Before revision:  The mechanism of such dynamical pattern selection is clarified on the basis of both numerical simulations and theoretical analyses, finding that successive emergence of local defects plays a critical role to realize the wild-type pattern . Physical and biological implications are also discussed .
After revision:  The mechanism of such dynamical pattern selection is clarified on the basis of both numerical simulations and theoretical analyses, finding that successive emergence of local defects plays a critical role to realize the wild-type pattern .