While bear attacks appear to have become a significant problem in Japan – with the country going so far as to deploy the military – new research reveals that an Italian bear species has evolved to be less aggressive.
Apennine brown bears (Martian bear) have been in close contact with humans for generations. Their small, endangered population exists only in central Italy, and previous research suggests that this population split from other European brown bears 2,000 to 3,000 years ago. As a result, they have been completely isolated from other bears since the times of the Roman Empire. Compared to brown bears in Europe, North America and Asia, Apennine brown bears have distinctive facial and head features, a smaller body and are less aggressive.
“One of the main causes of the decline and isolation,” said Andrea Benazzo, a biologist at the University of Ferrara, “was probably deforestation associated with the expansion of agriculture and the increase in human population density in central Italy.”
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Benazzo is the lead author of a study recently published in Molecular biology and evolution. He and his colleagues at the University of Ferrara used genomic analysis to study how humans have recently altered the evolution of the Apennine brown bear. Not surprisingly, they found that Apennine brown bears had less genomic diversity and greater inbreeding than other brown bears due to their isolation.
“More interestingly, however,” added study co-author and molecular biologist Giulia Fabbri, “we showed that Apennine brown bears also possess selective signatures at [the] genes associated with reduced aggression.
Their results indicate that selection for behavior-related genetic variants – likely driven by humans’ removal of bears with greater aggression – favored a significantly less aggressive bear population. They also suggest what might seem like a paradox.
“The general implications of our results are clear,” said Giorgio Bertorelle, study co-author and geneticist. “Human-wildlife interactions are often dangerous to the survival of a species, but can also promote the evolution of traits that reduce conflict,” he added. “This means that even populations that have been strongly and negatively affected by human activities may harbor genetic variants that should not be diluted. »
