Natural selection: Mutations (e.g. of pigment gene, and of regulatory genes) creating variability between members of the same species. Selection pressure of prey availability - Selection pressures are external agents which affect an organism’s ability to survive in a given environment. The adaptation helped tigers hide from prey / ref to camouflage. Striped tigers had a greater survival probability and were more likely to reproduce. Beneficial alleles were passed on to the next generation. The allele frequency for the relevant genes would have increased with each generationAfter many generations, all tigers within a population were striped Roles of regulatory genes (regulatory) genes control, the pattern/ where pigments produced / expression of other genes Genes switched on or off during development (i.e. epigenetic changes / transcription factors)Anatomical adaptation