A Pre-pattern formation mechanism for animal coat markings

It is generally accepted that colour patterns in animals are genetically determined but the mechanism is not known. We suggest that a single mechanism which can exhibit an infinite variety of patterns is a candidate for it. We thus propose that a reaction-diffusion system which can be diffusively driven unstable could be responsible for the laying down of the pre-pattern for animal coat markings.

For illustrative purposes only we consider a specific practical substrate inhibition reaction mechanism in detail and show that the geometry and scale of the domain, the relevant part of the integument, during the time of laying down plays a crucial role in the structural patterns which result. Patterns which exhibit a limited randomness are obtained for a selection of geometries and are specifically related to the coat colour distribution in the spotted felidae, zebra and other animals.