Attempting to Cross Breed H. Sapiens and H. Kryptoniens

[Broomstick]

I've been re-visiting the Superman universe of late, watching the various movies, TV shows, reading the comic books and graphic novels... “only” three quarters of a century of mythos (plus continuity snarls) to explore. Why? I dunno. Doesn't really matter I suppose.

Anyhow – one of the things that comes up periodically is Clark/Superman/Kal-El getting it on with Lois Lane (or other human female, like Lana Lang). Now, there are two outcomes to this down the road. Either it is possible for offspring to happen, or it isn't.

So.... read the poll and vote. You may base your answer on logic, preference, or a coin toss. Your choice.

Personally, I'm in the “you can't cross Kryptonian and Human” camp but I'm curious to see where everyone else is.

[Simon_Jester]

Virtually every time the issue has come up in the comics, it's been possible for Superman to have children with humans. There may be exceptions, I don't know. Is this plausible? Well, arguably not, but if we actually think through the question "why can Superman interbreed with humans," we have a ton of related questions like "why can he even eat human food and receive nutritional benefit from it?"

And Superman isn't even the only character in the DC comics universe who's got a relationship going with a being from another planet and has (or could have) had children with them. Face it, somehow a lot of the aliens in DC comics are just 'space humans-' beings with cosmetic differences that are no more significant for reproductive purposes than the difference between, oh, Siberians and Australian Aborigines.

[Borgholio]

Oddly, the first thing that ever came to mind when I thought about this was not genetics. It was the physical aspect. In other words...unless he has practiced great control over it...couldn't the act of ejaculation blow her head off from the inside due to the force of it?

[Broomstick]

Virtually every time the issue has come up in the comics, it's been possible for Superman to have children with humans. There may be exceptions, I don't know. Is this plausible? Well, arguably not, but if we actually think through the question "why can Superman interbreed with humans," we have a ton of related questions like "why can he even eat human food and receive nutritional benefit from it?"

I can eat and derive nutritional benefit from food items I can't reproduce with, so that doesn't strike me as being quite so whack.

If you consider that Kryton is/was sufficiently different from Earth that, by our standards, it's arguably a hellworld (characteristics have included things like a gravity 15 times that of Earth, just for starters) it does leave the question of how the hell CK can be compatible enough with Earth life to get anything out of eating. The answers, of course, are varied: same reason he can crossbreed with a Human (because the writer said so); all life in the universe uses similar chemicals (ok... somewhat plausible and not currently disproved by science); he doesn't get any nutritional benefit because he's solar powered; wave hands and mumble.

The whole can he or can't he reproduce with Humans is pretty inconsistent across all media. Yes, in the comics/graphic novels he usually seems able to have kids (usually with Lois) and some stories involved future descendants (implying he reproduced with someone, though name and species is not always specified), but if I recall the story line with Christopher Kent/Lor-Zod had CK and Lois married but not able to have children of their own. Superman Returns had a Superkid. Lois and Clark fell into the unable to cross species category although several episodes involving a time travel from the future had the world run by the descendants of CK and Lois implying they somehow overcame the biological barrier involved (I'm guessing magiteck of some sort) but the series ended before that was ever addressed (which might be a good thing).

Well, hell, DC has happily spun off alternate universes, what-ifs, aborted time lines, and Og knows what else over the decades. Basically, they've explored all four options at one point or another.

I don't know why I prefer "no crossbreeding" in an already fantastical story universe, I just do. I am perfectly happy to let others have their preferences, though.

Oddly, the first thing that ever came to mind when I thought about this was not genetics. It was the physical aspect. In other words...unless he has practiced great control over it...couldn't the act of ejaculation blow her head off from the inside due to the force of it?

If you haven't read it already I strongly recommend "Man of Steel, Woman of Kleenex" by Larry Niven, which not only addresses your concerns but is also hilarious.

"Don't hurt the girl" has also been addressed multiple times, from "CK has incredible control" to "depower him before he deflowers her".

I also recommend the "World of Cardboard" speech (Supes gets going around 0:45 on that link) because the whole "how does Superman exist in the world without leaving a trail of utter destruction in his wake?" has been asked many times, and it always seems to come down to inhuman control over himself.

[mr friendly guy]

Oddly, the first thing that ever came to mind when I thought about this was not genetics. It was the physical aspect. In other words...unless he has practiced great control over it...couldn't the act of ejaculation blow her head off from the inside due to the force of it?

Red sunlight buddy. Red sunlight.

[Broomstick]

Right. "Depower before deflower".

[Borgholio]

Thank you, Broomstick. That article made me laugh my ass off.

One sperm arrives before the others. It penetrates the egg, forms a lump on it's surface, the cell wall now thickens to prevent other sperm From entering. Within the now-fertilized egg, changes take place...

And ten million Kryptonian sperm arrive slightly late.

Were they human sperm, they would be out of luck. But these tiny blind things are more powerful than a locomotive. A thickened cell wall won't stop them. They will all enter the egg, obliterating it entirely in an orgy of microscopic gang rape. So much for artificial insemination.

[Broomstick]

I first read that article 40 years ago. It still makes me laugh.

[Zixinus]

There is no logical reason why Clark should even look human, never-mind have no problem being on earth or even reproduce with humans.

But because everyone views even the most basic of biology with contempt and as something that imposes useless rules that makes any story boring ("like, an alien would have to wear a suit all the time and couldn't eat burgers! How are you supposed to laugh at how aliens like burgers if they have to wear a suit all the time?"), so of course Superman will have children. Almost all comic book and TV aliens are just really humans with funny foreheads or something. They by all reason should be as compatible with Earth's biosphere as humans are to Jupiter, but then writers would actually have to consider their aliens more than just "freaky people from space!".

Though, wasn't Superman originally written as a human, just from the future (and superman was superhuman in every way for some reason)? Then it would make some sense.

[Broomstick]

So far as I can tell no, he has always been the orphan from space. There were a few prototype characters before the Action Comics #1, and Schuster and Siegel didn't delve into his origins for at least a couple stories at first but the idea of him being the ultimate immigrant was there from the start.

The resemblance between Humans and Kryptonians has been explained for a couple decades as "convergent evolution" which can result in some strong resemblances. However, it doesn't give identical results and CK should still look "off" in some respects. On top of that, with Krypton being such a wildly different environment than Earth there actually shouldn't be all that much convergence. OK, explanation patch #2 is that Jor-El searched galaxies worth of star systems to find one where an improbable level of convergence happened despite a vastly different environment.

Really, the notion of a progenitor race seeding star systems with proto-humanoids starts to make more sense than that.

You do get storylines where, despite superficial appearances, CK shows marked differences from Humans. Apparently under a simple microscope there are easily distinguished celluar differences. Sometimes writers make mention of different heart rate or the like (when they're not allowing him to control it minutely through superbiofeedback or whatever).

But yeah, if you're wondering how he eats and breathes / And other science facts / Then repeat to yourself 'It's just a show comic book, / I should really just relax..

[Simon_Jester]

Virtually every time the issue has come up in the comics, it's been possible for Superman to have children with humans. There may be exceptions, I don't know. Is this plausible? Well, arguably not, but if we actually think through the question "why can Superman interbreed with humans," we have a ton of related questions like "why can he even eat human food and receive nutritional benefit from it?"

I can eat and derive nutritional benefit from food items I can't reproduce with, so that doesn't strike me as being quite so whack.

Yes, but those food items are still part of a biochemical schema that you evolved to eat and that is on a basic level compatible with your own biochemical makeup. The things you eat are made of the same kind of DNA base pairs, produce many of the same vitamins, rely on the same kind of trace elements as you do, and as much to the point do NOT rely biochemically on substances poisonous to you.

When we open this particular can of worms... well, there's no reason to assume that Kryptonian life wouldn't evolve use, say, arsenic as a vital trace mineral, while being badly poisoned by, say, phosphorus... which is present in all Terrestrial life. Or any of a thousand other possibilities if you can think of a reason to dismiss that one.

I mean, we normally wouldn't take for granted that a baby launched to an alien planet would even find anything to eat, even if the local aliens were sincerely trying to take care of it as best they could. And yet this is precisely what happened to Superman with the Kents.

If you consider that Kryton is/was sufficiently different from Earth that, by our standards, it's arguably a hellworld (characteristics have included things like a gravity 15 times that of Earth, just for starters) it does leave the question of how the hell CK can be compatible enough with Earth life to get anything out of eating. The answers, of course, are varied: same reason he can crossbreed with a Human (because the writer said so); all life in the universe uses similar chemicals (ok... somewhat plausible and not currently disproved by science); he doesn't get any nutritional benefit because he's solar powered; wave hands and mumble.

We can assume Superman is solar-powered and has been since infancy, but I've never yet seen evidence that he can survive and thrive indefinitely on sunlight alone. Also, did his parents know he 'eats' sunlight, if that is true? If so or if not, what kind of consequences would that have?

The whole can he or can't he reproduce with Humans is pretty inconsistent across all media. Yes, in the comics/graphic novels he usually seems able to have kids (usually with Lois) and some stories involved future descendants (implying he reproduced with someone, though name and species is not always specified), but if I recall the story line with Christopher Kent/Lor-Zod had CK and Lois married but not able to have children of their own. Superman Returns had a Superkid. Lois and Clark fell into the unable to cross species category although several episodes involving a time travel from the future had the world run by the descendants of CK and Lois implying they somehow overcame the biological barrier involved (I'm guessing magiteck of some sort) but the series ended before that was ever addressed (which might be a good thing).

Well, hell, DC has happily spun off alternate universes, what-ifs, aborted time lines, and Og knows what else over the decades. Basically, they've explored all four options at one point or another.

I don't know why I prefer "no crossbreeding" in an already fantastical story universe, I just do. I am perfectly happy to let others have their preferences, though.

As for myself, I do not much care either way. My point is simply that IF you want to make a major point of the issue, you have basically forced yourself to address other issues that are if anything more annoying and problematic. Superman being functionally a sterile dead-end because he's the last of his species (discounting Supergirl or bottled cities or whatever) is much less of a problem for his character than Superman suffering nutritional deficiencies because his parents didn't know he needs arsenic salts to grow healthy bones in infancy.

Oddly, the first thing that ever came to mind when I thought about this was not genetics. It was the physical aspect. In other words...unless he has practiced great control over it...couldn't the act of ejaculation blow her head off from the inside due to the force of it?

If you haven't read it already I strongly recommend "Man of Steel, Woman of Kleenex" by Larry Niven, which not only addresses your concerns but is also hilarious.

"Don't hurt the girl" has also been addressed multiple times, from "CK has incredible control" to "depower him before he deflowers her".

I also recommend the "World of Cardboard" speech (Supes gets going around 0:45 on that link) because the whole "how does Superman exist in the world without leaving a trail of utter destruction in his wake?" has been asked many times, and it always seems to come down to inhuman control over himself.

[Pictures a very different take on the World of Cardboard speech in the context of Superman getting into a relationship with some superpowered woman with whom he doesn't need that level of control...]

The resemblance between Humans and Kryptonians has been explained for a couple decades as "convergent evolution" which can result in some strong resemblances. However, it doesn't give identical results and CK should still look "off" in some respects. On top of that, with Krypton being such a wildly different environment than Earth there actually shouldn't be all that much convergence. OK, explanation patch #2 is that Jor-El searched galaxies worth of star systems to find one where an improbable level of convergence happened despite a vastly different environment.

Really, the notion of a progenitor race seeding star systems with proto-humanoids starts to make more sense than that.

Well, clearly Jor-El had some idea that Earth would be a place where Kryptonians could actually live and survive, right? Although I suppose that might also vary between takes on his character, but really it would be very irresponsible to just fire your only child off into space to a random planet where they might be killed instantly by exposure to the atmosphere or something.

Anyway.

The 'progenitor' theory is also pretty compelling, honestly. And since Kryptonians are FAR from the only alien species in the DC Universe that look basically identical to humans with only slight cosmetic differences, it becomes all the more believable.

[Darth Nostril]

[Batman]

Given the absurdity of Clark doing the stuff he does on solar power I never was particularly bothered by the fact that he looks entirely human or worried overmuch about whether or not he can breed with humans. It's superhero comics. People can move FTL because they were in the lab when lightning struck and set their chemicals on fire. Reproductive compatibility is small fry in context.

[TimothyC]

[Pictures a very different take on the World of Cardboard speech in the context of Superman getting into a relationship with some superpowered woman with whom he doesn't need that level of control...]

This was covered in an episode of Smallville. Lois got superpowered, and there were a whole lot of earthquakes afterwards.

There is also this comic that sums it up well.

As for H.sapiens and H. kryptoniens, we know that in the main continuity H. sapiens (specifically, a Mayan soldier) can impregnate an H. daxamiens (specifically Bal Gand, an ancestor of Lar Gand AKA Mon-El). Daxamites are functionally identical (pre genetic manipulation anyway - and this took place after Bal got pregnant) to Kryptonians so it would seem that it goes at least one way, and that the offspring are fertile.

[Broomstick]

Having a male Human impregnate a female Daxamite or Kryptonian would eliminate a lot of the "Man of Steel, Woman of Kleenex" issues, even leaving aside whether or not the two are inter-fertile.

[Terralthra]

If we assume that Kryptonian sperm are uber-sperm and annihilate a Terran egg wall's protective thickening, surely the converse is true, and a Terran sperm would bounce off of a pre-fertilization Kryptonian egg like firing boiled eggs at a brick wall.

[Zixinus]

But yeah, if you're wondering how he eats and breathes / And other science facts / Then repeat to yourself 'It's just a show comic book, / I should really just relax..

I don't read the comics and I don't get really riled up. It's just annoying that these sort of reasonable questions are always just dismissed away with hand-waving whenever it could come up.

If I would have written the story, I'd go with a simple solution: Kryptonians are wildly different creatures in terms of energy-chemistry and actually look very different from humans. But Superman's father could create a impregnable outer-body for his son. It would essentially act as symbiont: it would allow Superman to survive on Earth and appear human in almost every way. It would still require human food and Earth chemicals to grow. It would also be partially a brain that would encourage the Kryptonite-side of Clark to mimic human neural patterns, instincts and such. However, once Clark has sufficiently matured, his Kryptonian powers will be channeled through the symbiote, allowing him access to his Kryptonian abilities and powers. Once this happens the symbiote would be powered by Clark's Kryptonite biology and thus allows him to walk on the moon and such with only minor discomfort. His Kryptonite biology would also give him immunity to all or most diseases (except perhaps for those specifically targeting the symbiote) as the symbiote acts as a barrier while being too alien to be damageable by local microlife. The price of this is that Clark is forever stuck having this symbiont and is inseparable from it.

Thing was a successfully-prototyped, secret but abandoned project because the Kryptonians never really thought they'd need to leave their planet. Only Clark's Kryptonian-father had both access to this and foresight to use it in time. The thing does not work on adults, only on babies, which is another reason why it was abandoned. There were adult versions of these that could sort-of be worn like body-suit, but could not be stored long-term or Clark's father could not find them in time. Also, the symbiote only works on Earth and makes him stuck there until Clark's Kryptonite powers mature. Earth is picked because at the time of Kryptonite's last visit it was considered an ideal blend of resource-rich, pretty, safe, habitable (adult Kryptonians CAN walk around on it naked with impunity if necessary for up to months but would be miserable experience) and a good jumping-off point for krypto-forming other planets in the solar system (which was the real goal, Earth was meant to be just have a base). It was also a distant planet from Krypton's enemies and one they wouldn't look at, while still unclaimed.

The symbiont would able to make a sperm-substitute but that by itself just produce human offspring. The DNA of the baby is a derivative to the human Clark looks to be (the DNA was taken when Kryptonites visited Earth thousands of years ago and altered to fit into modern are). However, Clark's Kryptonian-father left behind blueprints and seed-material for Clark to allow the creation of further Kryptonite-human babies that can mature in a human female womb (perhaps with occasional injections into the developing Kryptonite-fetus of things that it would get in a Kryptonite-womb-analog). Resulting baby will have a similar Kryptonite-symbiote relationship as Clark had when he arrived on Earth, ie a normal baby that will blend in as a human until the child's Kryptonite biology matures enough to be able to protect itself. This point is actually artificial somewhat and can be triggered artificially if necessary (which might happen with certain medical complications).

There. An explanation on how an alien could live on Earth, look like a human and act like a human. It would even give with a little extra drama the possibility of normal reproduction and superbaby-reproduction if necessary for the plot. It might also humanize Clark in a way that he has vulnerabilities. It still assumes that Kryptonians are half-god beings but that is a given and partially the point with Superman anyway. If other Kryptonian shows up they have an excuse to look human: they too would have symbiotes of one nature or another. Superkids could be around too.
It would also give justification for Clark to have resources to make his Fortress of solitude: his pod was not meant to be a baby-carrier but actually a robot probe that would help set up basic aspects of the colony-base. The idea was to send one in a selected location and that would build an empty base that Kryptonian colonists could later customize. It was modified to be a baby-carrier later.

It's probably hideously complicated by comic-book standards, have several logic holes I can't see and probably be anathema to Superman-fans for some reason, but it would at least try to address the basic questions.

[Solauren]

It's also entirely possible that in the DC universe, one of the keys to both the humanoid form and sentience is a fixed number of chromosomes. In other words, part of evolution to a humanoid form and sentience is to end up with 46 chromosomes.

As a result, all humanoid sentient species in the DC Universe may be genetically compatible.

[mr friendly guy]

We can assume Superman is solar-powered and has been since infancy, but I've never yet seen evidence that he can survive and thrive indefinitely on sunlight alone. Also, did his parents know he 'eats' sunlight, if that is true? If so or if not, what kind of consequences would that have?

DC 1 million. He apparently is still alive in the 853rd century having stayed in the sun for IIRC thousands of years.

[biostem]

I've always thought it odd that Superman can still enjoy a soft touch from someone he loves, like Lois Lane, while also withstanding a punch from Doomsday. It's a tremendous range of sensitivity vs insensitivity, IMO.

Regardless, this is comic book physics we're talking about here - at least Quicksilver had to brace Magneto's head before running off w/ him in DoFP. If Supes were to do a hyperspeed catch of someone falling, cradling them in his arms wouldn't be enough to protect against the kind of acceleration and change in direction they just experienced.

I suppose a temporary depowering via Red Sunlight radiation would be the safest bet.

[Broomstick]

There's the notion that Superman has some sort of protective aura, which both accounts for why his clothes (usually) don't disintegrate into nothing, and it somehow extends to protecting people he catches from sudden deceleration, or people he runs/flies with from the effects of speed-induced friction with the air.

If you claim that, then presumably it would protect a Human he was having sex with.

[Iroscato]

Just read the article. The part where the super-sperm go on a rampage across Metropolis fucking killed me.

[Batman]

Curiously enough, 'Superman-The Movie' of all sources provides an out for how Clark manages to catch people without killing them-he visibly dips several meters after catching Lois dropping from the helicopter, allowing for him to 'softly' decelerate her fall.
Him coming in at Warp 9 doesn't matter if he 'stops' immediately before the catch and does something similar.

[Borgholio]

There's the notion that Superman has some sort of protective aura,

Actually in the original 1978 Superman movie, this is demonstrated when Superman grants Lois the power of flight just by touching fingertips. Skip to 0:40.

[Batman]

Tactile telekinesis (a self-defeating term if I ever heard one). Hey, it worked for Conner.
Besides, movie Clark could turn back time by making Earth rotate in the opposite direction.