Topic: Why is there only one race of Humans on Earth ??

[rdanhenry]

Except that groups that can interbreed don't necessarily combine, they can also diverge over time. That's how speciation happens in the first place, in our evolutionary world.

Are you committed to a future in which horse and donkeys merge into one species? Because mules aren't all sterile. They're mostly sterile.

Once the peoples are in regular contact and interfertility is allowed, it is certainly likely that their populations will merge over a long enough time span but (a) that's pretty much irrelevant if the setting is after only a relatively short period of contact and (b) over a long enough time span neither species is likely to survive as itself anyway so the interbreeding issue may well be moot depending on its pace.

Then again, human DNA is more virus than human (there's more material from a single viral source than there is in active genes), so one might argue that elven disease resistance would kill the human genetic material and that this would prevent interbreeding.

I'm certainly not advocating having half-breeds just because you've got stats for them, but if they serve some function in the setting, they don't invalidate it.

[Marc R]

I concur that in setting time spans they exist, and the mule argument is akin to the previous god one. . .if reproduction is under control of an outside force (humans for mules, gods in a hypothetical setting) then indeed the eventuality of merger can be trumped by an exterior force with complete control.

On the flip side, Dogs, Wolves, Dingos and Coyotes are all just dogs, and calling them different species is kind of a crock of nonsense, they all interbreed and are merely just regional variations. . .the Chihuahua and the St Bernard are just dogs, and despite radical variations in structure and appearance are still the same thing. The dog has a wide range of morphology within it, which resulted in pre-genetic classification of many species of dogs, but based on genetics they're really just isolated genetic pools of one species with some variant characteristics.

IMO a game world where elves, humans and halflings can all mix casually. . .then IMO they're all just one species. . .one happens to be short, one happens to be long lived. . .

If whatever caused those populations to diverge is removed, likely they'll re-merge back into a singular genetic pool.

[Kristen Mork]

On the flip side, Dogs, Wolves, Dingos and Coyotes are all just dogs, and calling them different species is kind of a crock of nonsense, they all interbreed and are merely just regional variations. . .the Chihuahua and the St Bernard are just dogs, and despite radical variations in structure and appearance are still the same thing. The dog has a wide range of morphology within it, which resulted in pre-genetic classification of many species of dogs, but based on genetics they're really just isolated genetic pools of one species with some variant characteristics.

Dogs and wolves may be able to interbreed, but they have some large racial differences.  Dogs have many traits that help them live with humans that wolves can't learn.  So, despite genetic similarity, they are quite different creatures.

[Skaran]

To get half half combinations naturally, the species have to be very closely related in the first place. Many off spring of such combinations can be sterile (mules for example) some are fertile but subsequent generations may dilute differences.

So take half elves - the elf and human have to be genetically close enough for an offspring to be viable, this would imply to me a relatively recent common ancestor. In game half elf-half orc seems very rare whereas half elf-half human and half-human-half orc etc seems much more common. I would theorise that this gives two possible evolutionary paths.

1. Elves - Humans - Orcs etc all have the same recent common ancestor. Probably from a human line as this seems the most viable and widespread half contributor.
2. Elves and Humans have the common ancestor and orcs are descended not from Elves but Humans.

Other theories can easily be thought out if you want a 'natural' evolution.

[Cormac Doyle]

One must also remember that interfertility is not a simple either/or matter. There's a good deal of practical difference between situations in which 100% of elves can interbreed with 100% of humans and one where 10% of elves can interbreed with 10% of humans or one in which 2% of elves can interbreed with 3% of humans with reduced chances of conception and increased chances of miscarriage.

Species is not as "hard and fast" as you may think

There are three major Gull species in the northern hemisphere. The American Gull can interbreed with the European Gull. The European gull can interbreed with the Asian Gull. The Asian gull cannot interbreed with the American Gull. Is that 1, 2 or 3 species ??

As to the genetic basis behind disease resistance ... that is not an on/off toggle. People from "malaria"-prone regions should develop an enhanced genetic immunity to malaria if that was possible, right? Right - it's called cycle-cell anaemia. A "carrier" for cycle-cell has a dramatically reduced chance of having malaria, but a 25% chance of having a child with cycle-cell. Look at the numbers ... cycle-cell is less disruptive than malaria (at least until modern medecin), so it was a feature that was "selected for"

[Cormac Doyle]

sorry - sycle, not cycle

[Marc R]

Dogs and wolves may be able to interbreed, but they have some large racial differences.  Dogs have many traits that help them live with humans that wolves can't learn.  So, despite genetic similarity, they are quite different creatures.

Most wolfdog advocates would say that's propaganda put forward by people who's political agenda is to make it illegal to own wolves or part wolves as pets, and that you'd likely have similar problems attempting to make a pet of a wild dog. Of the dog species I listed above, all are now considered Canis Lupus except for the Coyote, which is on it's way to happening IMO. Domestic dog's separate specification as Canis Familiarus was demoted to Canis Lupus Familiarus, and the genetic qualifications for a subspecies are so weak as to be borderline meaningless. I guess technically all the above are not dogs, they are all wolves. (A Hyena or a Fox, that would be an actual, different species within Canis).

The dog/wolf comment was less in line with arguing about dogs and wolves than it was to point out that vast swings in morphology and apparent characteristics are possible within a species.

As a for instance, having say Goblins, Hobgoblins, Bugbears and Ogres all be the same species seems gut "Wrong" but simply because it's counter intuitive to have 3' and 12' humanoids be all the same species is trumped by the actual fact that a Chihuahua and St Bernard are the same species. (Or the fact that humans vary from around 3'-9')

So it's entirely possible that Humans and Halflings are the same species, just isolated genetic pools. . . .and likely it's even possible to stretch the bounds to draw elves in as well. (Which, if they can casually interbreed, would likely be true from a genetic standpoint).

As to the Gull thing, it's not even necessary to go that far. . .sometimes Man A and Woman B are infertile, but Man A and Woman C are fertile. . .without needing to go out and find a Chimp to complicate things, sometimes a mix just doesn't work. . . Likely if you trapped 1,000 of each gull inside a 1 mile dome, you'd end up with just one species of "Gull" after 100 years.

OTOH if gods and trans-dimensional entities and/or mad scientists/casters are afoot, you could end up with 100 variant sapients in a quick time frame, the ones that can interbreed will likely quickly cross over into one pool over evolutionary time scales, unless something specifically and absolutely maintains a separation. . .Evolutionary time scales can be so long as to be meaningless in game time though, unless any one of us has run a campaign that actually ran for a hundred thousand year time scale? (Then again, on the flip end, I have been in games where "The Last Dragon" was hunted down and killed, or Goblins were apparently completely exterminated. . .we humans have proven over our real history to be quite good at closing chapters on entire species in short enough time frames to be noticeable in game time.)

[Kristen Mork]

Dogs and wolves may be able to interbreed, but they have some large racial differences.  Dogs have many traits that help them live with humans that wolves can't learn.  So, despite genetic similarity, they are quite different creatures.

Most wolfdog advocates would say that's propaganda put forward by people who's political agenda is to make it illegal to own wolves or part wolves as pets, and that you'd likely have similar problems attempting to make a pet of a wild dog. Of the dog species I listed above, all are now considered Canis Lupus except for the Coyote, which is on it's way to happening IMO. Domestic dog's separate specification as Canis Familiarus was demoted to Canis Lupus Familiarus, and the genetic qualifications for a subspecies are so weak as to be borderline meaningless. I guess technically all the above are not dogs, they are all wolves. (A Hyena or a Fox, that would be an actual, different species within Canis).

We know that wolves can be easily domesticated.  We also know that dogs can follow a person's eyes or finger to determine what that person is looking at or pointing at, but wolves cannot.  It would be interesting experiment to see how long it takes a group of wolves, after domestication, to develop this trait.  (Interestingly, dogs do not follow each other's gazes, only a person's gaze.)  I doubt there's a genetic basis for the trait, but it has become instinctual in dogs.

The point, I guess, is that there are distinct differences among populations that belong to the same species.  So, just because humans can all reproduce with one another doesn't mean there aren't different races.  After all, humans and elves can reproduce, but they are generally considered to be distinct races.  (Does this suggest that nightvision is a learned trait and not a genetic trait?)

[GrumpyOldFart]

As a for instance, having say Goblins, Hobgoblins, Bugbears and Ogres all be the same species seems gut "Wrong" but simply because it's counter intuitive to have 3' and 12' humanoids be all the same species is trumped by the actual fact that a Chihuahua and St Bernard are the same species. (Or the fact that humans vary from around 3'-9')

The various species of "giants" in my world are all mutations of dwarves.   

[Marc R]

Behavioral traits are hard to tie down, like wild dogs won't follow a finger either, suggesting that is likely a nurture rather than nature aspect. Wolves as a domesticated breed are said to be aggressive and dominant, and yet specifically fight bread dogs are even more aggressive and dominant on average than wolves . .suggesting on the nature side of it, domestic dogs are merely a far broader genetic spread than natural wolves. (Much like modern man is a far broader morphology and genetic spread than prehistoric man) but in the end, they're just wolves (And genetic studies of wolf and coyote populations indicate lots of cross breeding and crossing with dogs, two of the NA species are likely actually just expanding populations of coyote/wolf hybrids, part of why I think we'll see Coyotes redefined as Canis Lupus eventually). . .and if you mix dog breeds via cross breeding, they regress back into wolf/coyote like mongrel-mutts rather quickly, showing that most of the variation from dogs to wolves lie in recessive genes aggressively selected by breeders.

But, coming full circle back to the original question, if you want to look at a fantastic situation and apply science to it, you run into the issues raised on this thread. . .and all too often, the answer lies in the GMs view of things. Any two worlds will have totally different answers to these questions.

Like Kelewan of the Riftwar saga explained their races as the results of genetic tampering, plus some trans-dimensional migrations via "Rifts". . . .and in that world, none of the races could interbreed except different sub races of elves who could breed with each other.

In other worlds you have Moreau like stuff going on. . .and in others, there are just multiple sentient races with no explanation given.

[arakish]

Just wanted to throw my two cents in.

On the world I am currently working on, there are five different races playable by PCs: Alnara Altais, Gurandi Dangro, Krenosi Lillar, Muranin Rakana, Sualgar Grigin.  However, these are races in only the sense that Chinese, Caucasian, Negroid, Hispanic, et. al. are different races of humans. 

Actually, Project Genome has proven that there is only one human race.  But there are four different types: Negroid (African), Abiriginoid (Australia/Indonesia/Brasillian aborigines), Mongoloid (oriential), and Caucasianoid (occidental).

There are three other races not PC playable: Hatharnd, Nargthrin (Lumara), and Gulgal.  The Hatharnd and Nargthrin are similar to elves, but not elves.  Gulgal are similar to troglodytes/orcs. 

These three cannot breed with the humans. 

The Hatharnd and Nargthrin are completely incompatible due to their genes having a hexa-helix structure (6 strands instead of 2) structure and use 26 nucleotides (compared to only 4 for us humans).  In our genes, our 4 nucleotides only come in 2 base-pairs.  With the Hatharnd and Nargthrin, their 26 nucleotides come in 13 base-pairs.

The Gulgal, like humans, also have a double helix but they have 6 nucleotides in 3 base-pairs.

That is how I kept them from interbreeding.

rmfr

[Grinnen Baeritt]

There are two.

Men and Women.

Neither truly understands the other.