That may be. There are a number of emergent function type models out there (a la Wolfram--he wasn't first, you know!). But we don't have any molecular evidence for "other factor(s)". We haven't found a secret supergene, present from the time of the putative UCA, that hypermutates and recombines into genes, just so, in times of need. We haven't found a heavenly mosquito that injects the appropriate genetic sequences to allow for adaptive mutations. We haven't discovered any mechanisms that allow DNA repair systems to overlook specific mutations that will lead to new features. So, we are left with a model that supports genetic change on a probabilistic level that indicates no directed change even though we know there is bias based on structural, sequence information, developmental, or environmental constraints.
On top of all that, we already know, with massive amounts of supporting evidence, that natural selection that acts on variation exists. Any change, however it is induced, is subject to selection. Any other factors at work in evolution are still subject to selection.
Why would the primaeval fish "naturally select" for functions/capabilities that it didn't need to improve its survival fitness?
In other words, why are organisms evolvable? At one level because of the imperfection in replication. From a birds-eye view, that's a much larger question, of course. Why do the laws of physics and chemistry make it possible for this to happen? Why are things the way they are? I don't know if that's a question for which the answer can be found in evolution.
But this is my point, Nebullis. Does this then necessarily mean that because evolution cannot find the answer to these questions, then no answer can be found? And thus, we are to assume that, because we can't find the answers, then the questions do not make sense at all? So don't ask them?
Evolutionists often speak as if natural selection changes the odds of something occurring. It does not. Selection only works after the event occurs so it has no influence in the occurrence of a particular event. If the chances of an event occurring are 1 in 10^60 chances without selection they are 1 in 10^60 with selection. Selection does not create anything, it does not work before the fact which is what would be needed for it to change the odds. What it does do is leave a trail of death which makes the finding of the correct change virtually impossible. That is why selection is an agent of stasis not of evolution.