Group-level phenotypes are idiosyncratic yet unpredictable over development in a clonal fish
6 affiliations
- 1Department of Evolution and Ecology, University of California Davis, Davis, California, 95616 USA
- 2Department of Ecology and Complexity, Centre for Advanced Studies Blanes (CSIC-CEAB), 17300 Blanes, Girona, Spain
- 3Department of Biology and Ecology of Fishes, Leibniz Institute of Freshwater Ecology and Inland Fisheries, 12587 Berlin-Bezirk Treptow-Köpenick, Germany
- 4European Citizen Science Association, 10115 Berlin, Germany
- 5SCIoI Excellence Cluster, Technische Universität Berlin, 10587 Berlin, Germany
- 6Faculty of Life Sciences, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Humboldt-Universität zu Berlin, Invalidenstrasse 42, 10115, Berlin, Germany
Abstract
Behavioral differences among groups can have profound impacts on individual fitness, 1 yet how group-level phenotypes arise and change during development is poorly understood. Group-level differences may originate from genetic differences or subtle variation among individuals, 2 , 3 , 4 , 5 but they can also emerge over time through social feedback mechanisms within and between groups, potentially producing dramatically different group-level behavior. 6 , 7 , 8 Disentangling these drivers of group phenotypes is challenging because groups are typically studied after they are already well established. Using the naturally clonal Amazon molly, we establish replicate groups of genetically identical individuals and continuously track group-level behavior from birth throughout the first 55 days of life. This design allows us to control for genetic and environmental sources of variance, thereby establishing a null baseline for group-level differences. Furthermore, by recording over an extended period beginning from day 1 of life, we test whether group phenotypes follow predictable trajectories driven by individual differences or instead diverge due to social feedback during development. We find that average behavioral changes across groups follow predictable patterns during this early developmental phase. In contrast, differences among groups are highly unstable over longer timescales: although groups differ from very early in life, it appears that the rank-order of group-level phenotypes undergoes a shuffling mid-development, around 4–5 weeks of age. These results suggest that distinct processes generate group-level variation across ontogeny, with early differences largely reflecting consistent individual variation; then as individuals mature and become more socially responsive, social feedback pushes groups along divergent, less predictable behavioral trajectories.
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BibTeX
@article{perkes2026grouplevel,
title = {{Group-level phenotypes are idiosyncratic yet unpredictable over development in a clonal fish}},
author = {Ammon Perkes and Jolle Jolles and Carolina Doran and David Bierbach and Max Wolf and Kate L Laskowski},
journal = {Current biology : CB},
year = {2026},
month = sep,
doi = {10.1016/j.cub.2026.08.073},
url = {https://doi.org/10.1016/j.cub.2026.08.073},
note = {CC BY-NC},
}
RIS
TY - JOUR
TI - Group-level phenotypes are idiosyncratic yet unpredictable over development in a clonal fish
AU - Ammon Perkes
AU - Jolle Jolles
AU - Carolina Doran
AU - David Bierbach
AU - Max Wolf
AU - Kate L Laskowski
PY - 2026
DA - 2026/09/18
JO - Current biology : CB
DO - 10.1016/j.cub.2026.08.073
UR - https://doi.org/10.1016/j.cub.2026.08.073
AB - Behavioral differences among groups can have profound impacts on individual fitness, 1 yet how group-level phenotypes arise and change during development is poorly understood. Group-level differences may originate from genetic differences or subtle variation among individuals, 2 , 3 , 4 , 5 but they can also emerge over time through social feedback mechanisms within and between groups, potentially producing dramatically different group-level behavior. 6 , 7 , 8 Disentangling these drivers of group phenotypes is challenging because groups are typically studied after they are already well established. Using the naturally clonal Amazon molly, we establish replicate groups of genetically identical individuals and continuously track group-level behavior from birth throughout the first 55 days of life. This design allows us to control for genetic and environmental sources of variance, thereby establishing a null baseline for group-level differences. Furthermore, by recording over an extended period beginning from day 1 of life, we test whether group phenotypes follow predictable trajectories driven by individual differences or instead diverge due to social feedback during development. We find that average behavioral changes across groups follow predictable patterns during this early developmental phase. In contrast, differences among groups are highly unstable over longer timescales: although groups differ from very early in life, it appears that the rank-order of group-level phenotypes undergoes a shuffling mid-development, around 4–5 weeks of age. These results suggest that distinct processes generate group-level variation across ontogeny, with early differences largely reflecting consistent individual variation; then as individuals mature and become more socially responsive, social feedback pushes groups along divergent, less predictable behavioral trajectories.
SN - 0960-9822
SN - 1879-0445
ER -