Genomic and phenotypic evidence support visual and olfactory shifts in primate evolution

Area of Science:

• Evolutionary biology
• Sensory ecology
• Primate genomics

Background:

• Primate sensory evolution, particularly vision-olfaction trade-offs, remains debated due to limited genetic and functional data.
• Understanding sensory adaptations requires analyzing visual and olfactory receptors alongside brain region evolution.

Purpose of the Study:

• To investigate sensory trade-offs and reallocation in primate evolution using large-scale functional analyses.
• To characterize evolutionary shifts in visual and olfactory receptor sensitivity and their correlation with neuroanatomy.

Main Methods:

• Functional analyses of visual and olfactory receptors across extant primates.
• Comparative genomic and molecular analyses of sensory genes.
• Modeling of visual acuity and olfactory receptor tuning.

Main Results:

• Early haplorrhines shifted visual sensitivity from ultraviolet to violet, enhancing acuity in bright light.
• Anthropoids accelerated rhodopsin retinal release rates, further improving vision under bright conditions.
• Olfactory receptors shifted from narrow to broad tuning in anthropoids; strepsirrhines retained dim-light vision and enhanced narrowly tuned olfactory receptors.

Conclusions:

• Primate sensory evolution involved a reallocation of resources, not strict vision-olfaction trade-offs.
• Distinct evolutionary paths in vision and olfaction correlate with primate lineage morphology and brain structures.
• Genomic, molecular, and neuroanatomical data reveal mechanisms of olfactory adaptation and evolutionary plasticity.