Browsing by Subject "FEMALES"

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  • Rautiala, Petri; Helantera, Heikki; Puurtinen, Mikael (2019)
    Evolution of altruistic behavior was a hurdle for the logic of Darwinian evolution. Soon after Hamilton formalized the concept of inclusive fitness, which explains how altruism can evolve, he suggested that the high sororal relatedness brought by haplodiploidy could be why Hymenopterans have a high prevalence in eusocial species, and why helpers in Hymenoptera are always female. Later it was noted that in order to capitalize on the high sororal relatedness, helpers would need to direct help toward sisters, and this would bias the population sex ratio. Under a 1:3 males:females sex ratio, the inclusive fitness valuation a female places on her sister, brother, and an own offspring are equalapparently removing the benefit of helping over independent reproduction. Based on this argumentation, haplodiploidy hypothesis has been considered a red herring. However, here we show that when population sex ratio, cost of altruism, and population growth rate are considered together, haplodiploidy does promote female helping even with female-biased sex ratio, due the lowered cost of altruism in such populations. Our analysis highlights the need to re-evaluate the role of haplodiploidy in the evolution of helping, and the importance of fully exploring the model assumptions when comparing interactions of population sex ratios and social behaviors.
  • ARISE Investigators; Luethi, Nora; Bailey, Michael; Harjola, V-P; Okkonen, M.; Pettilä, V.; Sutinen, E.; Wilkman, E. (2020)
    Purpose: To assess the impact of gender and pre-menopausal state on short- and long-term outcomes in patients with septic shock. Material and methods: Cohort study of the Australasian Resuscitation in Sepsis Evaluation (ARISE) trial, an international randomized controlled trial comparing early goal-directed therapy (EGDT) to usual care in patients with early septic shock, conducted between October 2008 and April 2014. The primary exposure in this analysis was legal gender and the secondary exposure was pre-menopausal state defined by chronological age ( Results: 641 (40.3%) of all 1591 ARISE trial participants in the intention-to-treat population were females and overall, 337 (21.2%) (146 females) patients were 50 years of age or younger. After risk-adjustment, we could not identify any survival benefit for female patients at day 90 in the younger (50 years) age-group (aOR: 1.10 (0.81-1.49), p = .56). Similarly, there was no gender-difference in ICU, hospital, 1-year mortality nor quality of life measures. Conclusions: This post-hoc analysis of a large multi-center trial in early septic shock has shown no short- or long-term survival effect for women overall as well as in the pre-menopausal age-group. (C) 2019 Elsevier Inc. All rights reserved.
  • van Baaren, Joan; Candolin, Ulrika (2018)
    Most insect species are affected by Human Induced Rapid Environmental Changes (HIREC). Multiple responses to HIREC are observed in insects, such as modifications of their morphology, physiology, behavioural strategies or phenology. Most of the responses involve phenotypic plasticity rather than genetic evolution. Here, we review the involvement of behavioural plasticity in foraging, reproduction, habitat choice and dispersal; and how behavioural plasticity modifies social behaviour and inter-specific interactions. Although important, behavioural plasticity is rarely sufficient to cope with HIREC. An increasing number of studies find species to respond maladaptively or insufficiently to various anthropogenic disturbances, and less often is large degree of plasticity linked to success.
  • Xia, Zhichao; He, Yue; Yu, Lei; Lv, Rubing; Korpelainen, Helena; Li, Chunyang (2020)
    Soil phosphorus (P) availability and its distribution influence plant growth and productivity, but how they affect the growth dynamics and sex-specific P acquisition strategies of dioecious plant species is poorly understood. In this study, the impact of soil P availability and its distribution on dioecious Populus cathayana was characterized. P. cathayana males and females were grown under three levels of P supply, and with homogeneous or heterogeneous P distribution. Females had a greater total root length, specific root length (SRL), biomass and foliar P concentration under high P supply. Under P deficiency, males had a smaller root system than females but a greater exudation of soil acid phosphatase, and a higher colonization rate and arbuscular mycorrhizal hyphal biomass, suggesting a better capacity to mine P and a stronger association with arbuscular mycorrhizal fungi to forage P. Heterogeneous P distribution enhanced growth and root length density (RLD) in females. Female root proliferation in P-rich patches was related to increased foliar P assimilation. Localized P application for increasing P availability did not enhance the biomass accumulation and the morphological plasticity of roots in males, but it raised hyphal biomass. The findings herein indicate that sex-specific strategies in P acquisition relate to root morphology, root exudation and mycorrhizal symbioses, and they may contribute to sex-specific resource utilization patterns and niche segregation.