Well there are theories and evidence about how life can spring from non-life... is there a clear definition of what constitutes life? At what point to proteins and acids and molecules go from a chemical reaction to 'life'. (maybe when high voltage electricity runs through proteins?)
It's tough to prove we aren't just a very complex (to us) chemical reaction.
And being able to 'explain something concretely' and 'having evidence that points to a conclusion' are not the same thing, but latter often preceeds the former.
All science does is gather and analyze info... when certain people inject their philosophy into the mix - that is no longer scientific. So a true scientist would never say 'There is no design, no 'hand' in evolution of life, or universe... he or she could only say we have no reason yet to think that way.
Just as a scientist would never rule out God's existence, as there is no proof he doesn't exist, nor even any evidence he doesn't exist... Scientifically, we're in a situation that science has yet to support his existence...ergo, it should be left out of the discussion like anything else that has no evidence for or against it.
The origin of life requires a catalyst like the origin of everything else in the universe.
We don't know what that is. But over time... scientific progress will shed more light, as it is unlikely to shed less light, or the same amount of light.