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Sexual selection impacts brain anatomy in frogs and toads
Yu Zeng1, Shang Ling Lou1, Wen Bo Liao1
1Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education) China West Normal University Nanchong Sichuan China.
Ecology and Evolution
|July 21, 2017
Summary
Sexual selection does not significantly impact anuran brain size, but influences specific brain anatomy like olfactory bulbs. This research explores sexual selection
Area of Science:
- Evolutionary biology
- Neuroscience
- Zoology
Background:
- Natural selection influences vertebrate brain size.
- The role of sexual selection in brain evolution is unclear.
- Sexual selection may increase or decrease brain size due to cognitive demands or energetic trade-offs.
Purpose of the Study:
- Investigate the relationship between sexual selection and brain size in male anurans (frogs and toads).
- Examine how mating systems and courtship behaviors affect brain anatomy.
- Test hypotheses regarding sexual selection's impact on brain evolution.
Main Methods:
- Phylogenetically controlled generalized least-squared (PGLS) regression analyses were used.
- Data were collected from 43 Chinese anuran species.
- Relative brain size and the size of specific brain regions (olfactory nerves, optic tecta, telencephalon, cerebellum, olfactory bulbs) were measured.
Main Results:
- No significant association was found between mating system, courtship type, or testes mass and relative brain size.
- None of the investigated sexual selection factors related to the relative size of olfactory nerves, optic tecta, telencephalon, or cerebellum.
- Olfactory bulbs were relatively larger in monogamous anurans and those using calls during courtship.
Conclusions:
- The study supports the mosaic model of brain evolution.
- Investigated aspects of sexual selection do not appear to be a major driver of overall anuran brain size evolution.
- Sexual selection does influence specific brain anatomy, such as olfactory bulb size, in anurans.
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