The number of different evolutionary pathways available to populations adapting to a new environment depends on the range and characteristics of possible genetic solutions. Even populations adapting to the same environmental challenge can diverge genetically from each other if different mutations happen to establish. The long-term impact of this initial divergence depends on the fitness interactions between the available alleles that underlie adaptation to a given environment (“epistasis”).

The number of different evolutionary pathways available to populations adapting to a new environment depends on the range and characteristics of possible genetic solutions. Even populations adapting to the same environmental challenge can diverge genetically from each other if different mutations happen to establish. The long-term impact of this initial divergence depends on the fitness interactions between the available alleles that underlie adaptation to a given environment (“epistasis”).