Desmond Bradley

Abstract Development depends on precise shaping of molecular gradients, but how natural selection acts to establish precision is unknown. Here we analyse genes that control differences in the gradient of yellow flower colour between two varieties of snapdragon (Antirrhinum). We show that these differences depend, in part, on cis regulatory variation in the pigment biosynthetic gene, FLAVIA (FLA).

Abstract Species can be considered to occupy different peaks in a fitness landscape, visualised as an undulating surface, with height corresponding to fitness and horizontal coordinates to genotype. A key evolutionary problem is to understand how populations traverse fitness valleys to reach different peaks. Hypothetical solutions include shifting balance theory, peak movements due to environmental changes, or peak connectivity in high-dimensional fitness spaces.

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