Genesis Quest Series by Donald Moffitt

Although Earth is millions of miles away, bioengineer Bram is determined to discover the truth about his species and the land that has been kept secret his whole life. He must discover a way to unveil the truth and see the homeland he has been denied.

Many centuries ago, an alien race known as the Nar was able to recreate human beings from genetic code, broadcast from Earth into outer space by a beleaguered humanity. They allow a group of humans to travel millions of light years through the galaxy, in order to discover what has happened to the original occupants of planet Earth. However, none of the human participants of the expedition are prepared for what awaits them at the completion of their journey...