Chemical evolution at the primitive prebiotic level may have proceeded toward increased diversity and complexity by the adjacent possible process (originally proposed by Kauffman). Once primitive self-replicating systems evolved, they could continue evolution via Eigen's hypercycles, and by Prigogine's emergence of order at the far-from-the equilibrium, non-linear systems. We envisage a gradual transition from a complex pre-life system, which we call the transition zone. In this zone we find a mixture of complex chemical cycles that reproduce and secure energy. Small incremental changes in the structure and organization of the transition zone eventually lead to life. However, the chemical systems in this zone may or may not lead to life. It is possible that the transition to life might be the result of an algorithm. But, it is uncertain whether an algorithm could be applied to the systems in which chance plays a role.