Planarians and the reimagined Battlestar Galactica

There are not many scientists that dislike science fiction (SF); it kind of comes with the territory; a love for science generally means a love for SF. A true scientist has a high degree of curiosity about nature; you see, a practicing scientist extends the frontiers of knowledge with each experiment. When a scientist gets data, it is entirely possible that the ONLY person in the world who knows that little piece of information about the universe is the scientist who worked on it. Trust me, it is a great feeling. Another cool thing about research is that with each new discovery, a whole series of new questions are generated immediately.

As a result, explicitly or implicitly, the very first question that comes to the mind of the researcher is, “what if…?”

A logical consequence of this fascination with nature is to wonder about the “what ifs” of the universe in general, usually related to the future of science, new discoveries, new technologies or new ways of looking at nature. This curiosity can also be about novel, unforeseen applications and implications of current knowledge. In my view, this is what makes SF great; science fiction is the literary exploration of the whole universe’s “what ifs”; it is about the search for the kind of knowledge that humans cannot, for a variety of reasons, experience firsthand (yet).

My all-time favorite (so far) science fiction TV series is the new Battlestar Galactica (BSG). Do not get me wrong, I am a proud Trekker (a trekkie if you ask my wife), loved Babylon 5 and even liked the original 1970s BSG series! In fact, I prefer any SF TV show, however bad or even ugly, over any so-called “reality show” for example.

That said, the new BSG took it up a notch in terms of quality all across the board.  I suspect that not many people will disagree with this statement. The new BSG had obvious entertaining features; good story lines, action, the works. When most people hear the words “science fiction” usually the first thing they think about is space, rockets and lasers. That’s OK, but SF is oh so much more, and the new BSG illustrated this with distinction.

I find that good science fiction it intellectually stimulating as well. For example, there is a long tradition in the so-called “hard” science fiction of exploring biological and even sociological themes. One of my favorite examples of this is Isaac Asimov’s Foundation Series. The Foundation novels are based on a fictional science, psychohistory, which is based on a real scientific idea, the Boltzmann’s Kinetic Theory of Gases. Boltzmann’s theory is able to predict the collective behavior of an ensemble of billions of molecules, but cannot predict the specific behavior of an individual particle. For example, we can predict that if we open a bottle of perfume in a closed room, the smell will diffuse throughout the room (we can even predict how fast will it diffuse depending on how big is the room and on environmental conditions such as temperature, for example), but we cannot predict which specific perfume molecule will end up by the ceiling, at the floor or up your nose.

Similarly, psychohistory was supposed to be a highly mathematical science which could predict the collective behavior of societies (wars, revolutions, dictators, periods of peace and prosperity, etc.); however, it could not predict the actions of an individual person.

As my favorite Vulcan would say, “Fascinating…

A great deal of hard SF deals with the concept of “life as we do not know it”. This refers to life fundamentally different from our type of life. What would be the “other” type of life most different from ours? Artificial life! Everybody has heard of robots; they have a distinguished place in SF history. The most extreme robots are anthropomorphic robots which are indistinguishable from real humans in terms of cognition (artificial intelligence) or physical appearance.

BSG excelled in this respect; the series portrayed several types of artificial life in a realistic, scientifically sound way. Overall, these characters implicitly explored the question, “what is life?” in general and the question, “what is a human?” in particular. These artificial life forms were called Cylons; there were at least four general types in the new BSG, two humanoid types, the ones who ran the Cylon starbases and the type of Cylons who were indistinguishable from humans, including the hideous (not!) #6 and Sharon…

The other two types were “robot-like”, the centurions and the raiders; the former were loosely humanoid metallic robots and the latter were true autonomous fighter spacecraft, where the pilots and the crafts were one.

What does BSG has to do with planarians? there are several intriguing parallels.

An aspect of the series that I find somewhat reminiscent of planarians is that the Cylons are practically immortal. When they die, their consciousness is downloaded into a brand new body; but, is the “resurrected” Cylon the same person? Atom by atom, in a physical sense, we are talking about a completely different entity, yet they certainly feel that they are themselves right? Something very similar happens to you too! Each year, about 98% of your atoms are replaced. In a very literal sense, physically, you are not the same entity that you were 10 years ago and yet, you are the same person!

Or are you?

In comparison, if you cut a planarian in several pieces, each part will eventually form a complete worm; one could ask, which one of the new planarians is the original one?

Another one: In 1969 the biologist H.V. Brønsted published the book Planarian Regeneration. In the preface, the author recalls a comment by a friend, “When you have done an experiment, then go through the (scientific) literature until you have found that your experiment have already been performed by others. Only then can you be sure that you have been through the entire literature“.

This is similar to one of my favorite lines in the whole BSG series which is one of its themes, “All of this has happened before and all of it will happen again“; just like Brønsted said above!

Finally, a **really** interesting planaria/BSG crossover: In 1939 R.H. Silber and V. Hamburger (Dr. Hamburger was one of developmental biology’s great minds) published a paper in the journal Physiological Zoology about planarian head regeneration (please see one of my previous posts for more details on planarian regeneration). Also, there is an absolutely awesome blog, “Regeneration in nature” that explores these concepts in more detail.

Anyway, under certain conditions, the worms were able to regenerate multiple heads in a specific configuration called duplicitas cruciata. Briefly, in this configuration two heads are oriented in opposite directions from each other, with two separate tails perpendicular to the heads. Below is a figure of a planaria expressing duplicitas cruciata side by side with a BSG raider:

Fasci . . . er. . . Really cool huh?

Isn’t science (and SF) wonderful?

If you want to know more

Brøndsted HV (1969) Planarian regeneration (International series of monographs in pure and applied biology. Division: Zoology). Pergamon Press; 1st edition.

Di Justo P and Grazier K (2010) The science of Battlestar Galactica. Wiley; 1st edition.

Silber RH and Hamburger V (1939) The production of duplicitas cruciata and multiple heads by regeneration in Euplanaria tigrina. Physiol Zool 12(3): 285-301.

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  1. Thank you! The story of this post is directly related to my scientific work. By now, it is pretty evident that I like SF (:-)… And I particularly loved the new BSG.

    I do not know if I have told you this, but I do research using planarians as an animal model in pharmacology/neurobiology. I was reading some older papers about it (the usual literature search) and as soon as I saw the pictures in the Silber & Hamburger paper, they immediately reminded me of the BSG raider!!!!! I even wondered if any of the creators or artists of the new series had a background in biology and maybe saw this paper…

    Yep, the brain is an incredibly complex structure, still poorly understood.



  2. I love the way you can associate flatworms with Battlestar Galactica… It’s a natural link that should be obvious to all 😉

    Seriously, I like the point about cutting up a planarian worm and then posing the question, which one is the original? I saw an interesting documentary that pointed out that neural activity occurs everywhere within the brain and not in just at one point or stemming from one control point, yet we think and live in a hierarchy (we’re in charge of our bodies) and yet there is no physical hierarchy or structure within the brain that matches that. The brain, it seems, is an example of synchronicity that culminates in a singularity, an individual. Planarians are physical, biological example of the same principle, especially those that resemble raiders 🙂


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