Far be it from me to accuse Paul Davies of “overthinking the problem”, but let us consider that possibility.
Firstly, on the positive side, we’re all agreed that the bizarre complexity of life only makes sense in the context of evolution. Natural selection has produced a cornucopia of survival and improvement mechanisms.
Now consider this: The bigger the selective advantage of a mutation, the more quickly it will rise to dominance. Something like a “nerve” that can quickly send information (about food or a threat) to remote parts of an organism? Wham! Instant success! And a brain? Whoa!!
Summary so far: Given life, evolution explains the rest.
Paul Davies agonises over the remote probability of life beginning in the first place. I do not, because I already know of the organising power of inert materials. So do many physicists. These materials have different names in different domains, but I call them “substrates” - the right kind of clay, a particular crystalline material, something to anchor one material in a useful pattern while others extend it. One organic material becomes a substrate for the next.
Substrates make pond slime possible, and pond slime makes life possible.
That’s why I think there is, was, or will be life elsewhere in the universe; no transcendent principle is required; however the combined tyrannies of time and distance make it almost certain that in the little time left for us, we will never discover it.