Dolly the Sheep was the first mammal to be cloned from an adult somatic cell, created by scientists at the Roslin Institute in Scotland in 1996. She was cloned using a technique called somatic cell nuclear transfer, where the nucleus of an adult cell was inserted into an egg cell that had its nucleus removed. Dolly's birth marked a significant milestone in the field of genetics and biotechnology, raising ethical questions about cloning and its implications. She lived for six years and gave birth to several lambs before being euthanized in 2003 due to health issues related to her age.