Artificial embryo twinning is a method of making clones that mimics the natural process of creating identical twins, according to the Genetic Science Learning Center. It uses the same approach as natural cloning, but it is performed in a Petri dish rather than inside the mother.
The GSLC explains that in nature, twins form quite early in development when the embryo splits in two. During the first days after the egg and sperm join, twinning occurs while the embryo is only composed of a tiny number of unspecialized cells. Both halves of the embryo continue to divide on their own, eventually developing into separate, complete individuals. The resulting individuals are genetically identical, as they were created from the same fertilized egg. This is the same way that artificial embryo twinning works, but the development is carried out in a Petri dish.
Artificial embryo twinning involves separating a very early embryo into individual cells, which divide and develop in the Petri dish for a brief period, says the GSLC. The embryos are then transferred into a surrogate mother, where they complete their development.
The Association of the British Pharmaceutical Industry explains that artificial twinning is a technological advancement on embryo transfer, which has been applied in the cattle industry for many years. The embryo is intentionally split early through artificial methods, and each resulting embryo develops into a fetus with its own placenta and amniotic sacs.