Wonderful Mysteries of Evolution

A guide for sci-fi authors and game designers down the rabbit hole of life

By MARTIN REZNY

While the basic science of the natural selection is quite clear and certainly not “just” a theory, there are many questions left unanswered. As a fan of science fiction, I’m sad to say that in regard to most of these, I’m still waiting for them to be pondered in speculative fiction, so consider this to be a letter to anyone who intends to write stories about alien life, courtesy of Dawkins and Tyson.

The Star Trek Problem

You know what it is, don’t you. Just think for a second, what’s the glaringly obvious issue with aliens on any given Star Trek show? It’s completely understandable from a practical standpoint, of course, but still, rather incompatible with the theory of evolution. All of the aliens not only have basically the same amounts of various bodyparts, they look exactly like us.

The differences are literally cosmetic, mainly for financial reasons. To the credit of the showrunners of TNG, this issue has been eventually addressed by an introduction of a common ancestor to all of the intelligent life in the galaxy, the Progenitor race. But even so, the diversity of lifeforms on Earth is already much greater than that of the whole galaxy of the Star Trek series.

My first advice therefore would be to look for inspiration down here. Did you know that octopi have distributed brains all over their body, so that they can control their multiple limbs, which is why those can move somewhat after cut off? Or about the many species that “see” via echolocation, in caves or seas? And did you know that mantis shrimp can punch with the force of a bullet?

Don’t get me started on mantis shrimp, it’s awesome. Its vision has up to 12 different photoreceptors, capable of recognizing even the polarization of light. Without any further explanation, it is not actually clear that our humanoid form is the best one even for a technological species, let alone for a monster, and our planet already shows just how much species can diverge.

On Evolutionary Convergence

With that said, it is not impossible that our universe is teeming with suspiciusly humanoid technological species, but there are a number of better and even more plausible explanations than a single galactic progenitor. Evolutionary convergence is a real phenomenon which sometimes occurs when species get isolated for a very long time, but evolve similarly.

The way one can conceptualize it on Earth is by counting how many times the same external trait has evolved completely independently. The creatures sharing that trait could have accomplished it in many different ways, and be completely different internally, but it’s still the same kind of way of dealing with the same kind of problem. It could be eyesight, speech, limbs, whatever.

If all of the alien spacefaring species looked very much like us, it would have to mean that there is some important benefit to being a bilateral, symmetrical, upright creature, with a big head hiding a big brain, and something like hands with crafty fingers. Or maybe it’s not the best form, but for some reason, the only smart and crafty one that can evolve, thus explaining the convergence.

By the way, did you know that there is a creature that evolved the ability to see through its own translucent skull? It has eyes on the inside. Anyway, another explanation for the galactic similarity could be that components of life are spread out all over the dust cloud in the galaxy, with the star systems around us taking about 250 million years to cycle through it periodically.

Possible Codes of Life

Which brings me to another as of yet unanswered question: is DNA the only kind of complex genetic molecule that can emerge? Already, there is a caveat to that because RNA, a different molecule, seems to have been the original one. With that said, it is not at all clear that life would have to be based on the same kind of molecule that we are, or that it would be the best molecule for it.

One possibility that was explored in some science fiction works was the possibility of life based on different chemistry altogether, centered around silicon, but that’s way less likely than a different genetic information carrier molecule based on carbon. Atom per atom, the most common atoms in us are the most common atoms of the universe in a strikingly similar distribution.

Just based on statistical reasoning, there is every chance that most of all life is carbon based. It doesn’t rule out the possibility of life based on silicon or ammonia, but again, statistically, most life should be made of most of the stuff available in the universe. One other feature of DNA was addressed in Mass Effect, a mirror image spiral fold of DNA, but that doesn’t really impact much.

And it is the possible impact of a difference that would make for a good sci-fi story in my opinion. Having a difference just to have a difference is kinda pointless. Maybe different chemistry would affect the availability of certain organic forms, or have them emerge in a different order. Maybe different chemistries of life can interact in dramatic ways. The possibilities are endless.

And yet, endlessly untapped. I suppose I’m in the disappointed Neil camp on this one. And this doesn’t even begin to tap into how different biology would translate into a different alien psychology, something that sci-fi so far also didn’t address very well, given that aliens are mostly stand-ins for humans. But that would require a whole other article, so, there’s an idea for next time.

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