"Ban the clones ? Does all this mean that the possibility of human cloning should be joyously embraced ? Far from it . It would be suicidal , not just dispiriting , for the species to give up sexual reproduction in favour of cloning . Sex creates new gene combinations that confer new strengths , especially resistance to disease . As a distinguished biologist , George C. Williams , put it many years ago , asexual reproduction is like xeroxing your lottery ticket ; even if you have the winning number , making many copies wo not help unless the winning number is the same every time . In the history of evolution asexual lineages of species have often appeared but few have lasted long."