What survives the alternating pressures of these two processes is that genetic material which has proven not to be disadvantageous. For cybernetics, evolution is the process in which variety is alternatingly generated and destroyed so that which survives is not being effected by either. It applies to the interaction between species or organisms and their environments, not to particular organisms. Evolution lets survive all those organisms that do not develop or exhibit disadvantageous properties. It does not favor the fittest.
Evolution is an opportunistic process, neither progressive nor guided by any particular goal.