Darren G. Davis 
Lost Raven #1 [EPUB ebook] 

Zak Raven is through with the 9-5 grind and is now an ex-attorney on a mission to relax. However a peaceful trip goes really wrong when he get shipwrecked on what he thinks is a deserted island. His only companions are his own words in his journal. Unknown to Zak, four miles below the surface secretly hides a government experimentation center where scientists are playing God by trying to artificially evolve a human based species that can survive evacuation missions in deep space. Within 900 years, earth will be dealt a deathblow by a mountain-size asteroid. However, so far they have only achieved creating living abominations. Zak and these creatures are on a collision course, and he must rise to the challenge!