Changing the number or gene content of chromosomes in an organism is assumed to have grave, often fatal, consequences. However, scientists from the Institute of Animal Physiology and Genetics CAS have discovered that some animals do not mind such changes, but instead, they benefit from them by developing novel traits. Thanks to a unique study of asexual reproduction in loaches, experts have described the evolutionary processes of intracellular gene conflict leading to the emergence of new species that are successful in changing environments.