Artificial embryo twinning is also called embryo splitting. This way of cloning mimics the way natural twins occur. Artificial twinning is really a technological advancement on embryo transfer, which has been used in the cattle industry for many years.

 

Natural twins occur when an embryo splits in two. This happens a few days after the egg has been fertilized. The reason this happens so early on is that the cells are still not specialized at this point meaning that the individual will not suffer damage from the embryo splitting.

 

In artificial twinning the egg cell is taken from the biological mother once fertilized. Once the cells inside the embryo start splitting (still inside one embryo) some cells are then seperated and developed in a petri dish. Then they are placed in a surrogate mother.