Poison-resistant 'super' mice evolving
Some house mice in Europe have evolved to be resistant to even the strongest of domestic poisons, according to research scientists.
Professor Michael Kohn from Houston's Rice University, who led the team that carried out the work, said that German and Spanish mice have evolved the trait quite quickly through breeding with an Algerian species of mouse.
The research, published in The Current Biology report, showed that the mice that were products of this breeding were resistant to almost any form of pest control, including warfarin, one of the most common poisons.
"Our study is so special because it involves hybridisation between two species of mouse that are 1.5-3 million years removed from each other," he said. "Most of the offspring do not reproduce, they are sterile - but there is a small window, which remains open for genes to be moved from one species to the other, and that's through a few fertile females - so there is a chance to leak genes from one species to another."
Increased human travel is thought to have brought the species together, while attempts to eradicate them with poison have put them under evolutionary stresses.