Can cloning occur naturally?
Yes, cloning occurs in nature and can occur in organisms that reproduce sexually as well as those that reproduce asexually. In sexual reproduction, clones are created when a fertilized egg splits to produce identical (monozygous) twins with identical DNA. While this is a relatively rare event, many species produce their descendants asexually, that is, without the combining of the male and female genetic material that occurs in sexual reproduction; such offspring are clones of their parent. Since mammals do not normally reproduce asexually, the birth of the lamb Dolly at a research institute in Scotland in 1996 was the first reported mammalian clone produced asexually.
