I do not believe in creationism -if that is the definition.
The definition provided is not consistent with what is written in the bible.
Proof of the possibility of creation is mankind's ability to create.
We manipulate natural processes to rearrange matter into other things, etc.
We manipulate the elements and forces now available to manipulate, and also set in motion chain reactions of natural processes toward a predetermined end.
Both specific acts of creation and natural processes are known to exist -it is just a matter of which are responsible for what.
God is credited with creating the very natural processes by which we exist and which we manipulate. He would have done so by manipulating whatever existed before that (even if that is a rearrangement of what he is) -that which was nature prior to the present nature we know -which we know was produced by a process.
Being the creator of all things -the one by who all things consist -the one who framed the worlds -would mean that he set in motion the process which created the elements and forces, and all that was produced by them.
That would include evolution if evolution required no specific acts of creation after the initialization of those processes.
We, ourselves, are proof that natural processes can be manipulated to create life -as we have reverse-engineered it and created synthetic DNA, etc.
There is no creation -even divine -which does not involve manipulating natural processes, as everything that exists is "nature".
There would, however, be a difference in how God created as opposed to man, because man is limited to that which can be manipulated by the body, and any extensions (tools, etc.) man can create with the body.
God is described as able to create directly by will -by fiat -having a direct interface.
Whereas we think, then move our bodies to manipulate things -he is able to manipulate them directly -but they are still "natural".
When we synthesize DNA, it is both specific and natural.
God creating DNA would also be -but knowing which things happened by decision at which point would likely be impossible at this point. His decision to cause life to emerge could have predated the universe -even intentionally encoded in the "Big Bang", and could have been done by setting in motion the natural processes inevitably resulting in the emergence of life -or he could have also acted specifically afterward. It would be difficult to determine -just as our activities or identity could be a mystery to any life we might seed on another planet....
As for the specific acts spoken of in Genesis, they do not actually refer to the very beginnings of life on earth.
They are specific acts which even man is nearly able to do (though not by fiat).
It is not inconceivable that we could produce certain specific types of life on earth after surviving an extinction event -after their kind.
We are also nearing the ability to do other things described in the bible which have seemed ridiculous....
Causing a lion to eat straw like an ox -causing poisonous snakes to be non-poisonous and eat matter from the dust of the ground.
Natural processes -such as DNA self-replication -can be designed and set in motion (can be specific acts of creation) which do not need continuous specific acts of creation to change -though they can still be subject to specific acts afterward.
Short of meeting God, it is not likely we could prove exactly what did or did not happen in the past.
If the same things which might happen by "natural" things occurring in a specific order can also happen due to specific acts ordering things specifically, how could we know whether or not there was intent behind any specific occurrence?
We can only know that something was created by man by when it is not similar to that which occurs in what we call nature -but we do not have the same reference for that which might have been created by God -especially if God essentially is nature. We could not see the forest for the trees, as it were.
Perhaps the universe is dissimilar to that which occurred in the nature which preceded it -making the universe itself the proof of God's creative activity. We're just not there yet.