A survey of 117 species of arthropods and 17 species of vertebrates showed a strong trend for male genitalia to have relatively low static allometric values. This trend contrasts with the allometry of other structures under sexual selection, which usually show steep allometric slopes. The trend to low allometric genital values is less consistent in mammals than in arthropods. Data not in accord with the previous the "one-size-fits-all" explanation for low allometric slopes in genitalia, which was based on sexual selection by female choice, suggest a more general version that includes both natural selection and sexual selection, and involves both mechanical fit and stimulation. Less-complete data on the female genitalia of arthropods suggest a trend to similar low allometric slopes, and may also be explained by mechanical fit and stimulatory one-size-fits-all arguments.
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http://dx.doi.org/10.1111/j.1558-5646.2008.00528.x | DOI Listing |
BMC Ecol Evol
January 2025
National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bengaluru, 560065, India.
Background: Trait variation is shaped by functional roles of traits and the strength and direction of selection acting on the traits. We hypothesized that in butterflies, sexually selected colouration is more variable owing to condition-dependent nature and directional selection on sexual ornaments, whereas naturally selected colouration may be less variable because of stabilising selection. We measured reflectance spectra, and extracted colour parameters, to compare the amount of variation in sexually versus naturally selected colour patches across wing surfaces and sexes of 20 butterfly species across 4 families (Nymphalidae, Papilionidae, Pieridae, Lycaenidae).
View Article and Find Full Text PDFCommun Biol
January 2025
Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada.
Species that coexist in hybrid zones sexually isolate through reproductive character displacement, a mechanism that favours divergence between species. In Drosophila, behavioural and physiological traits discourage heterospecific mating between species. Recently, social network analysis revealed flies produce strain-specific and species-specific social structures.
View Article and Find Full Text PDFThe Problem: People use social media platforms to chat, search, and share information, express their opinions, and connect with others. But these platforms also facilitate the posting of divisive, harmful, and hateful messages, targeting groups and individuals, based on their race, religion, gender, sexual orientation, or political views. Hate content is not only a problem on the Internet, but also on traditional media, especially in places where the Internet is not widely available or in rural areas.
View Article and Find Full Text PDFCochrane Database Syst Rev
January 2025
School of Medical Sciences, Department of Metabolism and Systems Science, WHO Collaborating Centre for Global Women's Health Research, University of Birmingham, Birmingham, UK.
Background: Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Accurate diagnosis of PPH can prevent adverse outcomes by enabling early treatment.
Objectives: What is the accuracy of methods (index tests) for diagnosing primary PPH (blood loss ≥ 500 mL in the first 24 hours after birth) and severe primary PPH (blood loss ≥ 1000 mL in the first 24 hours after birth) (target conditions) in women giving birth vaginally (participants) compared to weighed blood loss measurement or other objective measurements of blood loss (reference standards)?
Search Methods: We searched CENTRAL, MEDLINE, Embase, Web of Science Core Collection, ClinicalTrials.
Elife
January 2025
Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands.
Circulating sexual stages of ) can be transmitted from humans to mosquitoes, thereby furthering the spread of malaria in the population. It is well established that antibodies can efficiently block parasite transmission. In search for naturally acquired antibodies targets on sexual stages, we established an efficient method for target-agnostic single B cell activation followed by high-throughput selection of human monoclonal antibodies (mAbs) reactive to sexual stages of in the form of gametes and gametocyte extracts.
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