Why the Sentient Species Don't Make Mutts

[jqavins]

Over in this thread there's been a discussion about why D&D races (or those in similar game systems) don't all interbreed until the whole world is populated by mutts. It's a fair question, though there are also many equally fair answers. Here's mine, and I invite comments.

I'd already decided that elves and dwarves, and others yet to be decided, are "fey-touched." They had hominid pre-historic ancestors and were modified by magic that is associated with an element or a natural force. And that orcs, goblins, and maybe ogres (I keep going back and forth on ogres) are hominids, closer to homo sapiens than chimps, gorillas, and orangutans, almost but not quite as close as neanderthal.

The fey-touched can't interbreed with with any other race without magical intervention, and the offspring are basically infertile. (They might have offspring with even more esoteric magical intervention.) Also, social mixing of these races is rare due to geography; each is dominant in a different area but separated by difficult mountains. So half breeds are rare but possible, and virtually never propagate.

The hominids (including humans) are totally inter-fertile, but their offspring have less than a 50:50 chance of being fertile (without magical intervention.) And they are largely though not overwhelmingly separated by a variety of social factors; basically, they mostly don't get along and don't like to mix, though there are a decent number of exceptions. So, while half-breeds are not too uncommon, mutt lineage tends to die out.

[Dusk Raven]

Interesting. If this is an idea thread, then what happens in my own setting is that humans are the only humanoid that can breed with others. The resulting half-breed can reproduce with either of the parent races, but no others, although I think if you have at least a three-quarters human (with variation), then that individual retains the reproductive viability of humans, leading to things like elves having very distant Orc ancestors and probably no phenotypes from them.

'Course, that was before my setting revamp, in which humans were the base template from which the creators of humanoids made all other humanoid races... not sure whether to keep that.

[jqavins]

although I think if you have at least a three-quarters human (with variation), then that individual retains the reproductive viability of humans, leading to things like elves having very distant Orc ancestors...

Not necessarily so distant. Consider

Human────┬────Orc
         │
      Half-orc────┬────Human
                  │
            Quarter-orc (75% Human)────┬────Elf
                                       │
                                   Half-elf (12.5% Orc)

Thus, a half-elf an orcish great-grandparent. How distant do you want the (in this example) orcish ancestor to be at a minimum? Each new generation back means half the allowable contribution to the lineage.

Generations Back	Percent Human
1	50
2	75
3	87.5
4	93.75
5	96.875
6	98.4375
7	99.21875

Which makes sense (to me) because if you want the non-human part to be washed out enough not to have any appreciable effect (on fertility or phenotype) then it should be a really small percentage (in my opinion.) Of course, that's not really how genetic inheritance works, especially with small parts of one species. You'd be more likely, as I understand it, to get select discrete characteristics popping up, so you should really get a possibility of fertility with the probability increasing as the non-human part is more and more diluted. Unless my genetic understanding is out of date or just plain wrong, which is entirely possible. And that may be taking the science too far for; it's just a game.

Can mixed breeds re-breed with non-humans of their own ancestral species? In other words, where I have a quarter-orc above, would a 3/4-orc be possible?

And, if yes to the above, then Percent Human values in between the values in the table are possible. (A 3/4-orc breeds with a human and you get a 3/8-orc, or 62.5% human, for example.) You really, with enough mixing of mixes, can get any fraction you want as long as the denominator is a power of two. You can't get 1/3, but you can get 43/128, which is 33.59375%, with seven generations of breeding. Or 341/1024, 33.30078125% with ten generations. Etc. I had a point; where did it go? Oh yeah.

With reference to the table, if you want to say the mixed race parent has to be at least (for example) 80% human, don't worry that 80% isn't one of the possibilities in the table. If there's only one humanoid ancestor it would have to be at least three generations behind the possible parent (four behind the offspring) but if there are multiple humanoid ancestors at various distances then someone really really close to 80% could very well be walking around. (819/1024 is 79.98046875%.)

[Dusk Raven]

Not necessarily so distant. Consider

Human────┬────Orc
         │
      Half-orc────┬────Human
                  │
            Quarter-orc (75% Human)────┬────Elf
                                       │
                                   Half-elf (12.5% Orc)

Thus, a half-elf an orcish great-grandparent. How distant do you want the (in this example) orcish ancestor to be at a minimum? Each new generation back means half the allowable contribution to the lineage.

Generations Back	Percent Human
1	50
2	75
3	87.5
4	93.75
5	96.875
6	98.4375
7	99.21875

Which makes sense (to me) because if you want the non-human part to be washed out enough not to have any appreciable effect (on fertility or phenotype) then it should be a really small percentage (in my opinion.) Of course, that's not really how genetic inheritance works, especially with small parts of one species. You'd be more likely, as I understand it, to get select discrete characteristics popping up, so you should really get a possibility of fertility with the probability increasing as the non-human part is more and more diluted. Unless my genetic understanding is out of date or just plain wrong, which is entirely possible. And that may be taking the science too far for; it's just a game.

I was more thinking they had a couple of generations breeding with humans before one of the resulting humans breeds with an elf. Still, I consider great-grandparents reasonably distant, if only because I have no living relatives that far removed. I think the "three-quarter" rule here works fine. As for genetics, well, while I loathe to simply through out the laws of anything, since this is a fantasy setting I can simply say, "Genetics don't work that way in this setting." That's something I've recently realized about fantasy settings - so long as you come up with something to replace it that makes sense, you can toss out anything. I could have it so that genes are inherited entirely through mitochondria, or remove the entire system of DNA (to say nothing of getting rid of cell theory). It's not like the people in the setting will know the difference.

...Kinda want to make a thread about that now, about ways to plausible handwave away real-world conventions without just saying, "It's fantasy, you don't need to care about reality!"

Can mixed breeds re-breed with non-humans of their own ancestral species? In other words, where I have a quarter-orc above, would a 3/4-orc be possible?

Of course. They more or less count as human for breeding purposes, so they can breed with any humanoid. It'd be weird if they could breed with any but their non-human parent species.

[Everyl]

For my own part, one of the reasons I brought the racial muttification issue up in the verisimilitude thread in the first place was because I ran into it as an issue while I was revamping one of my settings. I ran the setting as basically a fantasy kitchen sink when I was younger, and I'm trying to make it a little more internally consistent without violating/retconning too many of the things that happened in those earlier campaigns. I decided on a relatively low number of original progenitor races, with other out-of-the-book races representing fairly stable populations of mixed heritage (Example: hobgoblins and gnomes are progenitor races, goblins are basically an ethnic group of mixed hobgoblin/gnome heritage). I created sufficiently-isolated homelands for each progenitor race to explain why "purebreeds" still exist in large numbers after thousands of years of contact between races, but when I was working on a cosmopolitan region outside of any of the homelands, I realized that most of the people there would probably be indecipherable mixes of three or more progenitor races. I've been pondering solutions ever since, without much luck so far. Jqavins and Dusk Raven have good solutions, but they don't fit the lore of my setting.

Dusk Raven's solution definitely works well for many D&D-style games, where knowing exactly which race a character is has concrete rules mechanics. Preventing non-human races from mixing with one another directly avoids the possibility of characters with no distinct race, and makes it pretty reasonable to say that sufficiently diluted other-race ancestry is as good as none at all for all intents and purposes. I like it - it's simple, and plugs into most "standard" settings without affecting existing lore at all.

[Belac93]

In my setting, only high elves and humans can properly breed together, due to magical tampering on the elves part, and humans entire culture being based around adventure and new experiences.

Half-orcs exist, but they are really just a sub-breed of orcs that are less violent. Half dragons do exist, but only with humans and high elves.

[5a Violista]

I just had a random thought: what if the "human" race is the mutt race? It would explain why humans can breed most easily with everything, and it would explain why in many games humans have multiple different cultures (while other races generally have only one or two).

What implications would this have on the setting?
I don't know.

[LudicSavant]

it would explain why in many games humans have multiple different cultures (while other races generally have only one or two).

Not really. A lack of genetic differences does not explain a lack of cultural differences.

[jqavins]

Still, I consider great-grandparents reasonably distant, if only because I have no living relatives that far removed. I think the "three-quarter" rule here works fine.

OK. I hadn't considered how personal experience shapes what "distant" means, though of course it does. I had a living great grandparent when I was quite young, and so did my daughter, so it doesn't seem that distant to me. Also, you originally wrote "very distant," and it seems odd to me that anyone would call great grandparents very distant, but then a lot of things seem odd to me that are not important.

Of course. They more or less count as human for breeding purposes, so they can breed with any humanoid. It'd be weird if they could breed with any but their non-human parent species.

I must not have been clear. Once the 75% threshold is reached, then of course. I was asking about a 50:50. (If we continue to pick on half-orcs) a 50:50 half-orc couldn't breed with an elf, and could breed with a human; my question was could one breed with an orc?

[jqavins]

I just had a random thought: what if the "human" race is the mutt race? It would explain why humans can breed most easily with everything...

Ooh, I like it, I Like it. Except:

and it would explain why in many games humans have multiple different cultures (while other races generally have only one or two).

Not really. A lack of genetic differences does not explain a lack of cultural differences.

Yeah, that. I could offer an explanation, but a pretty thin one, in my opinion. The other races have genetically determined tendencies, very strong evolutionary psychological traits, that determine most aspects of their cultures. These are all mixed up in humans to such an extent that they either compete or cancel, allowing other factors to influence culture the way they do in the real world. That would also allow for greater cultural adaptation to varying conditions by humans than the other races, which helps explain their geographic range.

I'm almost managing to talk myself into buying that explanation, but not quite.

[5a Violista]

I was thinking more along the lines of “In order to maintain genetic purity, all the other races had to adopt isolationist and highly unified/nationalistic policies to prevent their people from devolving into humans“

But, y‘all are right: that could only work for very specific settings and wouln‘t matter in the overall picture.

[Jendekit]

In one of the many settings that I have, there is an explanation for why humans can interbreed with orcs and elves, but no one else can interbreed with the other races.

In the far, far past of the setting (~2-3mya) the sapient races that were around consisted of: Ebu Gogo, Shanidar, Turkana, and Ukuhleka. The Ebu Gogo eventually evolve into Dwarves and Halflings (no gnomes in most of my settings); the Shanidar evolve into orcs; the Turkana evolve into Elves and Humans; and the Ukuhleka evolve into Gnolls.

So how does this tie into interbreeding? Well humans and elves share a relatively recent common ancestor so they are genetically close enough to have offspring, though 8/10 those offspring are sterile. As for humans and orcs, the genetic line that became humans are the turkana that interbred with shanidar until ~1-1.5mya while the turkana that didn't became the elves.

So humans are closely related enough to elves and orcs that they can have interbreed, but they are the only ones of the sapient races that are closely related enough to do so.

Well I take that back, dwarves and halflings could theoretically interbreed, but they live in such different environments that they are highly unlikely to do so.

[Balyano]

In certain animals a process called hybridogenesis can occur when a hybrid reproduces.


Essentially the chromosomes inherited from each parent will remain unrecombined and will separate during gametogenesis.


The result would be that a half-orc female would have half her eggs be 100% orc and half 100% human, rather than a random mixture of the two species genetics. This means that if she bred with a human half the children would be half-orcs and half would be human. No quarter-orcs.


In some hybrid species one species' genome is selectively deleted over the other.


If that were to occur, and say it was the human side that gets deleted. Then that half-orc woman would always produce half-orcs with human men and pure orcs will orcish men. This would make breeding with humans a viable option for an orcish tribe, they bolster their numbers, and in a generation the ''weak'' human side is all gone.


In some species that do this matings between two hybrids produce malformed and often sterile individuals. So it's possible that the half-orc woman can only produce young with an orc or a human, but not with another half-orc.

[sktarq]

Actually that (^) would be interesting. If Human genetics say overwhelmed elf and orc genetics overwhelmed human it would set up the often cliché but useful declining elf and numerically threatening orc populations.

Also I know at least 2e did cover what would happen to true mutts-the Mongrelman entry in the Monster Manual is for that very thing

[AtlasSniperman]

I didn't see any mention of the race mongrelfolk(races of destiny page 98). So having namedropped it, I shall leave it.

Personally, I my setting I don't have the humanoid races close enough genetically to even allow halfbreeds.
Dragons and outsiders can breed with humanoids fine and produce fertile offspring as(at least in my setting) they magically change to use the dna of the race they're mating with, plus some extra chromasomes to account for other stuff. So half-demon, aasimar etc are syndromes in my world.

But in general I don't allow halfbreed races(half elf, half orc etc) as I'm just not a fan of having the genetic closeness at what it implies.

[JoeJ]

Among humans in the real world, men of the Efe people of central Africa average 4' 8" (142 cm) tall. Only a few hundred miles away, men of the Dinka people average over 5' 9" (176.4 cm) tall. Women, in both cases, are slightly shorter.

Perhaps the same processes that keep human groups from homogenizing also work between humans and other races.

[Mechalich]

In my setting the sentient species almost never cross-breed. The various cross-breed species are instead true-breeding species of ancient origin. So 99% of, for example, half-elves you meet had two half-elven parents. There are various historical explanations for how these true-breeding hybrid species originated (lots of population manipulation by Hags mostly), but interbreeding is not something that actually happens in the present beyond a minute frequency. Additionally, most populations of non-human races are geographically segregated - they exist in small scattered patches where they are the dominant species, rather than spread out evenly among the human majority.

[Tiktakkat]

http://www.nytimes.com/2016/03/22/sc...tionfront&_r=0

Apparently sentient species do make mutts.

[Lycanthrope13]

Could always be something as simple as chromosomal differences. There are plenty of real world examples of creatures with similar morphology who are unable to interbreed due to genetic incompatibities. The offspring are either infertile or completely non viable.

[Mechalich]

http://www.nytimes.com/2016/03/22/sc...tionfront&_r=0

Apparently sentient species do make mutts.

The implication of this research is that widely separated populations of proto-humans or very closely related species of the same interbred on rare occasions and that some of the genetic material resulting from those crossbreeds was conserved and eventually spread throughout the total human population over vast numbers of generations. Given how gene flow in humans works - in that if you have descendants at all, eventually everyone alive is your descendant - that's not really 'mutts.'

It is totally possible to have some low-level of active gene-flow between closely related species without the populations hybridizing into one species. Exactly how much is a matter of some debate and also depends on additional factors such as the total size of the population, the amount of genetic variance within the species to begin with, and the nature of the reproductive process in a species.

If cross-breeds are rare - and a good approximation would be Tanis Half-Elven, whose very name implies just how rare such things are in Dragonlance - then it's not a really path to hybridization.

[Tiktakkat]

Given how gene flow in humans works - in that if you have descendants at all, eventually everyone alive is your descendant - that's not really 'mutts.'

And yet "mutts" was the term used for interbreeding species in a fantasy setting.
And to prevent it, you must apparently impose a fantastic alternative to realistic gene flow.

Or quirk "natural" populations.
Or impose restrictions on "natural" interbreeding.

Which would ultimately, going back to the thread that spawned this one, break verisimilitude in a campaign.

[Tody Shelfungus]

And yet "mutts" was the term used for interbreeding species in a fantasy setting.
And to prevent it, you must apparently impose a fantastic alternative to realistic gene flow.

Or quirk "natural" populations.
Or impose restrictions on "natural" interbreeding.

Which would ultimately, going back to the thread that spawned this one, break verisimilitude in a campaign.

This assumes that all are actually one Species. Assuming that they are not would require fantastic alternative to create a Mutt.
For my milieu, a Half orc is a child of a human and Any of the goblinfolk tribes; goblin, hobgoblin [land, river, sea], Bugbear,... who takes after the human side.

The Halfling subraces creation including the brownie, are not discussed by halflings even those subraces. In my campaign this has something to do with some Halfling Housekeepers...

| "My vision of half orcs is even more complicated, in my world an Orc is any mixed blood of the goblin folk; Goblins, Hobgoblins, and Bugbears. Among themselves Orcs breed true.. Mostly, sometimes a young one is born that smells and looks almost pure goblin, hob or bugbear and these usually get dumped in the nearest nursery of that type.
| In my world a half-orc is the child of a human and any of the goblin-folk tribes including orcs. Now as the 1/10th that look like the goblin-folk parent they do look like the original type; Orc, Goblin, Hob, Bugbear but are still considered Half-orc because they smell wrong and are still one HD.
| About the half orc the 9/10 side is defined by their looking most human. They are by nature defined by the half orc stat block, if a player wanted to play a 1/10 side I very likely would ask them to start with a goblin, hob (even) to being born with vestigial gills, or bugbear stat block. But being allowed to make development choices as if both races.

| Now as to the Faery folk.. I don't have such a mix on this side of the "Hedge". You notice some of the Fae type creature use dimension door blink and the like, while I see the "Standard" elf, dwarf, gnome, and halfling as the Grounded set of the fae clans. Such a group/clan shares with the other fae the ability to in some way "cross the hedge" to the border ethereal. But this is only, One- after Oath Bonding to a Prince [elf and dwarf], High Shire-reeve [halfling], and Beast Marshal [gnome]. Two- settling in land near to their master, they can then over time create a doorway to the first half of the boarder ethereal [tamed land] it is touched by in its casting by a major terrain illusion created by the chief that makes it match the "Real" lands it touches. A maker of such a "local door" can warp the Tamed (or tainted, depends on who you ask) Land that is its living place to its will. These Chiefs can also create Faery Gates woodland mazes whose path will lead one from that maze to a twin (though the twin of the tree you are looking at might be a very large mushroom or stalagmite). This can create links to major Faery planes, and even the Mushed vita-elemental planes of Riot, Faery, and Dream.
| This all does have a point based on your question.

Any racial mixing takes place beyond the hedge the farther the more completely strange it can be. I.E. you know those half elemental character races, guess where they might have been conceived and born. But locally the best example would be the halfling clans that live near another race. A halfling house keeper who falls in love with her bachelor housemaster can begin to draw the household itself beyond the hedge if the master returns the feeling in depth (soul bond). While you can call it Illusion that close to actual creation of life they become what they need. That is one reason local halflings begin to appear related to the local non-halfling settlement. The households’ children often appear to live with her relatives. But as there even distance must bend to a mothers will, the child's bedroom often has a straight door to daddies household. Halflings have a phrase "Stubborn as a housemaid!" While these children may be mixed halfling, they are not half anything. The children are born all halfling though sharing some of the father’s looks.
| Now I won't say this doesn't happen with the other fae races but this for them is all less domestic. The child is always the race of the mother, now elf maids and elf men don't have to go to all the trouble and soul bonding to make it work with humans so that is why you end up with actual half elves"

IE.. The Question may not be, Why not, but Why ever.

[kardillamo]

I think another big thing is that alot of mutts can be sterile due to certain gene expressions. Look at Horses and Donkeys, they produce mules, but most mules are completely sterile. It's the main reason most of my races haven't interbred.

[2D8HP]

I just had a random thought: what if the "human" race is the mutt race? It would explain why humans can breed most easily with everything, and it would explain why in many games humans have multiple different cultures (while other races generally have only one or two).

What implications would this have on the setting?
I don't know.

It long ago occurred to me that since they are Elf/Human and Human/Orc "mutts", why not Elf/Orc? Then I had the thought, "of course humans". What killed the idea was that unlike both Elves and Orcs, Humans don't have any low light vision. I'd love to learn how to make this work.

[Balyano]

It long ago occurred to me that since they are Elf/Human and Human/Orc "mutts", why not Elf/Orc? Then I had the thought, "of course humans". What killed the idea was that unlike both Elves and Orcs, Humans don't have any low light vision. I'd love to learn how to make this work.

I would say they work on different mechanisms that are recessive traits.

Perhaps one has lowlight vision due to a high concentration of rod cells in their eyes and the other has it due to having a reflective layer behind the retina that gives their rods a second go at the light. This could mean that orcs eyes shine in the dark like a cats, it would also make their vision a bit more blurred. Elves don't have the reflective layer so the image quality of elven vision is superior to orcish vision.

Of course in previous editions one has darkvision the other has lowlight. Which probably work on different mechanisms than eachother.

Of course the question becomes ''why doesn't lowlight or darkvision show up in humans often?''

If humans originated as a hybrid, first generation hybrids didn't have the lowlight/darkvision, they couldn't compete with elves or orcs in the dark so they had to be most active out in the sun. Individuals from later generations that had lowlight or darkvision joined elven or orcish culture. After a few generations the genes for lowlight and darkvision become so rare in the day living hybrid decendants as to be non-existant.

Problem with this is half elves and half orcs have those vision traits.

Well if its a polygenetic trait with one partner being dominate and the other recessive then this can still work.

AA/BB or Aa/BB required for lowlight vision
CC/DD or Cc/DD required for darkvision

BB and DD have additional advantages unrelated to lowlight and darkvision and so are selected for.

Elf AA/BB/cc/dd
Orc aa/bb/CC/DD

Hybrid Aa/Bb/Cc/Dd - this hybrid is a carrier for both but lacks either vision trait

The decendants of Hybrids with any of these genotypes join their crepuscular/nocturnal relatives

Spoiler: Probably missed a few

Show

AA/BB/CC/DD - Aa/BB/CC/DD - AA/BB/CC/Dd - AA/BB/Cc/DD - AA/BB/CC/dd - AA/BB/Cc/Dd - AA/BB/cc/DD - AA/BB/Cc/dd - AA/BB/cc/Dd - AA/BB/cc/dd - Aa/BB/CC/DD - Aa/BB/CC/Dd - Aa/BB/Cc/DD - Aa/BB/CC/dd - Aa/BB/Cc/Dd - Aa/BB/cc/DD - Aa/BB/Cc/dd - Aa/BB/cc/Dd - Aa/BB/cc/dd - AA/Bb/CC/DD - Aa/BB/CC/DD - AA/bb/CC/DD - Aa/Bb/CC/DD - aa/BB/CC/DD - Aa/bb/CC/DD - aa/Bb/CC/DD - aa/bb/CC/DD - AA/BB/Cc/DD - AA/Bb/Cc/DD - Aa/BB/Cc/DD - AA/bb/Cc/DD - Aa/Bb/Cc/DD - aa/BB/Cc/DD - Aa/bb/Cc/DD - aa/Bb/Cc/DD - aa/bb/Cc/DD

any other genotypes remain daydwellers

but ones that are BB and DD have advantages over the others, no sure what those adaptation are, but they cause them to be selected for, after a few generations they are fixed in the population.

Perhaps bb is associated with sunlight sensitivity, a horrible trait for a diurnal creature.
And DD is associated with short lifespan - so those hybrids mature faster and out breed their longer lived relatives.

Humans end up with this genotype
aa/BB/cc/DD

Half elves have
Aa/BB/cc/Dd - lowlight vision

and half orcs have
aa/Bb/Cc/DD - darkvision