A smaller habenula is associated with increasing intensity of sexual selection

Daniel Hoops*, Martin J. Whiting, J. Scott Keogh

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    3 Citations (Scopus)
    10 Downloads (Pure)


    The habenula is a small structure in the brain that acts as a relay station for neural information, helping to modulate behaviour in response to variable and unpredictable stimuli. Broadly, it is evolutionarily conserved in structure and connectivity across vertebrates and is the most prominent bilaterally asymmetric structure in the brain. Nonetheless, comparative evolutionary studies of the habenula are virtually non-existent. Here, we examine the volumes of the medial and lateral habenular subregions, in both hemispheres, across a group of Australian agamid lizards in the genus Ctenophorus. In males, we found bilaterally asymmetrical selection on the lateral habenula to become smaller with increasing intensity of sexual selection, possibly as a mechanism to increase aggressive responses. In females, we found bilaterally symmetrical selection on both the medial and lateral subregions to become smaller with increasing sexual selection. This is consistent with sexual selection increasing motivation to reproduce and the habenula's well-characterized role in controlling and modifying responses to rewarding stimuli. However, as there are currently no studies addressing habenular function in reptiles, it is difficult to draw more precise conclusions. As has happened recently in biomedical neuroscience, it is time for the habenula to receive greater attention in evolutionary neuroscience.

    Original languageEnglish
    Pages (from-to)265-273
    Number of pages9
    JournalBrain, Behavior and Evolution
    Issue number5
    Early online date4 Jan 2022
    Publication statusPublished - Aug 2022

    Bibliographical note

    Copyright the Author(s) 2022. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.


    • Brain evolution
    • Comparative neuroanatomy
    • Lateralization
    • Reproductive behaviour
    • Reptiles


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