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Aim: Humans influence species distributions by modifying the environment and by dispersing species beyond their natural ranges. Populations of species that have established in disjunct regions of the world may exhibit trait differentiation from native populations due to founder effects and adaptations to selection pressures in each distributional region. We compared multiple native, expansive and introduced populations of a single species across the world, considering the influence of environmental stressors and transgenerational effects. Location: United States Gulf and Atlantic coasts, United States interior, European Atlantic and Mediterranean coasts, east coast of Australia. Taxon: Baccharis halimifolia L. (eastern baccharis). Methods: We monitored seed germination, seedling emergence, survival and early growth in a common garden experiment, conducted with over 18,200 seeds from 80 populations. We also evaluated the influence of environmental stress and maternal traits on progeny performance. Results: Introduced European Atlantic populations had faster germination and early growth than native populations. However, this was not the case for the more recently naturalized European Mediterranean populations. Introduced Australian populations grew faster than native populations in non-saline environments but had lower survival in saline conditions commonly encountered in the native range. Similarly, expansive inland US populations germinated faster than coastal native populations in non-saline environments but grew and germinated more slowly in saline environments. Maternal inflorescence and plant size were positively related with seed germination and seedling survival, whereas flower abundance was positively correlated with seedling early growth and survival. However, maternal traits explained a much lower fraction of the total variation in early demographic stages of B. halimifolia than did distributional range. Main conclusions: Phenotypic differentiation could allow B. halimifolia to adapt to different biotic and abiotic selection pressures found in each distributional range, potentially contributing to its success in introduced and expansive ranges.

Summary Increased protein intake by adults typically enhances reproduction and shortens life, but much less is known about the effects of protein intake prior to reproductive maturity. In particular, it remains unclear whether dietary protein mediates a trade-off between survival and the development of reproductive traits, especially in males. We used the nutritional geometry approach to investigate the effects of 25 replicated larval diets varying in protein and carbohydrate content on larval performance and the development of adult male morphology in the neriid fly Telostylinus angusticollis. We found that body size increased with carbohydrate and especially protein content in the larval diet. Moreover, after controlling for body size, dietary protein strongly enhanced the expression of those male morphological traits that appear to be most directly targeted by sexual selection, while having no effect on the expression of other traits. In sharp contrast, egg-to-adult viability decreased steeply with increasing protein content. Thus, protein intake during the larval stage mediates a trade-off between the expression of male secondary sexual traits and the probability of survival to adult emergence.