Many extinct species are dead, but their DNA can be. recovered from samples and fossils in museums, even those up to 200,000 years old. 7. We can preserve species through the use of genetic engineering and reproductive _______. 8. Before cloning any animals, scientists must _______ that the animals can live their lives well in this world. 9. Many people believe that cloned mammoths might ______ problems to our ecosystems. 10. I’d like to know whether humans have ethics to clone other animals. Do we have moral obligations to do it?