CNET también está disponible en español.

Ir a español

Don't show this again

Christmas Gift Guide

Send in the clones

Like Orphan Black's Project Leda, we're already cloning all over the place

Genome advancement

Scientists already have created proto-Sarahs

We've done it more than once

We could go even further...if we wanted to

But it would risk some serious Cosimas

Like Sarah, some clones have given birth...

But like Helena, some clones actually look very, very different

And like Alison, clone personalities can be very, very, VERY different

It's official: The BBC sci-fi hit Orphan Black is coming back for a fourth season. Get ready for more clones on top of the many we already know, including Sarah, Helena, Alison and Cosima.

The showrunners are already promising new twists -- as if trans clones and a revolving door of psychopaths haven't been enough.

It's outrageous fiction, of course. But when it comes to the science of cloning, the show is closer to fact than you might think.

Caption by / Photo by BBC America

At least, when it comes to animals. Everyone knows about Dolly, the very real cloned sheep born in 1996 to Scottish scientists. But since then, clones of other animals have emerged, including...

Caption by / Photo by Getty Images

...pigs, deer, horses and bulls.

A la the creepy Prolethean cult in Orphan Black, we're also sequencing the heck out of all kinds of genomes for the purposes of disease fighting and, yes, cloning.

This thoroughbred, Twilight, is a mare from Cornell University in Ithaca, N.Y. Researchers supported by National Human Genome Research Institute sequenced an equine genome using a small sample of blood from the horse.

Caption by / Photo by NHGRI

Has mankind successfully cloned itself? By all accounts, we have yet to produce a fully gestated cloned human baby.

But we have created proto-people. In 1998, workers at Advanced Cell Technology took a nucleus from a man’s leg and inserted it into the ovum of a cow. The resulting embryo was destroyed after 12 days.

Caption by / Photo by BBC America

A decade later, scientists were at it again. This time, the company was Stemagen, and the five embryos they created reached a more mature stage before they were destroyed.

Caption by / Photo by Matthew Pace/Getty Images

Unlike Canada, parts of Australia, Colombia, Romania, and Serbia, the United States has no federal law on the books specifically prohibiting human cloning. If scientists wanted to bring one of those aforementioned embryos to term, there would be no all-encompassing law that could completely stop them...though many individual states do ban human cloning.

Caption by / Photo by BBC America

The most commonly referenced type of cloning -- implanting a somatic cell nucleus into a prepared egg -- is very risky. Even if implantation goes fine, the subsequent development of the clone is not always guaranteed. Dolly sprang from the 277th attempt at sheep cloning, but she died soon after reaching age six, about half the life expectancy of a typical sheep.

Veterinarians gave Dolly a lethal injection in 2003 after they discovered signs of progressive lung disease.

Her story is echoed in the health problems of the chronically ill Orphan Black character Cosima.

Caption by / Photo by BBC America

Except they're not people either. This kitten, CC, born in 2001 at Texas A&M University, grew up to bear four kittens of her own. Three of them were born alive.

Caption by / Photo by Texas A&M University/Getty Images

When you think clones, you think look-alikes, right? Wrong. CC's biological mother, Rainbow, had a fur pattern different from CC. The reason: a natural genetic reprogramming that happens between cell fertilization and implantation.

Caption by / Photo by BBC America

Rainbow was different from CC in another way, too: Her personality. CC is described as curious and playful, while Rainbow, who passed away several years ago, was more reserved. No word on which cat looked better in purple.

Caption by / Photo by BBC America
Published: