It's so interesting. It was done over the course of decades by the company that made Dolly the cloned sheep all those years ago. There are a handful, maybe a

It's so interesting. It was done over the course of decades by the company that made Dolly the cloned sheep all those years ago. There are a handful, maybe a dozen genetic changes that were needed, but that's not the most interesting part. Endemic to the general swine population are several retrovirus'. They are communicable, so they had to create an entirely separate breeding population of these pigs, with the genetic modifications, and then raise and otherwise maintain a breeding population that is totally separate from other farms. Something as simple as a feed truck delivery could lead to a compromise. Think about a farm, but total microbiological isolation.