How domestication, feralization and experience-dependent plasticity affect brain size variation in Sus scrofa

Area of Science:

• Zoology
• Evolutionary Biology
• Neuroscience

Background:

• Domestication leads to significant physiological changes in animals.
• Pigs (Sus scrofa) exhibit notable brain size reduction, but the extent and causes are debated.

Purpose of the Study:

• To investigate the effects of domestication, feralization, and captivity on brain size variation in Sus scrofa.
• To quantify brain size reduction in domestic pigs compared to wild boars.

Main Methods:

• Analysis of brain endocast volume from 92 adult Sus scrofa skulls.
• Comparison of brain size across wild, captive, feral, and domestic populations.

Main Results:

• Observed an 18% brain size reduction in domestic pigs versus wild boars, differing from prior studies.
• No significant sexual dimorphism in brain volume was detected.
• Feral pigs in Australia showed brain size reduction, likely an adaptation to environmental scarcity.
• Captive-reared wild boars exhibited a slight brain size increase.

Conclusions:

• Domestication significantly impacts pig brain size, with an 18% reduction observed.
• Environmental factors like diet and scarcity play a crucial role in brain evolution during domestication.
• Further research is needed on the influence of environment and experience on brain size during animal domestication.