scholarly journals It is not always about body size: evidence of Rensch's rule in a male weapon

2021 ◽  
Vol 17 (6) ◽  
pp. 20210234
Author(s):  
Glauco Machado ◽  
Bruno A. Buzatto ◽  
Diogo S. M. Samia
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Potential Role ◽  
Empirical Studies ◽  
Condition Dependence ◽  
Rensch’S Rule ◽  
Evolutionary Pattern ◽  
Rensch's Rule ◽  
Original Proposal

In many species, sexual dimorphism increases with body size when males are the larger sex but decreases when females are the larger sex, a macro-evolutionary pattern known as Rensch's rule (RR). Although empirical studies usually focus exclusively on body size, Rensch's original proposal included sexual differences in other traits, such as ornaments and weapons. Here, we used a clade of harvestmen to investigate whether two traits follow RR: body size and length of the fourth pair of legs (legs IV), which are used as weapons in male–male fights. We found that males were slightly smaller than females and body size did not follow RR, whereas legs IV were much longer in males and followed RR. We propose that sexual selection might be stronger on legs IV length than on body size in males, and we discuss the potential role of condition dependence in the emergence of RR.

scholarly journals Evolution of sexual dimorphism and Rensch’s rule in the beetle genusLimnebius(Hydraenidae): is sexual selection opportunistic?

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3060 ◽  
Author(s):  
Andrey Rudoy ◽  
Ignacio Ribera
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
General Pattern ◽  
Strong Support ◽  
Male Body ◽  
Rensch’S Rule ◽  
Male Body Size ◽  
Rensch's Rule ◽  
The Individual ◽  
Male Genital

Sexual size dimorphism (SSD) is widespread among animals, with larger females usually attributed to an optimization of resources in reproduction and larger males to sexual selection. A general pattern in the evolution of SSD is Rensch’s rule, which states that SSD increases with body size in species with larger males but decreases when females are larger. We studied the evolution of SSD in the genusLimnebius(Coleoptera, Hydraenidae), measuring SSD and male genital size and complexity of ca. 80% of its 150 species and reconstructing its evolution in a molecular phylogeny with 71 species. We found strong support for a higher evolutionary lability of male body size, which had an overall positive allometry with respect to females and higher evolutionary rates measured over the individual branches of the phylogeny. Increases in SSD were associated to increases in body size, but there were some exceptions with an increase associated to changes in only one sex. Secondary sexual characters (SSC) in the external morphology of males appeared several times independently, generally on species that had already increased their size. There was an overall significant correlation between SSD, male body size and male genital size and complexity, although some lineages with complex genitalia had low SSD, and some small species with complex genitalia had no SSD. Our results suggest that the origin of the higher evolutionary variance of male body size may be due to lack of constraints rather than to sexual selection, that may start to act in species with already larger males due to random variation.

Season of birth and subsequent body size: The potential role of prenatal vitamin D

2010 ◽  
Vol 23 (2) ◽  
pp. 190-200 ◽  
Author(s):  
Marta Krenz-Niedbała ◽  
Elżbieta A. Puch ◽  
Krzysztof Kościński
Keyword(s):  
Vitamin D ◽  
Body Size ◽  
Potential Role ◽  
Season Of Birth

scholarly journals Sexual selection explains Rensch's rule of size dimorphism in shorebirds

2004 ◽  
Vol 101 (33) ◽  
pp. 12224-12227 ◽  
Author(s):  
T. Szekely ◽  
R. P. Freckleton ◽  
J. D. Reynolds
Keyword(s):  
Sexual Selection ◽  
Rensch’S Rule ◽  
Size Dimorphism ◽  
Rensch's Rule

scholarly journals Bigger Males, Bigger Females? Pigeons’ Sexual Size Dimorphism

2020 ◽  
pp. 20-24
Author(s):  
P. M. Parés- Casanova ◽  
A. Kabir
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Sexual Size Dimorphism ◽  
Wing Length ◽  
Rensch’S Rule ◽  
Size Dimorphism ◽  
Rensch's Rule ◽  
Neck Thickness ◽  
Males And Females ◽  
Domestic Pigeons

Sexual dimorphism, defined as phenotypic differences between males and females, is a common phenomenon in animals. In this line, Rensch’s rule states that sexual size dimorphism increases with increasing body size when the male is the larger sex and decreases with increasing average body size when the female is the larger sex. Domesticated animals offer excellent opportunities for testing predictions of functional explanations of Rensch’s theory. Pigeon breeds encounters many different functional purposes and selective constraints, which could influence strongly their morphology. The aim of this paper is to examine, for first time, Rensch’s rule among domestic pigeons. It was compiled a database of 12 quantitative traits (body weight, body height, beak thickness, beak length, neck length, neck thickness, wing length, rump width, tail length, tarsus length, tarsus thickness and middle toe length) for males and females of 11 different domestic pigeon breeds: Bangladesh Indigenous, Racing Homer, Turkish Tumbler, Indian Lotan, Kokah, Mookee, Indian Fantail, Bokhara Trumpeter, Bombai, Lahore and Hungarian Giant House; Rock Pigeon (Columba livia) was also considered as wild relative for comparative purposes. Comparative results between males and females showed that only body weight, wing length and neck thickness were consistent with Rensch’s rule. The rest of trait did not present correlations. Among domestic pigeons, there can appear different expressions of dimorphism according to each trait, so it must be considered that Rensch’s rule vary when considering other traits than body weight.

scholarly journals Sexual selection explains Rensch's rule of allometry for sexual size dimorphism

2007 ◽  
Vol 274 (1628) ◽  
pp. 2971-2979 ◽  
Author(s):  
James Dale ◽  
Peter O Dunn ◽  
Jordi Figuerola ◽  
Terje Lislevand ◽  
Tamás Székely ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Sexual Size Dimorphism ◽  
Bird Species ◽  
Confounding Factors ◽  
Allometric Relationship ◽  
Rensch’S Rule ◽  
Size Dimorphism ◽  
Rensch's Rule ◽  
Clear Solution ◽  
General Explanation

In 1950, Rensch first described that in groups of related species, sexual size dimorphism is more pronounced in larger species. This widespread and fundamental allometric relationship is now commonly referred to as ‘Rensch's rule’. However, despite numerous recent studies, we still do not have a general explanation for this allometry. Here we report that patterns of allometry in over 5300 bird species demonstrate that Rensch's rule is driven by a correlated evolutionary change in females to directional sexual selection on males. First, in detailed multivariate analysis, the strength of sexual selection was, by far, the strongest predictor of allometry. This was found to be the case even after controlling for numerous potential confounding factors, such as overall size, degree of ornamentation, phylogenetic history and the range and degree of size dimorphism. Second, in groups where sexual selection is stronger in females, allometry consistently goes in the opposite direction to Rensch's rule. Taken together, these results provide the first clear solution to the long-standing evolutionary problem of allometry for sexual size dimorphism: sexual selection causes size dimorphism to correlate with species size.

Evolution of sexual dimorphism in the plateau brown frog fails to obey Rensch’s rule

2022 ◽  
pp. 27-33
Author(s):  
Tong Lei Yu
Keyword(s):  
Body Size ◽  
Large Male ◽  
Large Female ◽  
Female Size ◽  
Rensch’S Rule ◽  
Size Dimorphism ◽  
Rensch's Rule ◽  
Males And Females ◽  
Brown Frog ◽  
Using Data

Rensch’s rule describes sexual size dimorphism (SSD) that decreases with increasing body size when females are larger than males and SSD that increases when males are larger than females. The plateau brown frog Rana kukunoris, a species endemic to the eastern Tibetan Plateau, exhibits female-biased size dimorphism. Using data on body size from 26 populations and age from 21 populations, we demonstrated that SSD did not increase with increasing mean female snout-vent length (SVL) when controlling for sex-specific age structure, failing to support the Rensch’s rule. Thus, we suggest that fecundity selection (favouring large female size) balances out sexual selection (favouring large male size), which results in a similar divergence between males and females body size. In addition, sex-specific age differences explained most of the variation of SSD across populations.

Male terminalia morphology of sixteen species of the Drosophila saltans group Sturtevant (Diptera, Drosophilidae)

Zootaxa ◽  
2021 ◽  
Vol 5061 (3) ◽  
pp. 523-544
Author(s):  
BRUNA EMILIA ROMAN ◽  
LILIAN MADI-RAVAZZI
Keyword(s):  
Sexual Selection ◽  
Sibling Species ◽  
Potential Role ◽  
Rapid Evolution ◽  
Variable Structure ◽  
Diagnostic Feature ◽  
Internal Fertilization ◽  
Saltans Group

Male terminalia in insects with internal fertilization evolve more rapidly than other structures. The aedeagus is the most variable structure, making it a valuable diagnostic feature to distinguish species. The saltans group Sturtevant of Drosophila Fallén contains sibling species, that can be distinguished by their aedeagi. Here, we revised and illustrated the morphology of the male terminalia of the following species: Drosophila prosaltans Duda, 1927; D. saltans Sturtevant, 1916; D. lusaltans Magalhães, 1962; D. austrosaltans Spassky, 1957; D. septentriosaltans Magalhães, 1962; D. nigrosaltans Magalhães, 1962; D. pseudosaltans Magalhães, 1956; D. sturtevanti Duda, 1927; D. lehrmanae Madi-Ravazzi et al., 2021; D. dacunhai Mourão & Bicudo, 1967; D. milleri Magalhães, 1962; D. parasaltans Magalhães, 1956; D. emarginata Sturtevant, 1942; D. neoelliptica Pavan & Magalhães in Pavan, 1950; D. neosaltans Pavan & Magalhães in Pavan, 1950 and D. neocordata Magalhães, 1956. We found that phallic structures (e.g., the aedeagus) evolve more rapidly than periphallic structures (e.g., epandrium), being completely different among the subgroups and within them. This rapid evolution may be due to the action of sexual selection or to the potential role of those structures in speciation.  

Sign in / Sign up

Export Citation Format

Share Document