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Decoding Natural Behavior from Neuroethological Embedding
Published on: October 3, 2025
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Serotonin, behavior, and natural selection in New World monkeys
Guillermo Reales1, Vanessa R Paixão-Côrtes2, Gabriela B Cybis3
1Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Journal of Evolutionary Biology
|June 27, 2018
Summary
Natural selection shaped the serotonin receptor HTR3A in primates, influencing social behaviors like dispersal and monogamy in New World monkeys. These genetic changes may enhance survival and fitness.
Area of Science:
- Evolutionary biology
- Neuroscience
- Primate genetics
Background:
- Social behavior is critical for animal survival and often shaped by natural selection.
- Neurotransmitter systems, including serotonin (5-HT), are key genetic networks regulating behavior.
Purpose of the Study:
- To identify positive selection signals within the serotonin (5-HT) system in primates.
- To investigate the association between selected genetic variants in the serotonin 3A receptor (HTR3A) and social behaviors.
Main Methods:
- Molecular analyses were used to detect positive selection signals in the HTR3A gene.
- Statistical and Bayesian methods were employed to associate amino acid variants with social traits.
Main Results:
- Positive selection signals were found in the HTR3A gene, particularly in New World monkeys (NWM).
- Specific amino acid variants (e.g., 398L, 403G, 416S) were significantly associated with unbiased sex dispersal, dominance, and social monogamy.
- A GSK3 ligand motif, potentially influencing neurodevelopment and behavior, was identified in a selected variant unique to NWM.
Conclusions:
- Genetic variations in the HTR3A receptor, driven by positive selection, are linked to adaptive social behaviors in NWM.
- These findings suggest a role for the serotonin system in the evolution of primate sociality and fitness.
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