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Research article - Peer-reviewed, 2021

Rapid mosaic brain evolution under artificial selection for relative telencephalon size in the guppy (Poecilia reticulata)

Fong, Stephanie; Rogell, Bjorn; Amcoff, Mirjam; Kotrschal, Alexander; van der Bijl, Wouter; Buechel, Severine D.; Kolm, Niclas;


The mosaic brain evolution hypothesis, stating that brain regions can evolve relatively independently during cognitive evolution, is an important idea to understand how brains evolve with potential implications even for human brain evolution. Here, we provide the first experimental evidence for this hypothesis through an artificial selection experiment in the guppy (Poecilia reticulata). After four generations of selection on relative telencephalon volume (relative to brain size), we found substantial changes in telencephalon size but no changes in other regions. Further comparisons revealed that up-selected lines had larger telencephalon, while down-selected lines had smaller telencephalon than wild Trinidadian populations. Our results support that independent evolutionary changes in specific brain regions through mosaic brain evolution can be important facilitators of cognitive evolution.

Published in

Science Advances

2021, volume: 7, number: 46, article number: eabj4314

Authors' information

Fong, Stephanie
Stockholm University
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Stockholm University
Amcoff, Mirjam
Stockholm University
Kotrschal, Alexander
Stockholm University
van der Bijl, Wouter
University of British Columbia
Buechel, Severine D.
Stockholm University
Kolm, Niclas
Stockholm University

UKÄ Subject classification

Evolutionary Biology

Publication Identifiers


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