Sexual size dimorphism is one of the most striking animal traits, and among terrestrial animals, it is most extreme in certain spider lineages. The most extreme sexual size dimorphism (eSSD) is female biased. eSSD itself is probably an epiphenomenon of gendered evolutionary drivers whose strengths and directions are diverse. We demonstrate that eSSD spider clades are aberrant by sampling randomly across all spiders to establish overall averages for female (6.9 mm) and male (5.6 mm) size. At least 16 spider eSSD clades exist. We explore why the literature does not converge on an overall explanation for eSSD and propose an equilibrium model featuring clade- and context-specific drivers of gender size variation. eSSD affects other traits such as sexual cannibalism, genital damage, emasculation, and monogyny with terminal investment. Coevolution with these extreme sexual phenotypes is termed eSSD mating syndrome. Finally, as costs of female gigantism increase with size, eSSD may represent an evolutionary dead end.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1146/annurev-ento-011019-025032 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Light alters calling-song characteristics in crickets.
J Exp Biol
January 2025
School of Zoology, Tel Aviv University, Tel-Aviv 6997801, Israel.
Communication is crucial for mate choice and thus for the survival and fitness of most species. In the cricket, females choose males according to their calling-song attractiveness and, exhibiting positive phonotaxis they approach the chosen male. Light has been widely reported to induce changes in crickets' daily activity patterns, including the males' stridulation behavior.
View Article and Find Full Text PDFThe perceptual effects of signal components: black sword margins are crucial for signal size discrimination in green swordtails .
Proc Biol Sci
January 2025
Centre for Ecology and Conservation, University of Exeter, Penryn, UK.
The signals that mediate mate choice can be complex, comprising multiple components, and understanding how complex signals evolve under sexual selection has been the focus of much study. However, open questions still remain about the role of the female's sensory and perceptual processes in shaping the evolution of complex signals. Male green swordtails have an elongated caudal fin that comprises colour, length and a black melanic margin; females prefer males with larger bodies, longer swords and complete black sword margins.
View Article and Find Full Text PDFEffects of variable mating opportunity, delay, and male mating experience on the lifespan, female reproductive traits, and offspring traits of Phytoseiulus persimilis (Acari: Phytoseiidae).
Exp Appl Acarol
January 2025
Manaaki Whenua - Landcare Research, 231 Morrin Road, Auckland, 1072, New Zealand.
The balance between mating benefits and costs shapes reproductive strategies and life history traits across animal species. For biological control programs, understanding how mating rates influence life history traits is essential for optimising population management and enhancing predator efficacy. This study investigates the impact of mating opportunity availability, delayed mating, and male mating history (copulation frequency) on the lifespan (both sexes), female reproductive traits (duration of oviposition and of pre- and post-oviposition periods, and lifetime oviposition), and offspring quality (egg size and offspring survival) of the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae), an important biological control agent against spider mites.
View Article and Find Full Text PDFCouple-Based Intervention to Improve HIV Care Engagement for Women and their Partners in KwaZulu-Natal, South Africa: Outcomes of a Pilot Randomized Controlled Trial.
J Int Assoc Provid AIDS Care
January 2025
Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.
We evaluated a couple-based intervention targeting human immunodeficiency virus (HIV) care needs of women, with the option to support HIV-related needs of male partners. Adult women with HIV adherence difficulties in a monogamous relationship with a male partner for ≥6 months were recruited in KwaZulu-Natal, South Africa. Twenty couples were randomized (1:1) to either START Together, a five-session manualized behavioral intervention, or treatment as usual, adherence counseling referral.
View Article and Find Full Text PDFUnderstanding the reproductive ecology of Macrognathus aculeatus in wetland (Gajner beel) ecosystem: insights into eco-climatic influences in northwestern Bangladesh.
Environ Sci Pollut Res Int
January 2025
Department of Fisheries, University of Rajshahi, Rajshahi, 6205, Bangladesh.
The lesser spiny eel, Macrognathus aculeatus (Bloch, 1786), holds substantial economic importance as a food fish in South Asia, due to its exceptional nutritional value. This study was conducted to investigate the reproductive ecology of M. aculeatus within the Gajner beel wetland ecosystem in northwestern Bangladesh, with a specific focus on size at sexual maturity, spawning season, and fecundity in relation to eco-climatic variables.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!