Biology subjects

Janicke, T.

Publications and source records attributed to Janicke, T..

4 recordsLinked to original sources

bioRxiv2022

Sexual selection moderates heat stress response in males and females

A widespread effect of climate change is the displacement of organisms from their thermal optima. The associated thermal stress imposed by climate change has been argued to have a particularly strong impact on male reproduction but evidence for this postulated sex-specific stress response is equivocal. One important factor that may explain intra- and interspecific variation in stress responses is sexual selection, which is predicted to magnify negative effects of stress. Nevertheless, empirical studies exploring the interplay of sexual selection and heat stress are still scarce. We tested experimentally for an interaction between sexual selection and thermal stress in the red flour beetle Tribolium castaneum by contrasting heat responses in male and female reproductive success between setups of enforced monogamy versus polygamy. We found that polygamy magnifies detrimental effects of heat stress in males but relaxes the observed negative effects in females. Our results suggest that sexual selection can reverse sex differences in thermal sensitivity, and may therefore alter sex-specific selection on alleles associated with heat tolerance. We argue that these findings have important implications for predicting the role of sexual selection for the adaptation to current global warming and increased frequency of extreme climatic events.

evolutionary biology↗

bioRxiv2021

Sexual selection in females across the animal tree of life

The pioneers of sexual selection theory proposed that males are generally eager whereas females are rather coy with respect to mating. This male-centred perspective on sexual selection continues to permeate our perception of sex differences across disciplines. Despite an increased awareness that females also compete for mating partners, we still tend to consider sexual selection in females a rare peculiarity. Here we present meta-analytic evidence from 72 species across a broad range of animal taxa to show that sexual selection in females is widespread and should be considered the norm rather than the exception. Thereby, our results extend our general understanding of sexual reproduction and may contribute to a more balanced perspective of how sexual selection operates in both males and females.

evolutionary biology↗

bioRxiv2021

Sexual selection and sexual size dimorphism in animals

Sexual selection is often considered as a critical evolutionary force promoting sexual size dimorphism (SSD) in animals. However, empirical evidence for a positive relationship between sexual selection on males and male-biased SSD received mixed support depending on the studied taxonomic group and on the method used to quantify sexual selection. Here, we present a meta-analytic approach accounting for phylogenetic non-independence to test how standardized metrics of the opportunity and strength of pre-copulatory sexual selection relate to SSD across a broad range of animal taxa comprising up to 102 effect sizes from 64 species. We found that SSD was correlated with the sex difference in the opportunity for sexual selection but not with the sex difference in the Bateman gradient. These findings suggest that pre-copulatory sexual selection plays a limited role for the evolution of sexual size dimorphism in a broad phylogenetic context.

evolutionary biology↗

bioRxiv2021

Stronger net selection on males across animals

Sexual selection is considered the major driver for the evolution of manifold sex differences. However, the eco-evolutionary dynamics of sexual selection and their role for a populations adaptive potential to respond to environmental change have only recently been explored. Theory predicts that sexual selection promotes adaptation at a low demographic cost only if net selection is stronger on males compared to females. We used a comparative approach to show that net selection is indeed stronger in males in species prone to intense sexual selection. Given that both sexes share the vast majority of their genes, our findings corroborate the notion that the genome is often confronted with a more stressful environment when expressed in males. Collectively, our study supports a long-standing key assumption required for sexual selection to bolster adaptation, and intense sexual selection may therefore enable some species to track environmental change more efficiently. One sentence summaryComparative study finds support for stronger net selection in males.

evolutionary biology↗