After the origin of life
SummaryAs to the primary morphogenesis which occurred after the origin of life, two conditions are considered.(a)It must be a non-specific pattern.(b)It must be one of the simplest patterns.
The above conditions are satisfied by the morphogenetic polarity. Actually, the simplest polar pattern is divided into two classes. The first of these is represented by a regional protrusion of the surface of a sphere (Fig. 1B), and the second by a regional inversion (Fig. 1C). That means that the first morphogenesis might take place towards two directions: regional protrusion and regional inversion of the globular organism. Both of them might be conditioned by the appearance of protoplasmic polarity.