Sexual Dimorphism, Mating System and Body Size in New World Blackbirds (Icterinae)

Evolution ◽  
1992 ◽  
Vol 46 (6) ◽  
pp. 1621 ◽  
Author(s):  
Michael S. Webster
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Mating System ◽  
New World

Host-use pattern and sexual dimorphism reveals the mating system of the symbiotic pea crabAustinixa aidae(Crustacea: Brachyura: Pinnotheridae)

2012 ◽  
Vol 93 (3) ◽  
pp. 715-723 ◽  
Author(s):  
Douglas F. Peiró ◽  
J. Antonio Baeza ◽  
Fernando L. Mantelatto
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Mating System ◽  
Reproductive Strategies ◽  
The Body ◽  
Host Use ◽  
Decapod Crustaceans ◽  
Body Coloration ◽  
Early Embryos ◽  
Use Pattern

Austinixa aidaeinhabits burrows of the ghost shrimpCallichirus majorat Perequê-açu beach, Ubatuba, Brazil. We described the host-use pattern and sexual dimorphism ofA. aidaeto test for monogamy given the generality of this mating system in the subfamily Pinnothereliinae (family Pinnotheridae) to whichA. aidaebelongs. Against expectations,A. aidaelives as solitary individuals within burrows more frequently than expected by chance alone. Additional observations suggested thatA. aidaeexhibits a polygynandrous mating system with males moving among burrows in search of receptive females. First, only 21% of the burrows harboured heterosexual pairs of crabs and the body size of paired crabs was poorly correlated. This suggests pair instability and frequent shifts among burrows by male and/or female crabs, as reported before for other symbiotic crustaceans in which the body size of paired crabs is poorly correlated. Second, males paired with females that were sexually receptive (without embryos) or that have been receptive recently (carrying early embryos) were found more frequently than expected by chance alone. The above agrees with that reported for species in which sexual pairing does not last long. Third, sexual dimorphism in terms of claw size and coloration was evident. Claws were larger in males than in females, a condition that argues in favour of male–male competition inA. aidae. In addition, the body coloration of males was more similar to the sand grains of the beach than that of females. This sex-specific coloration suggests that males are ‘better adapted' than females to roam on the surface of the beach in search of burrows because their coloration should diminish the risk of detection by predators. Experiments are needed to reveal the details of the polygynandrous mating system herein inferred forA. aidaeand to understand those conditions favouring particular reproductive strategies in symbiotic decapod crustaceans.

Brontostoma lilloi Carpintero, 1980, a junior synonym of B. rubrovenosum (Stål, 1860) (Hemiptera: Heteroptera: Reduviidae)

Zootaxa ◽  
2019 ◽  
Vol 4614 (1) ◽  
pp. 180
Author(s):  
HÉLCIO R. GIL-SANTANA ◽  
DIEGO L. CARPINTERO
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Geographic Variation ◽  
Intraspecific Variation ◽  
New World ◽  
Junior Synonym

There are 22 genera and more than 100 described species of Ectrichodiinae in the New World (Gil-Santana et al. 2015). Intraspecific variation in coloration and body size have been recorded in several species of the subfamily. These characteristics can occur in the same population or can suggest geographic variation of the same species (Wygodzinsky 1951, Dougherty 1995, Gil-Santana & Baena 2009, Gil-Santana et al. 2013). Sexual dimorphism is also common: females are almost always more or less larger than males, frequently have thicker fore femora and smaller eyes and ocelli (Dougherty 1995). 

scholarly journals Sexual conflict drives micro- and macroevolution of sexual dimorphism in immunity

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Basabi Bagchi ◽  
Quentin Corbel ◽  
Imroze Khan ◽  
Ellen Payne ◽  
Devshuvam Banerji ◽  
...  
Keyword(s):  
Sex Differences ◽  
Sexual Dimorphism ◽  
Mating System ◽  
Sexual Conflict ◽  
Experimental Evolution ◽  
Parasitic Infections ◽  
Pathogen Dynamics ◽  
Trade Offs ◽  
Host Pathogen ◽  
Seed Beetles

Abstract Background Sexual dimorphism in immunity is believed to reflect sex differences in reproductive strategies and trade-offs between competing life history demands. Sexual selection can have major effects on mating rates and sex-specific costs of mating and may thereby influence sex differences in immunity as well as associated host–pathogen dynamics. Yet, experimental evidence linking the mating system to evolved sexual dimorphism in immunity are scarce and the direct effects of mating rate on immunity are not well established. Here, we use transcriptomic analyses, experimental evolution and phylogenetic comparative methods to study the association between the mating system and sexual dimorphism in immunity in seed beetles, where mating causes internal injuries in females. Results We demonstrate that female phenoloxidase (PO) activity, involved in wound healing and defence against parasitic infections, is elevated relative to males. This difference is accompanied by concomitant sex differences in the expression of genes in the prophenoloxidase activating cascade. We document substantial phenotypic plasticity in female PO activity in response to mating and show that experimental evolution under enforced monogamy (resulting in low remating rates and reduced sexual conflict relative to natural polygamy) rapidly decreases female (but not male) PO activity. Moreover, monogamous females had evolved increased tolerance to bacterial infection unrelated to mating, implying that female responses to costly mating may trade off with other aspects of immune defence, an hypothesis which broadly accords with the documented sex differences in gene expression. Finally, female (but not male) PO activity shows correlated evolution with the perceived harmfulness of male genitalia across 12 species of seed beetles, suggesting that sexual conflict has a significant influence on sexual dimorphisms in immunity in this group of insects. Conclusions Our study provides insights into the links between sexual conflict and sexual dimorphism in immunity and suggests that selection pressures moulded by mating interactions can lead to a sex-specific mosaic of immune responses with important implications for host–pathogen dynamics in sexually reproducing organisms.

Sexual dimorphism in human cranial trait scores: Effects of population, age, and body size

2014 ◽  
Vol 154 (2) ◽  
pp. 259-269 ◽  
Author(s):  
Heather M. Garvin ◽  
Sabrina B. Sholts ◽  
Laurel A. Mosca
Keyword(s):  
Body Size ◽  
Sexual Dimorphism

Body size, brain size, and sexual dimorphism in Homo naledi from the Dinaledi Chamber

2017 ◽  
Vol 111 ◽  
pp. 119-138 ◽  
Author(s):  
Heather M. Garvin ◽  
Marina C. Elliott ◽  
Lucas K. Delezene ◽  
John Hawks ◽  
Steven E. Churchill ◽  
...  
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Brain Size

scholarly journals Exquisitely Preserved Fossil Snakes of Messel: Insight into the Evolution, Biogeography, Habitat Preferences and Sensory Ecology of Early Boas

Diversity ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 100 ◽  
Author(s):  
Agustín Scanferla ◽  
Krister T. Smith
Keyword(s):  
Body Size ◽  
New World ◽  
Middle Eocene ◽  
Habitat Preferences ◽  
Sensory Ecology ◽  
Morphological Diversity ◽  
Predator Prey ◽  
Upper Jaw ◽  
Spectrum Evaluation ◽  
Insight Into

Our knowledge of early evolution of snakes is improving, but all that we can infer about the evolution of modern clades of snakes such as boas (Booidea) is still based on isolated bones. Here, we resolve the phylogenetic relationships of Eoconstrictor fischeri comb. nov. and other booids from the early-middle Eocene of Messel (Germany), the best-known fossil snake assemblage yet discovered. Our combined analyses demonstrate an affinity of Eoconstrictor with Neotropical boas, thus entailing a South America-to-Europe dispersal event. Other booid species from Messel are related to different New World clades, reinforcing the cosmopolitan nature of the Messel booid fauna. Our analyses indicate that Eoconstrictor was a terrestrial, medium- to large-bodied snake that bore labial pit organs in the upper jaw, the earliest evidence that the visual system in snakes incorporated the infrared spectrum. Evaluation of the known palaeobiology of Eoconstrictor provides no evidence that pit organs played a role in the predator–prey relations of this stem boid. At the same time, the morphological diversity of Messel booids reflects the occupation of several terrestrial macrohabitats, and even in the earliest booid community the relation between pit organs and body size is similar to that seen in booids today.

Sign in / Sign up

Export Citation Format

Share Document