Predation pressure shapes brain anatomy in the wild

Area of Science:

• Neuroscience
• Evolutionary Biology
• Ecology

Background:

• Vertebrate brain anatomy exhibits significant diversity.
• Predatory interactions are increasingly recognized as a key driver of this anatomical diversity.

Purpose of the Study:

• To investigate the relationship between predation pressure and brain anatomy in wild guppy populations.
• To determine how different predator types (prawns, fish) influence specific brain structures and overall brain size.

Main Methods:

• Collected female guppies from 16 wild populations.
• Assessed brain anatomy in relation to local predation factors: predator biomass and predator diversity.
• Analyzed correlations between environmental predation data and brain measurements.

Main Results:

• Higher prawn biomass was linked to larger telencephalon size and overall brain size.
• Optic tectum size positively correlated with fish predator biomass and predator diversity.
• Olfactory bulb and hypothalamus size showed negative associations with a specific fish predator's biomass.

Conclusions:

• Predator communities significantly influence prey brain anatomy in natural environments.
• Different predators exert distinct selective pressures, leading to varied brain adaptations in guppies.
• Cognitive demands imposed by predation likely drive observed changes in brain morphology.