THE EVOLUTION OF SPATIAL DIFFUSION

The mobility of members of a species, which may be modelled by diffusi on, plays an important role in biology, though much remains to be disc overed concerning its effects. It is therefore relevant to ask how dif fusion itself may evolve, in particular in a spatially homogeneous env ironment. The authors suggest that one mechanism driving the evolution of a higher diffusion rate is connected with the effect of a deleteri ous recessive gene which appears in the population. A reaction-diffusi on model is proposed, and numerical and theoretical results are presen ted which support the above hypothesis.