Sexual selection impacts brain anatomy in frogs
and toads

Zeng, Y; Luo, S; Liao, WB; Jehle, R; Kotrschal, A

Abstract

Natural selection is a major force in the evolution of vertebrate brain size, but the role
of sexual selection in brain size evolution remains enigmatic. At least two opposing
schools of thought predict a relationship between sexual selection and brain size.
Sexual selection should facilitate the evolution of larger brains because better cognitive
abilities may aid the competition for mates. However, it may also restrict brain size
evolution due to energetic trade-offs
between brain tissue and sexually selected traits.
Here, we examined the patterns of selection on brain size and brain anatomy in male
anurans (frogs and toads), a group where the strength of sexual selection differs markedly
among species, using a phylogenetically controlled generalized least-squared
(PGLS) regression analyses. The analysis revealed that in 43 Chinese anuran species,
neither mating system, nor type of courtship, or testes mass was significantly associated
with relative brain size. While none of those factors related to the relative size of
olfactory nerves, optic tecta, telencephalon, and cerebellum, the olfactory bulbs were
relatively larger in monogamous species and those using calls during courtship. Our
findings support the mosaic model of brain evolution and suggest that while the investigated
aspects of sexual selection do not seem to play a prominent role in the evolution
of brain size of anurans, they do impact their brain anatomy.

Citation

and toads. Ecology and Evolution, 6(19), 7070-7079. https://doi.org/10.1002/ece3.2459

• Journal Article Type: Article
• Acceptance Date: Aug 18, 2016
• Online Publication Date: Sep 12, 2016
• Publication Date: Oct 4, 2016
• Deposit Date: Sep 14, 2016
• Publicly Available Date: Sep 14, 2016
• Journal: Ecology and Evolution
• Publisher: Wiley
• Volume: 6
• Issue: 19
• Pages: 7070-7079
• DOI: https://doi.org/10.1002/ece3.2459
• Publisher URL: http://dx.doi.org/10.1002/ece3.2459
• Related Public URLs: http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)2045-7758
• Additional Information: Funders : National Natural Sciences Foundation of China;Austrian Science Fund;Sichuan Province Outstanding Youth Academic Technology Leaders Program;Sichuan Province Department of Education Innovation Team Project; Grant Number: 31471996; Grant Number: 3304‐B24; Grant Number: 2013JQ0016; Grant Number: 14TD0015, 15TD0019