Hyogo University, Kakogawa, Hyogo 675-0101, Japan
(Received November 19, 1999; Accepted December 22, 1999)
Keywords: Branching, Cell Pattern, Gene, Lateral Inhibition, Self-Organization
Abstract. Genes have been considered to determine biological shape. However, based on several studies of the self-organization of biological systems, I would like to point out that genes do not always determine biological shape directly, but produce dynamic units that are spontaneously assembled into a characteristic shape. The spontaneously assembling is affected by stochastic and environmental effects, and lead to the final shapes. Shapes of living organisms thus do not necessarily have an adaptive value. They are sometimes neutral.