How do you clone a dog like they did on the Channel 4 programme “The £60,000 Puppy: Cloning Man’s Best Friend” shown this week? It might seem obvious to some, but for the great majority cloning sounds like something out of science fiction. Let’s break it down as simply as possible. DNA is the recipe that is used by almost all of life on Earth. Every single animal that has ever lived started as a single cell and developed into an adult by following, very precisely, the instructions in its DNA. Using delicate processes scientists are now able to remove the DNA from an embryo, leaving a healthy but information-less cell. The DNA is then taken from a living individual and inserted into the empty cell, replacing that which was removed and giving it instructions to create an adult. This embryo is then implanted in a female and the pregnancy and growth begins.
So an individual’s unique DNA specifies precisely how to ‘make’ that individual from the starting point of an embryo. By replacing the recipe from one embryo with that of a living individual, a clone is produced that is essentially an identical twin, just with a different birthday to the original. This does not mean that the clone is the exact same individual – just look at typical identical twins – they are made individual by the environment they experience through their lives.
Cloning cannot recreate an individual’s personality; it cannot make a copy of a person; it cannot bring someone back from the dead or let them live forever. However, it could be used to exclusively breed the most desirable and valuable animals for agriculture, albeit at greater risk of epidemics.