Social structure, geographic distribution, and inferred dispersal routes of modern wild boars. [Photo/news.hzau.edu.cn]

On Sept 25, the international academic journal Science published a landmark research paper led by Academician Zhao Shuhong's team from Huazhong Agricultural University and Yazhouwan National Laboratory, in collaboration with multiple domestic and international research institutions.

Entitled "Ancient introgression drives wild boar expansion and phenotypic diversification of domestic pigs", the study spans over a decade of dedicated international cooperation, systematically integrating global genomic resources of wild boars and domestic pigs across diverse geographic regions.

The research fundamentally reconstructs the classical "island origin" model of modern wild boars that has been adopted by scholars worldwide for nearly half a century. It relocates the origin center of modern wild boars from "island Southeast Asia" to the "tropical Asian mainland", suggesting that South Asia and China's southwestern Himalayan region likely served as pivotal areas for their origin and early divergence.

Furthermore, the findings reveal that ancient gene flow originating from South Asia played a crucial role in driving wild boar body size evolution, cold adaptation, and geographic expansion, while providing empirical support for the classical evolutionary biology theory known as Bergmann's rule from both genetic and causal inference perspectives.

By connecting ancient interspecific gene exchange, natural selection, and modern artificial selection, this comprehensive work establishes a robust theoretical foundation and valuable target resources for the collaborative genetic improvement of meat production and environmental stress tolerance in domestic pigs.