Reincarnation, at least as I conceive it, does not nullify what we know about evolution and genetics. It suggests, however, that there may be two streams of evolution -- the biological one and a personal one -- and that during terrestrial lives these streams may interact.
Ian Stevenson, M.D. (2000). “Children Who Remember Previous Lives: A Question of Reincarnation, rev. ed.”, p.12, McFarland