The Yesterday Tree is a unique story about a group of humans 500 years in the future who are sent back to our time in order to find a cure for a genetic disease threatening to decimate their population. It really is a unique concept, and I love the fact that it deals with creating family trees. I'm a huge genealogy nut, so this really spoke to me. Unfortunately, there's so much unused potential with this novel.
The biggest issue I had with the book was that it read very much like an unedited draft. I don't comment on something like this unless it takes away from my reading experience and, unfortunately, it did. Not only were there numerous mistakes, the characters were, on the whole, unbelievable and inconsistent. Most kept flipping back and forth, being paranoid one minute and totally accepting the next. Even Warren was terrible. I don't think I've ever met a military man like him before.
Going back to the unused potential, Joan and Mike were characters who didn't really seem to be needed. If they had been taken out, the book wouldn't have changed at all for me. Joan was only used within the last 20 or so pages. It makes sense to have a linguist on the team, but they could have used her far before then.
Overall, the book is unique enough that I can say I've never read something like it. Not really. I've read about time travelling but to incorporate it with genetic history was interesting. With another very thorough edit I think this book would be very close to amazing.