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

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 i...

Full description

Saved in:
Bibliographic Details
Published in:Biology letters (2005) 2021-06, Vol.17 (6), p.20210234-20210234
Main Authors: Machado, Glauco, Buzatto, Bruno A, Samia, Diogo S M
Format: Article
Language:English
Subjects:
Biological Evolution
Body Size
Evolutionary Biology
Female
Humans
Male
Phenotype
Sex Characteristics
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:1744-957X
1744-9561
1744-957X
DOI:10.1098/rsbl.2021.0234