Excellent question Serge! The difference is that an autogen, and all the more complex organisms that would have evolved from it, has crossed a threshold of actively "trying" to resist its own degeneration. It achieves this through the reciprocal constraint mechanism resulting from the coupling of two passive chemical processes. You could say that a system can be regarded as actively resisting its own degeneration if it persists much longer than would otherwise be expected in its environment. Of course, it's still entirely mechanistic and no laws of physics have been violated.