Escaped pigs speed wild boar breeding after Fukushima nuclear disaster

Following the 2011 Fukushima nuclear disaster, thousands of domestic pigs escaped into nearby forests and began interbreeding with local wild boar populations. Researchers from Fukushima University and Hirosaki University studied this unplanned hybridization and discovered a unique genetic mechanism driving rapid population changes. Specifically, the fast-breeding trait of domestic pigs—characterized by year-round reproduction—is inherited maternally. When female domestic pigs bred with wild boars, their hybrid daughters inherited this accelerated reproductive cycle, causing a rapid turnover in the hybrid population. However, rather than permanently introducing domestic pig genes into the wild boar gene pool, this maternal-driven rapid breeding paradoxically accelerated the dilution of domestic DNA. Because these hybrids bred so frequently, their descendants repeatedly backcrossed with the larger wild boar population, quickly filtering out domestic nuclear genes within just a few generations. As a result, the population physically resembled wild boars but retained the high reproductive rate of domestic pigs. The study, published in the Journal of