[Aliens] [Bio-Tech] Cross-species gestation as a reproductive strategy?

[vicky_molokh]

Greetings, all!

I'm trying to develop one of the ideas from this as part of the major remake of Æthereal Sun (new name pending). I'm aiming for moderate-high weirdness, but at least a semblance of plausibility, so I'm trying to keep the idea strange enough while making sure it doesn't break suspension of disbelief completely:

A species that evolved under symbiotic conditions among other humanoid species/races, such that it never gestates its own young. The idea is that their gametes are compatible with, or adaptable to, the uteral endometrium, and the immune system in general, of the host races/species.

If it matters, I think it would be more interesting if Sirkin were naturally chimeric and/or mosaic, such that multiple gametes in the same group could possess different genetic content, and yet develop into a single individual with no problem. This is not a trait I'm hard-set on keeping, but it's kinda interesting. *shrug*

So far, you're probably imagining some sort of Incubus race . . . But! Please don't. They're supposed to be relatively likeable.

Now, the hard part is that I still want them to maintain two distinct anatomical and superficial physiological (though not necessarily complete physiological!) sexes, and possibly two or more genders too. Yes, that's right, parthenogenesis is perfectly acceptable, or some mechanism of mixing genes - perhaps some sort of exchange where genetic sex doesn't really matter. I also would prefer to keep away from hermaphromorphs, as that is too cliché (already the replies seem to imply people see them as Kirk-like James Bonds in terms of intimate lives).

Now, the evolutionary use of an anatomical/superficial physiological male sex and a more-or-less male gender (social) for such a species is obvious. But what about the anatomical female?
Some ideas for the anatomical females that I would like to hear comments on:

• Used for exchange of genetic data within the species. Kinda rises the question of how practical it is to transfer data (most likely carried by specialized cells) from a female to a male while having at least externally human genitalia of both anatomical sexes. Makes one think of mechanisms used by STDs, actually (i.e. specialized cells or virus-like constructs that must get through the mucous membrane of the anatomical male's genitals), which seems weird.
• And/or: Not only can they transfer genetic data onto males using specialized cells or virus-like constructs, but said cells/virus-like constructs can also (temporarily or permanently) 'take over' a male non-Sirkin's reproductive system, resulting in production of Sirkin gametes (either exclusively and constantly, periodically, or just a certain percentage). I'm pretty sure Mark Skarr had that sorta character somewhere.
  The big problem is that if it is permanent, such a mechanism will likely be too effective if it works at all and (2) make the species gets into lots of trouble once scientists discover the mechanism (I think this should happen by early TL7 if not earlier). The idea of a single 'encounter' with a Sirkin being able to dictate who your children will be does have a dark-humour sort of appeal, but it's not what I'm aiming for.
  If it is temporary, stuff won't get that bad. However, it means that evolutionarily, Sirkin 'females' are interested in non-Sirkin practicing either polygamy, or very fast serial monogamy. And then there's the problem with justifying the temporary-ness of the mechanism.
  Edit: If it's permanent but either periodic or percentile (as in, there's just some chance of the non-Sirkin male begetting a Sirkin child after that), then it's probably also not as nasty.
  If any variant of this option is true, this immediately rises a question whether the less likely event of these 'commando' cells/constructs reaching a female mucous membrane would also enable a takeover. From an evolutionary PoV, it is probably rather advantageous in cases when this is an option, but might be too rare for the evolutionary pressure to exist for such an adaptation (i.e. I have no idea whether the adaptation is worth the payoff).
• Alternately: They either are either a current or vestigal caste that mostly focuses on a different function, and has a non-neuter sex and behaviour merely for avoiding suspicion from other species, as a masking mechanism. This likely means that Sirkin anatomical females are actually sterile, like worker bees.
• They actually gather genetic material from other species and/or use other species' genes to randomize their own genetic code. This is probably waaaay over the top in terms of weirdness, and quite into fantasy territory. Or is it?
• Anything I didn't think of, which you are welcome to add. :)

The racial template is under consideration, but here are some traits that I would prefer to include:

• Mild Xenophilia for obvious reasons.
• Some set of: Honest Face, Appearance, Pitiable, Sanitized Metabolism, both to improve their chances with the symbiotic species, as well as to prevent abandonment of 'alien' children (though I guess their kids are not very distinctive compared to other races). Most likely, Sanitized Metabolism alone would be enough to become the favourite kid in the family from the earliest days. I suppose some Sirkin may lose SanMet and Pitiable by adulthood, but not necessarily.
• Skinny and/or low HT to denote their ability to rely on another species for the more physical tasks. Narrower hips too, I guess.
• Oblivious and a low-key set of IQ-oriented advantages to denote the somewhat passive social strategy combined with the weakened family bonding and near-absent maternal/paternal instincts. This group of traits could as well be an evolutionary 'accident'. I really oppose the idea of making them social monsters. An interesting point would be that since anatomical males are more likely to have a family with children, they're the ones that likely have a more human-level paternal instinct, while anatomical females are likely more careless.

Thanks in advance!

[Lamech]

First any genetic sharing of info won't cross over to aliens from other planets*. I think you have this down, but just to be sure.

A species that evolved under symbiotic conditions among other humanoid species/races, such that it never gestates its own young. The idea is that their gametes are compatible with, or adaptable to, the uteral endometrium, and the immune system in general, of the host races/species.

Generally the developing fetus is protected somewhat from the mother's immune system. When infecting another race it would need to effectively mimic whatever the target embryo "looks" like. Trigger the same receptors ect.
Note: this assumes reproductive/immune systems similar to the ones on earth.

If it matters, I think it would be more interesting if Sirkin were naturally chimeric and/or mosaic, such that multiple gametes in the same group could possess different genetic content, and yet develop into a single individual with no problem.

If this is what I think you want, it would mean part of the combined baby, has DNA from the Sirkin incubus, and other cells have the DNA of the host? That would be interesting.

But the hard part is that I still want them to maintain two distinct anatomical and superficial physiological (though not necessarily complete physiological!) sexes, and possibly two or more genders too. Yes, that's right, parthenogenesis is perfectly acceptable, or some other mechanism of mixing genes - perhaps some sort of exchange. I also would prefer to keep away from hermaphromorphs, as that is too cliché.

Parthogenesis doesn't really work with two genders. It could totally have worker drones, or whatever, but parthogenesis creates clones, which kind of kills the concept of "gender".

So one idea for the "mechanics" of it all. Two incubi (one of each gender) exchange DNA, and create an Incubus egg, and then said egg gets implanted in a host. Which going with the incubus theme means the females would look like a male: from this point forward, I'm referring to the female as the one that actually "implants" the egg.

On the traits they would need; the males need xenophilia since they need to be a go between the females; each female mimics one race (barring shapeshifting) so unless the males act a go between the species will break up into several ones. Two while familial bonds don't exist the whole species sounds like it might be very conspiratorial, which would create a very interesting kind of bond.

I also note that the children of the Incubi will probably evolve to be manipulative to get as much in the way of resources as possible. Possibly have some method of faking sickness or whatever. They lack the pressure of kin-selection, that otherwise prevents this. On a final note if its a chimera most things don't need to be replaced. Some changes to the brain to increase social/manipulating skills, the reproductive system, and some way to identify each other; finally any better adaptions that they have evolved will be in the final incubus.

*More precisely that evolved independently. If nano-bots controlled the evolutionary paths of species on different planets or whatever all bets are off.

[Bruno]

Transferring gametes to the "Male" already has a precedent, see seahorses. He could hold the female eggs unfertilized until he finds an opportunity to um "infect"? a host.

It sounds a bit like Larry Niven's Puppeteers - they had a strict symbiotic relationship with one (nonsentient) species though, and the breeding process might have been fatal to the host species. It probably still counts as symbiotic though, as the nonsentient host species gets the full benefit of being cared for by a technological civilization.

[sir_pudding]

Originally Posted by Bruno

It probably still counts as symbiotic though, as the nonsentient host species gets the full benefit of being cared for by a technological civilization.

It does regardless, parasitism is a form of symbiosis.

[Genesis]

What a great idea...

I see no biological reason for an alien race not to have evolved a mechanism where each individual (or even cell) possesses inherited genes from more than two individuals in the parent generation. There are all sorts of natural mechanisms that deal with varying gene copy number, and even use it to do interesting things phenotypically.

I furthermore suggest that the females aren't a problem either. Sirkin gametes must still combine with Sirkin gametes to produce children. Perhaps there's a minimum number of parents, without which a functioning fetus cannot grown! Perhaps the males and females don't carry the same genes, and proto Sirkin don't become viable until they've got copies from each sex!

If this last is the case, consider that the distribution of children from a male and female Sirkin would look very different. A female Sirkin might leave a limited stock of viable gametes with a male, which will may quickly exhaust themselves if they lack the means to reproduce (for the sake of stealth it seems only wise for this to be the case). These gametes then have to find their way to the uterus of a host female who has also interacted directly with a male of the Sirkin species. The two genders might have "transitive sex" with the potential host. If this was the case, females might "father" multiple Sirkin children with a single sexual act, while males would require a different act, with a different host, for each offspring. Depending on the proportions in the species this could make things interesting....

Even if you don't need genes from both sexes to form a viable offspring, Sirkin would still "prey" primarily on the sluttiest people and races possible. It would be in a female Sirkin's best interest to seduce the most promiscuous human males around (which introduces a great "prey on the predator" potential dynamic...), while males might actively seek out the recent human partners of such "studs" and compete to bed them while the female gametes (with their valuable genes) are still viable.

Actually, this is a great race. I'm totally making a Lovecraftian-style horror race that does exactly this for my current game...

[Purple Haze]

http://www.wired.com/wiredscience/2011/05/clam-cloning/

[vicky_molokh]

Originally Posted by Lamech

Note: this assumes reproductive/immune systems similar to the ones on earth.

Yes.

Originally Posted by Lamech

If this is what I think you want, it would mean part of the combined baby, has DNA from the Sirkin incubus, and other cells have the DNA of the host? That would be interesting.

It would be cool, but I'm afraid to stretch SoD too far.

Originally Posted by Lamech

Parthogenesis doesn't really work with two genders. It could totally have worker drones, or whatever, but parthogenesis creates clones, which kind of kills the concept of "gender".

Why not? It occurs in some lizards, who have male stand-ins and female stand-ins in the act of mating (though the evolutionary usefulness of that is unclear), and then the genders are switched in another mating. All this while the whole species only has one sex. They don't produce perfect clones in the strict definition either.

Originally Posted by Lamech

So one idea for the "mechanics" of it all. Two incubi (one of each gender) exchange DNA, and create an Incubus egg, and then said egg gets implanted in a host. Which going with the incubus theme means the females would look like a male: from this point forward, I'm referring to the female as the one that actually "implants" the egg.

Yeah, whether the genetic or anatomical sex is referred to can be an interesting way to a mind-screw for the players (and the less biologically inclined characters too).

Originally Posted by Lamech

On the traits they would need; the males need xenophilia since they need to be a go between the females; each female mimics one race (barring shapeshifting) so unless the males act a go between the species will break up into several ones. Two while familial bonds don't exist the whole species sounds like it might be very conspiratorial, which would create a very interesting kind of bond.

I'm not sure I understand the whole paragraph.

Originally Posted by Lamech

I also note that the children of the Incubi will probably evolve to be manipulative to get as much in the way of resources as possible. Possibly have some method of faking sickness or whatever. They lack the pressure of kin-selection, that otherwise prevents this. On a final note if its a chimera most things don't need to be replaced. Some changes to the brain to increase social/manipulating skills, the reproductive system, and some way to identify each other; finally any better adaptions that they have evolved will be in the final incubus.

I'm not aiming to make them social monsters. As I said, I envision them having a rather passive strategy. Also, they are definitely not interested in 'overwhelming' the other species - they need others to keep existing, remember.

[vicky_molokh]

Originally Posted by Bruno

Transferring gametes to the "Male" already has a precedent, see seahorses. He could hold the female eggs unfertilized until he finds an opportunity to um "infect"? a host.

Seahorse genitalia are not the same as human-like genitalia - neither anatomically nor functionally. I understand that in general, such a mechanism is possible. Is it possible without making the Sirkin visibly 'freaky' to other humanoids?

[Sunrunners_Fire]

Allow me to restate my understanding, and you can tell me where I'm off.

• Incubus:
  • ... mates with male human, temporarily infects male human with their genetic information so that the male human carries both Human and Incubus genetic information; if infected male human successfully impregnates a female human or Succubus, the resulting pregnancy produces a Human, an Incubus or a Succubus.
  • ... mates with a female human, and successfully impregnates the female human, with the resulting pregnancy producing a Human, an Incubus or a Succubus.
  • ... mates with a Succubus, nothing happens.
• Succubus:
  • ... mates with a male human, and is successfully impregnates by the male human, with the resulting pregnancy producing a Human, an Incubus or a Succubus.
  • ... mates with a female human, temporarily infects the female human with their genetic information so that the female human carries both Human and Succubus genetic information; if the infected female human is successfully impregnated by a male human or an Incubus, the resulting pregnancy produces a Human, an Incubus or a Succubus.
  • ... mates with an Incubus, nothing happens.

... am I understanding the desired behavior correctly? If so, it doesn't break my Suspension of Disbelief. Its' complicated, but not unnecessarily so. They're in symbiosis with humanity, using humanity to reproduce even as humanity also uses them to reproduce.

If they can successfully mate with each other, then they should also have the chance of producing human offspring instead of incubus/succubus offspring, otherwise they'll end up subverting the human species until all that is left are the incubus/succubus.

[vicky_molokh]

Originally Posted by Genesis

I furthermore suggest that the females aren't a problem either. Sirkin gametes must still combine with Sirkin gametes to produce children. Perhaps there's a minimum number of parents, without which a functioning fetus cannot grown! Perhaps the males and females don't carry the same genes, and proto Sirkin don't become viable until they've got copies from each sex!

That one seems best when it is required occasionally, but not necessarily every time. IMHO.

Originally Posted by Genesis

If this last is the case, consider that the distribution of children from a male and female Sirkin would look very different. A female Sirkin might leave a limited stock of viable gametes with a male, which will may quickly exhaust themselves if they lack the means to reproduce (for the sake of stealth it seems only wise for this to be the case). These gametes then have to find their way to the uterus of a host female who has also interacted directly with a male of the Sirkin species. The two genders might have "transitive sex" with the potential host. If this was the case, females might "father" multiple Sirkin children with a single sexual act, while males would require a different act, with a different host, for each offspring. Depending on the proportions in the species this could make things interesting....

Are you referring to anatomical males/females or genetic males/females? As can be seen from the discussion, it is quite possible that a.m. is g.f. and a.f. is g.m.; or even that there are no genetic sexes at all.

Are you proposing that the same host must have a direct intercourse with two different Sirkin? That seems like a very difficult strategy.

Originally Posted by Genesis

Even if you don't need genes from both sexes to form a viable offspring, Sirkin would still "prey" primarily on the sluttiest people and races possible. It would be in a female Sirkin's best interest to seduce the most promiscuous human males around (which introduces a great "prey on the predator" potential dynamic...), while males might actively seek out the recent human partners of such "studs" and compete to bed them while the female gametes (with their valuable genes) are still viable.

And that is assuming one of the gonad takeover schemes is in place.

Originally Posted by Genesis

Actually, this is a great race. I'm totally making a Lovecraftian-style horror race that does exactly this for my current game...

Okay, it's your game. But in my game, I'm trying to make them true symbiotes useful to the other race. Right now I'm planning to play up their mathematical and general academic aptitude, and make them the designated movers of scientific and technological progress in locales where their numbers are significant enough to notice. Perhaps low-tech cultures would never put two and two together, and think that birth of a Sirkin is some sort of blessing in the family. :)