This in no way is meant to deny of exclude the common interpretations of the unforgivable sin and is not meant as an alternative but as a corollary.
Gen. 1:2 “And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.”
Gen 2:7 “And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.”
(note purely for sake of completeness that the word breath used in 2:7 can also be translated spirit, though probably not Spirit [capital S])
I didn’t really need these verses (especially the second) for the question, but I thought they added an interesting thought to things.
Now the question is this: The unforgiveable sin is (along or apart from traditional interpretations) denying the role of God as creator. I don’t want to get into the philisophical reasoning as to why this may be, but I am sure someone may post their own idea about that. Evolutionary creation is fine, but to believe that the world came to be completely without God is to blaspheme against the Spirit and is unorgiveable.