Mammals with significant differences in sex sizes have larger gene families for smell-related functions and smaller ones for brain development, according to a new study. Conversely, species with minimal size differences between genders invest more in brain development and complex social behaviors. The findings suggest that sexual size dimorphism (SSD) impacts the evolution of sensory and cognitive traits in mammals.
The research team from the University of Bath examined gene families in 124 mammal species, discovering that those with larger SSD had bigger olfactory gene families and smaller brain development ones. Conversely, monomorphic species (those with minimal size differences) had larger brain development gene families.
This study implies that in large SSD species, traits like smell could play a significant role in identifying mates and territories. In contrast, mammals with a small SSD focus on brain development and exhibit more complex social structures.
The researchers were surprised to find such a strong correlation between gene family size and SSD. They plan to investigate the impact of testes size on mammal genome evolution in future work. The study is published in Nature Communications.
Source: https://neurosciencenews.com/genetics-brain-evolution-26784/