Orphan Black is very much science fiction, but it tends to err on the side of science fact or, at the very least, extrapolating from where we currently are with technology and genetics. That's largely thanks to the IRL Cosima who, along with being a general science advisor for the series as a whole, also put the writing staff through a brief history of cloning techniques before the show started. The sort of IVF-derived cloning in Orphan Black are mostly based on the technology that birthed Dolly The Sheep, the infamous duplicated farm animal created in 1997. That technology has never actually been used to clone humans...yet. Most of that is because in most countries there are laws against the cloning of human beings or experiments regarding such. Whilst those laws are still in effect (and indeed the covert operations in the show will attest to that), Dolly proved we're not far off being able to copy a person. Graeme Manson demanded when they began writing the show: start with hard science and drive with character. Even the idea that the clones have different fingerprints comes from real-life science, and the timeline for cloning technology coming into being on the show is about right.
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/
