«This is probably the result of differing fitness costs of the mutations,» says Günthard. (sciencedaily.com)
Such fitness costs associated with strict specialization mean that the all - rounder strategy probably has the better prospects of success in a natural environment with slave - makers. (sciencedaily.com)
«Certain flu virus mutations may compensate for fitness costs of other mutations: Unexpected mutations help flu virus retain fitness by counteracting changes needed to dodge the immune system.» (sciencedaily.com)