Scientists have learned about changes in the evolution of bears after living near villages

Scientists have discovered that brown bears living near human settlements in Italy have become smaller and less aggressive in the process of evolution. This was reported by Science X magazine on December 15.

The Apennine brown bear (Ursus arctos marsicanus) is a rare and isolated population found exclusively in Central Italy. She has been living in close proximity to a human for a long time. Previous studies have shown that this group separated from other European brown bears 2-3 thousand years ago and remained completely isolated since the Roman era.

"One of the main reasons for the decline and isolation was probably deforestation, associated with the spread of agriculture and an increase in population density in Central Italy," said Andrea Benazzo, lead author of the paper.

At the moment, the Apennine bears are noticeably different from other brown bears in Europe, North America and Asia. They have smaller body sizes, characteristic features of the head and muzzle, as well as a calmer, less aggressive behavior.

In the new study, the researchers focused on recent evolutionary changes caused by human activity. They created a high-quality reference genomic sequence of the Apennine brown bear and re-sequenced the complete genomes of several individuals. The data obtained were compared with the genomes of bears from a large population in Slovakia and with previously published genomes of American brown bears.

The analysis showed that Apennine bears have reduced genetic diversity and a higher level of inbreeding compared to other populations. Julia Fabbri, another author of the study, called it even more interesting that this type of bear has selective traits in genes that are associated with a decrease in aggressive behavior.

According to the authors, the selection of behavioral genetic variants was probably due to the fact that more aggressive bears were more often eliminated by humans. As a result, a population with a noticeably more peaceful behavior was formed.

These results, as specified, show the dual effect of human influence. On the one hand, it led to a reduction in the number and genetic impoverishment of the population, increasing the risk of extinction, and on the other, it contributed to the evolution of less conflictual forms of interaction between humans and bears.

"The general conclusions drawn from our research are obvious. The interaction of humans and wildlife is often dangerous for the survival of a species, but it can also contribute to the evolution of traits that reduce conflict. This means that even populations that have been severely and negatively affected by human activity may contain genetic variants that should not be diluted, for example, by restoring the population," concluded researcher Giorgio Bertorelle.

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On December 11, the journal PLOS One reported the discovery of a new species of miniature frogs of bright orange color in a mountain forest area in Serra do Quiri in southern Brazil. The amphibian belongs to the family of short-heads, and its body size barely exceeds 1 cm. The new species was described as Brachycephalus lulai, and the amphibian received its name in honor of Brazilian President Luiz Inacio Lula da Silva.

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