition, e.g. 3H = 30% cellulose, high protein, 5L = 50% cellulose, low protein; error bars are 95% confidence intervals.</p
Effects of within-generation and transgenerational variation in dietary macronutrients on adult weight.
<p>A three way interaction between total macronutrient content, P:C ratio, and sex shaped the response of adult weight to diet composition in the within-generation experiment (left panel). There were no transgenerational effects of maternal diet composition (right panel). Black bars: males, grey bars: females; X axis labels refer to diet composition, e.g. 3H = 30% cellulose, high protein, 5L = 50% cellulose, low protein; error bars are 95% confidence intervals.</p
Supplementary information for Knell and MartĂnez 2017 from Selective harvest focused on sexual signal traits can lead to extinction under directional environmental change
Contains supplementary results, a full description of the model and the model code
ESM titles from The effect of sexual selection on adaptation and extinction under increasing temperatures
Strong sexual selection has been reported to both enhance and hinder the adaptive capacity and persistence of populations when exposed to novel environments. Consequently, how sexual selection influences population adaption and persistence under stress remains widely debated. Here, we present two empirical investigations of the fitness consequences of sexual selection on populations of the Indian meal moth, <i>Plodia interpunctella,</i> exposed to stable or gradually increasing temperatures. When faced with increasing temperatures strong sexual selection was associated with both increased fecundity and offspring survival compared with populations experiencing weak sexual selection, suggesting sexual selection acts to drive adaptive evolution by favouring beneficial alleles. Strong sexual selection did not, however, delay extinction when the temperature became excessively high. By manipulating individuals' mating opportunities during fitness assays, we were able to assess the effect of multiple mating independently from the effect of population-level sexual selection, and found that polyandry has a positive effect on both fecundity and offspring survival under increasing temperatures in those populations evolving with the weak sexual selection. Within stable temperatures, there were some benefits from strong sexual selection but these were not consistent across the entire experiment, possibly reflecting changing costs and benefits of sexual selection under stabilizing and directional selection. These results indicate that sexual selection can provide a buffer against climate change and increase adaptation rates within a continuously changing environment. These positive effects of sexual selection may, however, be too small to protect populations and delay extinction when environmental changes are relatively rapid
Effects of within-generation and transgenerational variation in dietary macronutrients on haemocyte counts.
<p>There were no within-generation or transgenerational effects of dietary composition on haemocyte count. Left panel: within-generation experiment, right panel: transgenerational experiment; black bars: males, grey bars: females. X axis labels refer to diet composition, e.g. 3H = 30% cellulose, high protein, 5L = 50% cellulose, low protein; error bars are 95% confidence intervals.</p