Coexisting With Humans: Genomic and Behavioral Consequences in a Small and Isolated Bear Population

Area of Science:

• Evolutionary genetics
• Conservation biology
• Wildlife ecology

Background:

• Climate and land use changes increase human-wildlife interactions.
• Behavioral adaptations in wildlife are debated as phenotypic plasticity or driven by human selection.
• Small, isolated populations face strong genetic drift, complicating adaptation studies.

Purpose of the Study:

• To investigate genomic diversity and adaptation signals in the Apennine brown bear population (Ursus arctos marsicanus).
• To determine if behavioral changes in this population are due to phenotypic plasticity or human-induced selection.
• To compare genomic data with Central European and North American brown bear populations.

Main Methods:

• Whole-genome resequencing data analysis.
• Comparison of genomic diversity between Apennine, Central European, and North American brown bears.
• Identification of selective signatures and genetic variants, including noncoding variations.

Main Results:

• Apennine brown bears exhibit reduced genomic diversity, higher inbreeding, and increased genetic load compared to other populations.
• Unique genomic patterns and selective signatures were identified, particularly in genes associated with reduced aggressiveness (e.g., DCC, SLC13A5).
• Noncoding variants, including those affecting splicing factor binding sites, contribute to phenotypic adaptations.

Conclusions:

• Human-induced selection has promoted behavioral changes, such as reduced aggressiveness, in the small, isolated Apennine brown bear population.
• These adaptations facilitate coexistence with humans and contribute to the species' long-term persistence.
• Noncoding genetic variations play a significant role in shaping complex phenotypes and adaptive evolution.