Snapdragon on Tamariu Granite

This beautiful flower has been a model for genetic studies for about 75 years, posing shamelessly for legions of scientists. The snapdragon flower colors do not mix, even if they are growing together in a wide area. Selection has favored new variants at the color genes, making the flowers more attractive to bees, causing these genes to sweep through the population, and leaving a sharp signal in the DNA sequences. The flower genes become barriers to gene exchange. Genes located close to the flower genes cannot easily be swapped between the populations. There are three classes of these flower genes, A, B, and C, which control the sepal and petal, the petal and stamen, and the stamen and carpel respectively.