How humans made Marsican brown bear more docile over centuries (DNA proves it)

In the eyes of scientists and enthusiasts alike, Marsican brown bears have always been considered a precious and unique species, distributed throughout the apennine areas of the Botte. Smaller in stature than their northern Italian cousins, these specimens also possess a more docile temperament, having evolved over time. Their DNA bears witness to this evolution.

This is the finding of a recent scientific study published in the journal Molecular Biology and Evolution, which investigates the nature of these wild animals and the factors that have influenced their evolution.

Comparing the genomes of various brown bear specimens from Central Italy, Europe and North America, the researchers focused their attention on the Apennine bear population and carried out analyses on specific samples. The results indicate that the genetic diversity of Marsican brown bears is associated with reduced aggressiveness, and therefore with particular genes.

The research revealed that the behavior of Marsican brown bears, a subspecies of the brown bear, is the result of a singular evolutionary process, not without its consequences and grey areas.

In fact, it's not surprising that these bears "went their own way" over 2,000 years ago, at a time when the impact of human activity began to diminish their habitat.impact of human activities began to reduce their territory and, in so doing, reshape the habits of many wild species, including bears.

But how, and above all, by what mechanism could the behavior of Marsican brown bears have been influenced, to the point of making them less aggressive than their congeners? For researchers, this change must be interpreted as a response to anthropogenic pressures: an ability - which has become a necessity - to adapt in order to survive in an increasingly reduced and disrupted habitat.

To better understand this process, it is useful to look back at the dynamics at work in the region. In the case of Apennine Italy, one of the main transformations was deforestation linked to the development of agricultural activities and urbanization, with the creation of small and large villages. These changes led to the isolation of the Marsican brown bear population for over 1,000 years. But that's not all.

Certain historical practices would have been added to this isolation, which unfortunately have not totally disappeared today, and which could have had a major influence in shaping the temperament of Marsican bears. Among these was the killing of bears deemed the most dangerous, held responsible for attacks or damage. If persecution of bears is attested as far back as Roman times, this repeated selection by human beings, combined with the elementsmay have led Marsican bears to adapt their behavior to escape death, avoiding potential conflict situations wherever possible.

Bears are therefore more peaceful, more tolerant of human presence, but also more exposed to all kinds of dangers. Traces of these modifications can be seen in the genome of these animals, a major finding for specialists.

The lights and shadows of adaptation

Observations made both in the wild and in urban environments continue to show that these plantigrades do indeed have a lifestyle different from that of other brown bears. But the price to be paid for this selection is high, very high indeed.

We know how difficult it is for bears and humans to cohabit in anthropized territories. It's not just a question of the threats these animals face, but also of the consequences of past practices that continue to reverberate in the present. As Professor Andrea Benazzo, a lecturer at the University of Ferrara and one of the study's authors, explained in an interview:

"Our work highlights demographic decline and genetic erosion, linked to the very limited number of individuals. A result that has direct implications for conservation."

The low genetic diversity and high rate of inbreeding that characterize these bears remain a source of concern for scientists. It should be remembered that this population is classified as in danger of extinction due to the decline in the number of specimens.

While on the one hand, this new scientific work contributes to a better understanding of the species and its evolution, on the other, it raises new questions about the future of the species.tions for the future of these animals, while reaffirming the importance of protecting Marsican bears in a broader conservation perspective. Their fate is in our hands.

Today, according to data collected by technicians from the Abruzzo, Lazio and Molise National Park, the birthplace of the Marsican bear, some 50 individuals live within the protected area. Studies are currently underway to obtain a more accurate and up-to-date estimate of this population.

Source: Molecular Biology and Evolution