For example, sperm from a woolly mammoth could be used to fertilize an egg from a modern-day elephant. The fertilized egg would then be placed in the live female elephant where it would live and grow until it is ready to be born. The second method involves a type of cloning. In cloning, The DNA of one individual replaces the DNA of another. In the woolly mammoth example, scientists could inject DNA from a mammoth into an egg cell from an elephant. The cloned egg cell would then be placed into a living elephant and allowed to develop in the same way as a fertilized egg