Before revision: Though the problem of pattern formation in biological systems has been studied  more than sixty years, it is from the beginning of this cen- tury that the synergy between theoretical and experimental researchers are depicting the ins and outs of this problem.
After revision: Though the problem of pattern formation in biological systems has been studied for more than sixty years, it is from the beginning of this cen- tury that the synergy between theoretical and experimental researchers are depicting the ins and outs of this problem.