The problem is that it isn’t how evolution works at all. I think this episode and the devolution one were probably the worst, science-wise. I mean, I know they play fast and loose with everything from basic physics to computer science, but for a biologist it’s kind of the equivalent of those stories that speculate that atoms are themselves tiny solar systems with the electrons as planets that have tiny civilizations on them.
They probably came up with the idea because computers using a pseudo-random number generator can produce the same series of “random” numbers if they start from the same seed. We know that evolution is a random process. Therefore, we should imagine that we could control evolution, even over the span of billions of years, if we control the seed. 
First, we have to define our terms. When I say “evolution,” I am referring to the phenomenon that describes the change in the genetic makeup of a population over time. When we talk about evolution more colloquially, we are usually referring to (to borrow a phrase) the origin of species by means of natural selection. In other words, it is the process that explains the diversity (and homogeneity) of life from genes through ecosystems to the biosphere. It takes place simultaneously at multiple levels and the number of non-pseudo random number generators (if we want to consider them that way) is incalculable.
One of the central principles of modern theoretical biology is that you can’t rewind the evolutionary tape. The further back you rewind it, the less like our present the outcome is likely to be. Wind it back far enough - say, to the very beginning at t=0, and not only do you not get humanoids, you’re not likely to get technological intelligence. I’d be surprised to see four-limbed animals or even vertebrates. The randomness comes in not just from things like the random genetic recombination that resulted in the randomly selected gametes that resulted in the individual in a process that traces itself back through the beginning of evolutionary time. It also affects which of the resulting organisms will survive, based in part on every other living thing that’s also undergoing those same processes.
The less random part is the fitness of an organism is the contribution of its generic material to the next generation. Picture two leopards, one faster than the other due to fortunate genetics. One has a 50% chance of propagating genes to the next generation, the other 25%. If the fastest leopard is a lucky mutant, there’s still a very good chance those genes will disappear. Over time, and given some lucky rolls of the dice, we’d expect the faster gene to spread, but it can be wiped out by an unfortunate event, like breaking a leg while hunting or an unfortunate fire or flood or a mutation that gives it cancer.
Sometimes we wind up at the same place from multiple routes. Eyes evolved independently somewhere around a couple dozen times. We can use that to say that sensing light is a pretty good idea. I would not be surprised if life on other planets evolved light sensing. I would expect the underlying mathematics of evolution to be the same, modulo whatever they use for reproduction.
The field of exobiology studies how we can abstract from our single example of a biosphere and our knowledge of evolutionary dynamics and apply it to try to conceive what non-terrestrial life is like. They ask questions like “What else could take the place of DNA?” and even more importantly “What is life?”
This one I can kinda let slide, as it’s really the only sensible explanation why aliens from across the galaxy all look alike, and maybe you can encode DNA with so many error correction mechanisms, that on similar M/L class planets it would give similar results. I mean… There are sillier explanations for sci-fi concepts.
Buuuuut Genesis (the de-evolution one), now that’s bad, and honestly for me it’s the worst ST episode in terms of concept. Threshold gets so much flak, but everything there we’ve seen before. And I’ll much rather believe humans can evolve into salamanders eventually than devolve into spiders just due to some radiation or whatever the reason was.
Genesis was worse, but they’re both so far off the rails that I really can’t let either one go. I’m a theoretical biologist, but I can watch ST and say “Oh, a sub space spore network? Cool! I hope he can make things work out with his doctor-boyfriend.” Paul Stamets, the Disco mycologist, is actually named after the real-life Paul Stamets, mycologist.
One of the things that I found really helpful to learn was that George Romero showed that you don’t need to tell them where zombies come from. Leave it up to the hard SF people to worry about what aliens might actually be like. It’s accepted in science fiction from Star Wars to the Roswell conspiracies that aliens are hominids. They might be squid-people or lizard-people, but aside from Douglas Adams and his hyperintelligent shade of blue, they all look like some kind of terrestrial life.
I’m just saying that if you’re playing a bit fast and loose with the science part of your science fiction, you’re better off with “This is a Klingon. The Klingon says ‘Grrrr!’”
You can get all interesting about the Changlings living in the ultimate retirement home of Lake Havasu (I might be getting mixed up - I just rewatched Falling Down), but that’s more social than biological and they don’t need to get more into it than that.
Well if you’re an expert in a field, then you necessarily have a problem with fiction unless it’s some ultra hard sci-fi. The whole concept of FTL travel is generally believed to be impossible for example, so imagine how the entirety of ST has to seem to an astrophysicist.
There’s always a line where “imagine if…” turns into “ok this is just a complete lie”, but the line is both fine and blurry, and somewhere else for everyone. I think the progenitors fall into the same category as warp drive - bonkers, but you can see where the general idea comes from, and with some headcanon or handwaving you can make it fit at least enough to work in a coherent universe.
At least I’m not a fan of letting too many fundamental concepts be “just roll with it”. Still waiting for explanations on how universal translators work that they make lipsyncing perfect, or a decent theory of artificial gravity.
But anyway. How would you explain why so many aliens look so similar? In-universe, obviously.
What I don’t know is why the universal translators don’t work when they want the Klingon to speak Klingon. I figured the lip-sync is from the neural interface link that works like a tiktok filter.
But that’s a good question. How could we explain the embarrassing excess of hominids in science fiction?
Okay - my argument as to why it’s ridiculous hinges on what we’ve seen in earth evolution. Four limbs evolved (we think) exactly once. Hominids once. Human intelligence once. Compare that to things like eyes, flying, swimming, tapered bodies, and so on. I expect, were we ever to find alien life, they might well have some of those properties.
But — What if the scarcity of intelligent hominids on earth was just an artifact, and in fact developing four limbs, running around, and eventually getting a hands and standing up was like eyes on almost every other planet? Our evolutionary history made it, via bad luck, that it only evolved once here. Across every other life-bearing planet, though, it’s as eyes? All of the planets’ ecosystems are teeming with monkey-like creatures. Lizard monkeys. Amphibian monkeys. Spider monkeys. Wait - scratch that last one. Anyway, I’ll leave the explaining why we don’t see all those monkey-aliens to someone else.
For my second opinion, I offer the following filk song:
(Tune: Yellow Rose of Texas )
Well, that glob of nose latex-is
The only way, you see
To keep down on the budget
On Ess Tee: Tee Enn Gee
We blew a million dollars
On starship flats and sets
So a small glob of latex-is
As good as the ail-yuns gets.
CHORUS:
She’s the sweetest little alien
That Starfleet ever knew
Her ears have rubber tips on
Held on with Elmer’s Glue
We’re tops at doing phaser shots
And spaceship warp effects
But the al-yuns’ look latex-is
With some wattles on their necks.
INSTRUMENTAL BREAK
So a wad of brown latex-is
On the brow of Mr. Worf
Anything more complicated
Make-up folks call it too torf
With a nose brow for Bajorans
Bulgy head for Fer-en-gi
A little wad of latex-is
The only thing we’ll see…
Our evolutionary history made it, via bad luck, that it only evolved once here.
Well we see on VOY that dinosaurs eventually evolve into that form too.
Hmmm I dunno. It’s an interesting thought, but somehow feels less believable, even contrived, especially in combination with needing humanoids for actors.
I mean, say we discover aliens irl, like lots of them. If they all look like humans, then I think a lot more people are rather gonna take it as a sign of intelligent design. While some others will say that Trek predicted it.
Um, claps for the song, but I can’t appreciate that properly. Best make a new post out of that.
The problem is that it isn’t how evolution works at all. I think this episode and the devolution one were probably the worst, science-wise. I mean, I know they play fast and loose with everything from basic physics to computer science, but for a biologist it’s kind of the equivalent of those stories that speculate that atoms are themselves tiny solar systems with the electrons as planets that have tiny civilizations on them.
They probably came up with the idea because computers using a pseudo-random number generator can produce the same series of “random” numbers if they start from the same seed. We know that evolution is a random process. Therefore, we should imagine that we could control evolution, even over the span of billions of years, if we control the seed. 
First, we have to define our terms. When I say “evolution,” I am referring to the phenomenon that describes the change in the genetic makeup of a population over time. When we talk about evolution more colloquially, we are usually referring to (to borrow a phrase) the origin of species by means of natural selection. In other words, it is the process that explains the diversity (and homogeneity) of life from genes through ecosystems to the biosphere. It takes place simultaneously at multiple levels and the number of non-pseudo random number generators (if we want to consider them that way) is incalculable.
One of the central principles of modern theoretical biology is that you can’t rewind the evolutionary tape. The further back you rewind it, the less like our present the outcome is likely to be. Wind it back far enough - say, to the very beginning at t=0, and not only do you not get humanoids, you’re not likely to get technological intelligence. I’d be surprised to see four-limbed animals or even vertebrates. The randomness comes in not just from things like the random genetic recombination that resulted in the randomly selected gametes that resulted in the individual in a process that traces itself back through the beginning of evolutionary time. It also affects which of the resulting organisms will survive, based in part on every other living thing that’s also undergoing those same processes.
The less random part is the fitness of an organism is the contribution of its generic material to the next generation. Picture two leopards, one faster than the other due to fortunate genetics. One has a 50% chance of propagating genes to the next generation, the other 25%. If the fastest leopard is a lucky mutant, there’s still a very good chance those genes will disappear. Over time, and given some lucky rolls of the dice, we’d expect the faster gene to spread, but it can be wiped out by an unfortunate event, like breaking a leg while hunting or an unfortunate fire or flood or a mutation that gives it cancer.
Sometimes we wind up at the same place from multiple routes. Eyes evolved independently somewhere around a couple dozen times. We can use that to say that sensing light is a pretty good idea. I would not be surprised if life on other planets evolved light sensing. I would expect the underlying mathematics of evolution to be the same, modulo whatever they use for reproduction.
The field of exobiology studies how we can abstract from our single example of a biosphere and our knowledge of evolutionary dynamics and apply it to try to conceive what non-terrestrial life is like. They ask questions like “What else could take the place of DNA?” and even more importantly “What is life?”
Sorry for the rant.
Sir, this is a Risa’s drive-through.
This one I can kinda let slide, as it’s really the only sensible explanation why aliens from across the galaxy all look alike, and maybe you can encode DNA with so many error correction mechanisms, that on similar M/L class planets it would give similar results. I mean… There are sillier explanations for sci-fi concepts.
Buuuuut Genesis (the de-evolution one), now that’s bad, and honestly for me it’s the worst ST episode in terms of concept. Threshold gets so much flak, but everything there we’ve seen before. And I’ll much rather believe humans can evolve into salamanders eventually than devolve into spiders just due to some radiation or whatever the reason was.
Genesis was worse, but they’re both so far off the rails that I really can’t let either one go. I’m a theoretical biologist, but I can watch ST and say “Oh, a sub space spore network? Cool! I hope he can make things work out with his doctor-boyfriend.” Paul Stamets, the Disco mycologist, is actually named after the real-life Paul Stamets, mycologist.
One of the things that I found really helpful to learn was that George Romero showed that you don’t need to tell them where zombies come from. Leave it up to the hard SF people to worry about what aliens might actually be like. It’s accepted in science fiction from Star Wars to the Roswell conspiracies that aliens are hominids. They might be squid-people or lizard-people, but aside from Douglas Adams and his hyperintelligent shade of blue, they all look like some kind of terrestrial life.
I’m just saying that if you’re playing a bit fast and loose with the science part of your science fiction, you’re better off with “This is a Klingon. The Klingon says ‘Grrrr!’”
You can get all interesting about the Changlings living in the ultimate retirement home of Lake Havasu (I might be getting mixed up - I just rewatched Falling Down), but that’s more social than biological and they don’t need to get more into it than that.
Well if you’re an expert in a field, then you necessarily have a problem with fiction unless it’s some ultra hard sci-fi. The whole concept of FTL travel is generally believed to be impossible for example, so imagine how the entirety of ST has to seem to an astrophysicist.
There’s always a line where “imagine if…” turns into “ok this is just a complete lie”, but the line is both fine and blurry, and somewhere else for everyone. I think the progenitors fall into the same category as warp drive - bonkers, but you can see where the general idea comes from, and with some headcanon or handwaving you can make it fit at least enough to work in a coherent universe.
At least I’m not a fan of letting too many fundamental concepts be “just roll with it”. Still waiting for explanations on how universal translators work that they make lipsyncing perfect, or a decent theory of artificial gravity.
But anyway. How would you explain why so many aliens look so similar? In-universe, obviously.
What I don’t know is why the universal translators don’t work when they want the Klingon to speak Klingon. I figured the lip-sync is from the neural interface link that works like a tiktok filter.
But that’s a good question. How could we explain the embarrassing excess of hominids in science fiction?
Okay - my argument as to why it’s ridiculous hinges on what we’ve seen in earth evolution. Four limbs evolved (we think) exactly once. Hominids once. Human intelligence once. Compare that to things like eyes, flying, swimming, tapered bodies, and so on. I expect, were we ever to find alien life, they might well have some of those properties.
But — What if the scarcity of intelligent hominids on earth was just an artifact, and in fact developing four limbs, running around, and eventually getting a hands and standing up was like eyes on almost every other planet? Our evolutionary history made it, via bad luck, that it only evolved once here. Across every other life-bearing planet, though, it’s as eyes? All of the planets’ ecosystems are teeming with monkey-like creatures. Lizard monkeys. Amphibian monkeys. Spider monkeys. Wait - scratch that last one. Anyway, I’ll leave the explaining why we don’t see all those monkey-aliens to someone else.
For my second opinion, I offer the following filk song:
(Tune: Yellow Rose of Texas )
Well, that glob of nose latex-is The only way, you see To keep down on the budget On Ess Tee: Tee Enn Gee
We blew a million dollars On starship flats and sets So a small glob of latex-is As good as the ail-yuns gets.
CHORUS:
She’s the sweetest little alien That Starfleet ever knew Her ears have rubber tips on Held on with Elmer’s Glue
We’re tops at doing phaser shots And spaceship warp effects But the al-yuns’ look latex-is With some wattles on their necks.
INSTRUMENTAL BREAK
So a wad of brown latex-is On the brow of Mr. Worf Anything more complicated Make-up folks call it too torf
With a nose brow for Bajorans Bulgy head for Fer-en-gi A little wad of latex-is The only thing we’ll see…
Well we see on VOY that dinosaurs eventually evolve into that form too.
Hmmm I dunno. It’s an interesting thought, but somehow feels less believable, even contrived, especially in combination with needing humanoids for actors.
I mean, say we discover aliens irl, like lots of them. If they all look like humans, then I think a lot more people are rather gonna take it as a sign of intelligent design. While some others will say that Trek predicted it.
Um, claps for the song, but I can’t appreciate that properly. Best make a new post out of that.
The evolutionary predestination thing used to justify following the Prime Directive before it was a thing in ENT is also pretty awful.
Excellent rant! 10/10, please rant more! Thoroughly enjoyable, and educational!