Top Story, BioPharma

A new biological twist in Orphan Black: Cloning meets vanishing twin syndrome

The hunt for both the Leda and the Castor clone originals has turned out to be a two-birds-one-stone situation.

Since the beginning of the Orphan Black series, we’ve wondered where the Leda clones came from – who the original was. And now that we’ve been introduced to the male Castor clones, the same question remains.

Sarah has been set on getting to the bottom of this, too, and for that reason, she Felix and Siobhan headed to London in “Insolvent Phantom Of Tomorrow,” where they planned to look for the original Castor based on information Rachel gave them.

It was a plot-packed episode as a whole. Helena murdered a few people who threatened Alison and Donnie, for example. But the biggest revelation came at the end when we actually found out who the original was for both the Leda and Castor clones.

That’s right, the original for both.

The Castor number that Rachel gave them ends up identifying Siobhan’s mother, Kendall – as if the genetic overlaps could get anymore complicated. We’ve known that Siobhan wasn’t Sarah’s actual biological mother, but now, it turns out, they are indeed related, just in a weird, twisted way.

Kendall is a genetic chimera. She reveals to Siobhan and Sarah that she was a twin and absorbed the male twin in utero, meaning she has both sets of DNA. She was the sole progenitor for both sets of clones.

Often referred to as vanishing twin syndrome, this happens in real life, and it’s not necessarily as rare as some might think. As American Pregnancy states, vanishing twin syndrome occurs in 21 to 30 percent of multifetal pregnancies. It’s not often the case that the remaining twin gets both sets of DNA, but it happens.

Apparently the cloning project wasn’t experimental enough for Dyad. Might as well pull the DNA from the same person so that everyone is part of one big happy family.

It isn’t clear if cloning both the male and female clones from the same source has some sort of biological advantage for the process, or maybe it just provides a more controlled experiment.

Regardless, the fact that Sarah now knows that the Castor clones are her actual twins, as it were, it might change her approach with them and vice versa, assuming she shares the information with everyone. Maybe the clones won’t be out for blood as much within the same gene pool and could actually team up against Dyad, and more specifically, Ferdinand.

This might be slightly too optimistic.

Hopefully we’ll get more answers in next week’s season finale, but we can probably assume another cliffhanger awaits us.