I have been trying to remember the name and author of a book I read 20 or more years ago. I remember it starts with a number of humans abducted from contemporary earth in a large alien starship. They are taken to another world and deposited in a large enclosure surrounded by a forcefield, with a pristine wilderness inside for them to inhabit. They can make out other enclosures around theirs; apparently it's a habitat or zoo. The only other thing I recall is that somehow they escape the enclosure and are stranded on this world. The final scene is a rocket launched by their descendents to begin a search for Earth. I hope this is familiar to someone, as I remember this was one of the most satisfying reads I'd ever had at the time.