Actually, the evidence seems to be on the contrary: the very first pasuk suggests already that it was written by someone not God as the creation story is written in the third person:
"In the beginning, God created heaven and earth."
Or, in the 'original':
בְּרֵאשִׁית, בָּרָא אֱלֹהִים, אֵת הַשָּׁמַיִם, וְאֵת הָאָרֶץ
Notice that it says "God created" and not "I created"!
To which I can only say: "Open my eyes, that I may behold wondrous things from your Torah"!