Humans have long been performing scientific experiments on animals, ranging from the innocuous to downright controversial.
Testing of drugs and cosmetics on animals have been the subject of protests in the West, but far more controversy and debate is generated whenever genetic modifications are performed.
While there are laws prohibiting human cloning and genetic modifications in countries such as the US, UK, Canada and Australia, there are no such laws for animals.
The ethics of practices such as transgenic modifications - introducing a gene into a living organism so that the organism will exhibit a new property and transmit that property to its offspring - is often debated.
Some of these famous modified animals have also been cloned, resulting in offspring that have inherited special qualities.
An example of this type of experiment took place on April 26, 1999, when researchers genetically engineered goats to produce a human protein used to affect blood clotting - and then cloned the goats. Read more about it here.