In a PNAS study, a team based in Portugal, the UK, and elsewhere consider the history of invasive rabbits in Australia that originated in Europe. After analyzing available genetic and historical data, the researchers suggested that the most successful rabbit interlopers are descended from wild rabbits with an advantageous genotype that were brought to mainland Australia by an English settler in the 1850s. In contrast, they explain, other rabbit introductions "established local populations but have not spread geographically." Together with data from Tasmania and New Zealand, the results suggest that "the common denominator of these invasions was the arrival of a new genotype that was better adapted to the natural environment," the authors note. "Before the arrival of this lineage, numerous earlier introductions failed to spread, suggesting that the genetic composition of the introduced individuals played a crucial role in determining the invasion's success."