Palimpsest

"Palimpsest" by Roger D. Aycock is a science fiction story from the 1950s that looks at where humans come from, staying alive, and who we are, through the eyes of a spaceship crew on their way to make Venus their new home after Earth is gone. These Earthmen, led by Val Conna on the Terra IV, soon find out Venus already has people -- descendants from a previous mission led by the Connors; adding to the trouble is Hanlon, a troubled stowaway with identity issues. As the crew struggles with the weight of Earth's destruction and the task of starting a new human race, they deal with their own doubts. The journey ends with a shocking truth about where they all came from, which challenges everything they thought they knew about being human.