[Space/Aliens] Reproductive Features: alien, exotic and weird ideas

[vicky_molokh]

Greetings, all!

For some reason I'm in the mood for making up and sharing, and seeking out some setting-building ideas. Not sure I'll make anything out of it, but they might be used in a re-haul of one of my settings. Anyway, recently I've read some wiki articles on the more unusual reproductive systems (marsupial anatomy, bee genetics, traumatic insemination etc.), and realized that I want to make a list of reproductive features useable in science-fiction settings (because the ones found in Celestial Ocean only fit fantasy worlds). So, here are some, for a start (but I'm willing to read other ones - whether yours or someone else's):

• Three sexes, as in the Player of Games by Iain M. Banks: the male, female, and the 'apex', whose function is basically the transit of spermatozoa. But that seems like a not-too-useful build from an evolutionary perspective.
• Parthenogenesis + use of some external event to create genetic diversity. Perhaps the Asari of Mass Effect are the most known example.
• Generation-linked dimorphism. I.e. generation 1 has the same traits as generation 3, 5 etc., while generation 2 has the same as 4, 6 and so on. Dimorphism itself might be either very or not very noticeable. If the species uses parthenogenesis, things are easy. If the species reproduces sexually, this can be set up with effectively 3 or 4 templates, depending on whether the male-equivalent has a single generation-based form or two.
• Normal insemination, cross-species gestation: males function pretty much like mammalian ones, but females lack a functional/meaningful uterus, and are hermaphromorphs instead. The ova are fertilized in the female organism, which then proceeds to hermaphromorph, and expel the germinated cells into a member of another species; the germinated cells pretend to belong to the gestating species. This seems like a good way for a physically weak or otherwise deficient species to put the expenses of pregnancy on a physically more fit one - if they can seduce the gestator-species.
• As above, but male actually takes/extracts ova from the female, and then does the seducing-other-species part.
• Parthenogenetic cross-species gestation + caste system: reproduction by implanting parthenogenetic ova into other species as above, but offspring can be of two castes: the fertile caste, with the prime function being introduction and hunting/warfare/etc., and the working caste, whose functions include more 'peaceful' work, as well as caring for any offspring that is not accepted by the cross-species surrogate-parents.
• Conditional parthenogenesis + conditional gender bias (probably pretty common in our world): unfertilized ova have a chance to start developing anyway, and always produce male offspring. Fertilized ova produce female offspring.

Comments and contributions welcome.
Thanks in advance!

[nerdvana]

Originally Posted by vicky_molokh

Parthenogenesis + use of some external event to create genetic diversity. Perhaps the Asari of Mass Effect are the most known example.

An excellent example of this is the short story titled "Mother". It was written by Philip José Farmer, and was originally published in the April 1953 issue of Thrilling Wonder Stories and can be found in the collection titled Strange Relations.

Summary: Eddie Fretts, opera singer and momma’s boy, and his mother are stranded on a alien planet where they are captured by hill-sized immobile gastropods. Eddie’s communication and accommodation with his captor is fascinating and brings a new meaning to the Stockholm Syndrome.

These creatures reproduce by summoning "mobiles" (other creatures) and chemically convincing them that they should scratch this one spot (inside the shell). This then causes babies to form and the "Mother" eats the "mobile" normally. Great story, a must read of classic Science Fiction even with these spoilers. :)

[DemiBenson]

David Brin's Glory Season where humans have genegineered themselves for the planet, which has a 3 Earth-year-long solar orbit. In summer, men are in mating season and try to persuade women to bear their children - it's a very complicated business affair with much negotiation. In winter, women's physiology switch to clone production, which still requires sex with a man to trigger a clone-pregnancy. But in winter the men aren't in mating season, so they're not interested and have to be plied with proper incentives (money, trade agreements, promises to bear children in summer).

The situation creates three societies living together but all needing each other.

1. The dominant one is clone lineages of women, each of whose progenitor found a business niche best suited by her genotype and raised a family of clones to meet that need.
2. The second group is men, who form are mostly wandering traders and shippers.
3. The third group is vars (for variants), who are the female children of sexual reproduction. They get kicked out of their clone-mother's house at adolescence and have to wander the world to find or create a business niche best suited by their genotype, and raise a clone family.

[talonthehand]

The science fiction webcomic Schlock Mercenary has a species with three races (male, female and muftale), where the males and females provide genetic material in sperm and ovum like with most mammals, and the muftale raises the newborn in a marsupial-like pouch for a year or so. Let me see if I can find a link...ah, here we are. It looks like a number of the newborns traits are determined by what hormones they're exposed to while they're in their first year, so the muftale, while not contributing DNA, still contributes to how the child turns out.

[Fish]

Interesting thought experiment. You could hardly do worse than to look at the various strange configurations on Earth.

Gender differentiation, for instance, could be achieved, through temperature. At a certain temperature, the offspring are always male; above or below that, female. Primarily this is done by reptiles, I believe.

There is also the example of the clownfish, which engages in sequential hermaphroditism. There is one female and one dominant male, forming a breeding pair; all the rest of the fish are prepubescent males. When the female dies, the dominant male becomes female, and a new male is selected.

Also consider the matter of offspring: generating new life forms takes extra calories. This can be done through sexual cannibalism, where the body of one parent is consumed by the other in order to provide the extra biomass with which to make the eggs. An extreme case is the angler fish, where the tiny male actually fuses with the large female and atrophies away until virtually nothing of him is left.

[Trachmyr]

Originally Posted by vicky_molokh

Greetings, all!

• Parthenogenesis + use of some external event to create genetic diversity. Perhaps the Asari of Mass Effect are the most known example.

I'll share what I use in my current campaign for the Selk race.

They use Parthenogenesis, but they must use bio-feedback (Read: Meditate on the desire to become pregnant) to begin ovulation. The Selk are effectively clones, all sharing the exact same DNA. But they express individuality by differing Dominancy/Recessiveness of genes.

The ovum is has a full set of chromosomes (26 +51 short synthetic chromosomes), but each pair is "inactive". Chemicals produced in the uterus can activate the individual pair, there is one such chemical per pair (like a set of keys). Depending on the mother's own Dominancy expression of her genes, the chemicals carry either a positive or negative charge, the charge of the Key Chemical that activates a pair, one of the genes will gain dominancy. Note that the Key chemicals produced don't always have the charge that corresponds to the mother's dominant gene, about 1:80 carries the opposite charge.

The ovum must have all gene sequences activated in order to "become fertilized", and if after about 11 days the ovum isn't fully activated, it aborts and the Selk menstruates.

-----------------

The Key Chemicals are produced in response to a physical trigger, that being orgasm. Thus sexual activity is required to fertilize the ovum (though a partner isn't actually required). Each time the Selk experiences that "Trigger", it releases those key chemical. However, the levels of chemicals produced are fairly low, requiring many "triggers" before fertilization usually occurs... however a sexual partner greatly increases rate of conception.

Key chemicals aren't just produced in the uterus, they are also produced in vaginal secretion and lactate, and they are produced in much higher concentrations. If these secretions come in contact with the mother's mucus membranes, the key chemicals will be absorbed into the blood stream, eventually to be deposited into the mother's Uterus (Key chemicals can also remain in the blood for up to three days). As expected, the key chemicals produced by other Selk will have charges that correspond to the Donor's gene dominances.

-----------

While this does not create Genetic diversity, it creates individual diversity [/I](2.4 Septillion Variations)[/I]. The Selk are a bio-engineered race, and their designer did not want the randomness of evolution to "plague" the species. In the designer's opinion, if evolution or diversity is needed, it can be done through genetic manipulation, the same as how the Selk were created to begin with.

[Vaevictis Asmadi]

Marine flatworm reproduction: all marine flatworms are hermaphrodites, with two penises each. When they decide to mate, they basically fence with their penises. The winner is the one who gets in the first touch. Sperm is absorbed through their thin skin, so the loser gets pregnant and has to spend time and nutrients gestating, while the winner doesn't have to contribute anything except sperm.



Alien reproduction systems in David Brin's Uplift universe:

The Gubru have three sexes: female, blue, and yellow. They mate for life in threesomes. The blue and yellow both have to fertilize the female's eggs to create viable embryoes. Gubru always hatch as sexless neuters, and those who are selected, in threesomes, to reproduce will start out competing with each other for dominance, then flirting as one member becomes dominant. Eventually they fall in love and molt. The dominant Gubru becomes the female (who provides 50% of every hatchling's genes) and the other two become her blue and yellow "husbands." Since Gubru are sentient, the competitions for dominance are long, drawn-out political campaigns, and the selection process is also a political and religious matter, handled by councils of elder breeding triads.

The Brma have four sexes: A and B have sex to create what we would call the ovum, while C and D have sex to create what we would call the sperm. Then A and C have sex to produce the zygote. I think A and C contribute more genes than B and D, but I can't remember.

Urs have two sexes: a large, sentient female and a tiny, sentient but dumb male. The males are small enough to fit inside the female's pouch, but she kicks them out once she lays her larvae in there. Once the larvae are large enough to survive on their own, she kicks them out too, and finds a new husband. The larvae are produced in large numbers and most are eaten by predators. Those who reach adolescence are taken in as apprentices and husbands by the adult females.

Traeki are really weird: Each Traeki "stack" is a collective organism made up of multiple "rings" which are separate symbiotic lifeforms. A stack can "vlenn," which means giving birth to a pre-assembled stack of several rings complete with their personalities, skills, and genetic memories already chosen by the parent. An individual ring can also sporinate or bud off baby clone rings. I think they can also have sex, flower-style, with other stacks to produce baby rings.



Yeerk reproduction in the Animorphs series: Yeerks are all sexless. To reproduce, three Yeerks have to fuse their bodies together into one mass of flesh. This kills them, but hundreds of baby Yeerks hatch from their corpses, containing genes from all three parents.



My own idea for an alien reproduction:
A species has a hive with an immoble, non-sentient queen, who produces multiple mobile, sentient "workers." Either the "workers" are all female, or they are all neuter. During times of stress, when it appears that the queen and hive might be in danger, or during really great times when the conditions and opportunity are right, the queen gives birth to fertile males and females. These can go out and find fertile members of another hive to mate with, and their children will be new queens, which they have to plant in a suitable location and defend until she is large enough to produce her own "workers." A heterosexual pair can have multiple children, but always one at a time. All types of "workers" are genetically clones of the queen, but phenotypically are completely different from her. The queen and fertile "workers" are long-lived, but the infertile "workers" might be short-lived.

[starslayer]

Don't nessassarily get hung up on 'male/female'.

Some microbacteria 'trade' genetic information between each other. If a species were to become intelligent but retain that early genetic ability they might have conscious control of this ability when breeding; in which case 10 goblaps get together, one of them molts a blank (a completely genetically void section of stem cells) then the ten of them take turns conferring traits until it is a whole genetic code then it starts to grow.

I'll give it my eyes, ohh your eyes are good so I will add my mathematical ability, ohh that would be an excellent pairing with my musical background...

Such a species would react to change very well as they can select the most efficent breeding traits in one generation to react to lean, and the most powerful but expensive ones in times of plenty. Depending on how strong there sense of individual rights are they might also purposely breed for tasks selecting traits suited for those tasks (Soldiers have higher 3d spatial senses, reflexes, and overall resilience) or could lead to more accountability for parenting (Why did you EVER think it was a good idea to instill your poor reflexes into your child!?!)

Another idea of note is a species that reproduces necromatically, in that they have either a mystical/psionic ability to raise the dead as a member of there own species or else grew up in close proximity to another similar enough species and developed some method of restarting a deceased corpse with new genetic data (viral or stem cell injecting that makes use of the existing framework).

Finally, viral reproduction: The major intelligent species transfers its initial genetic data to a 'host' via the injection of a powerful retro-virus, over the next while the hosts genetic data is overwritten by the virus until they too are a member of the virus species, and the process continues. Such a species might 'farm' there host species trying to instill better 'starting traits' so that once injected they result in a better 'child', or the species may have very little indemnification with there 'children' due to how little energy and resources are required to create them.

[Vaevictis Asmadi]

More from Uplift:

Traeki also breed rings to produce suitable components for stacks.

Several species in Uplift change back and forth between sexes over their lifetimes, due to various stimuli or by choice.

Another race (I don't recall the name) requires a symbiotic host to gestate their eggs. There is only one species that can gestate this race's eggs. Normally the host survives gestation and "birth."


Some more alien reproduction, from the Uplift book:

"Tandu are hermaphroditic. They exchange genes by eating the spore-pods of dead Tandu; once fertilized, they lay a dozen or so eggs at a time."

"Other Methods" from GURPS UPlift:
"Parents lay eggs in host creature, which is eaten away by the developing young. (Or perhaps the parents suffer this fate!)"
...
Mating may be fatal to one or all parents.
Young compete among themselves murderously, yet are sapient and grow up remembering how they killed (and ate?) their siblings. [Thri-Kreen and Tohr-Kreen in D&D are this way]
Yound are produced when an adult is torn painfully into many pieces, each of which grows up into a different adult with most of the parent's abilities but few or no memories; the adult is gone."


You can also look up Neogi reproduction, from D&D: http://www.dotd.com/mm/MM00225.htm
It seems pretty reasonable for an extraterrestrial species in a scifi setting, perhaps with a little tweaking.

[knarf]

Then there's the aliens of Enemy Mine. While they are technically parthenogenic, they can have a form of sex to mingle genes and are encouraged to do so every few offspring to ensure genetic diversity. The parthenogenic impulse is triggered by stress and the alien protagonist in the story becomes pregnant due to combat stress.