I've been trying to come up with a genetically plausible origin for dwarves, but with little success. By dwarves, I'm talking about the jolly and burly people similar to that of Tolkien's dwarves.

My questions is thus: "What would cause a species (preferably of a common ancestor to humans) to evolve into a short and muscular creature?"

Bonus points if they still live in caves, but it isn't really necessary.

Additional info (will be appended as necessary):

  • Magic exists in the world, but dwarves have little to no access to it.
  • The cause must be due to genetics (meaning, no stuff like their god created them that way or some witch caused them to look like that).
  • No precursor race to control their gene pool (meaning no stuff like breeding them for slavery purposes or whatnot).
  • Can be eugenics if you can provide a plausible advantage for them to choose to breed with those characteristics (meaning no forced eugenics)
  • They must become an entirely new species, but cross breeding with humans will be fine.
  • Might also be caused by the naturally available diet to them, but if so, must take into account that they don't become large again once they start developing (meaning they don't increase once they start eating the same thing humans eat)
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    $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$ – L.Dutch Jul 31 '18 at 8:51
  • $\begingroup$ To future readers: Important questions and clarifications by other people inside chat. To people in general: Should the topics discussed in the chat be moved to the question at hand? $\endgroup$ – Foolish Jul 31 '18 at 8:59
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    $\begingroup$ @Foolish Any valid issues with a post which are raised in comments should be responded to with edits to the post. Don't expect people to dig through a long comment thread in order to find pertinent information; put it in the question or answer, as appropriate. In this case, comments were moved to chat; in general, comments are essentially third-class citizens on Stack Exchange and can be deleted at almost any time for almost any reason. $\endgroup$ – a CVn Jul 31 '18 at 12:11

They are Neanderthals

If you are familiar with high fantasy and you look at recreations of Neanderthals currently being done with better and better levels of detail, you will immediately notice a striking similarity between the proportions of a classic fantasy dwarf and a Neanderthal (both body proportion as well as facial features). Give a Neanderthal a beard and you have a somewhat tall dwarf.

This provides a very obvious launchpad from which speculation can commence. Neanderthals had very large brains and we have no reason to believe they were any less intelligent than we were. They also had muscles and bones more similar to a real ape than a human, which provides a tremendous amount of physical strength, at the expense of some level of fine motor manipulation (not enough to stop tool use).

From this archetypical Neanderthal, we can speculate that a large, genetically diverse population were able to find a large cave system and began to live there. Why would they do this? Well, archaeologists and anthropologists believe that Neanderthal populations were largely wiped out because of the aggressive expansion of Homo-Sapiens, and not just in war. In many cases, Homo-Sapiens may have simply integrated Neanderthal populations and then bred them into homogeneity through integration. Let's say that there was friction between an expanding Homo-Sapiens population and an established Neanderthal population, and the latter, lacking numbers to either stand up to them in the open or maintain their unique identity if flooded with them, just took to the caves to avoid this competitor. They would have had to favor secrecy and avoiding open conflict. They would have had to rapidly adapt to a hostile environment with limited food sources (mostly rapid raiding excursions). Tool use would be in great demand immediately.

Let's say over a long period of time, cleverness (tool use, inventiveness) and small stature (to better move around in limited confines of caves) were favored. The group was able to set up satellite colonies by sending family units across valleys to mountain ranges on the other side. Infrequent trading between the satellites keeps the genetic base stable. Some inherent dislike for the big people keeps the advanced Neanderthals from interbreeding with humans. They stubbornly maintain their independence and survive primarily by remaining hidden from humans most of the time.

If you can solve the economic problem of living in caves (food supply underground) you have a plausible scientific explanation for dwarves.

EDIT Willk and I posted basically the same answer at the same time. He removed his, but he had a very good illustration to show the concept. enter image description here

  • $\begingroup$ Similar to the answer @Wilk gave, but chosen in favour to a somewhat better explanation concerning cave life. $\endgroup$ – Foolish Aug 1 '18 at 1:13
  • $\begingroup$ I like this one too. But I like the picture I found! Biggs I am deleting mine; maybe you will consider moving the picture to yours. $\endgroup$ – Willk Aug 1 '18 at 1:26
  • $\begingroup$ @Willk I like your picture too. Where is it? $\endgroup$ – JBiggs Aug 1 '18 at 15:43
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    $\begingroup$ @JBiggs: news.softpedia.com/news/… $\endgroup$ – Willk Aug 1 '18 at 16:24

Evolution depends on many things, the easiest to control in your story is mating pressures,

What we know about Dwarfs... 100% certain

  • They're shorter than average.

What Fantasy stories tell us about dwarfs

  • They are short
  • They are usually quite stocky
  • They like living underground
  • They always have beards (even the women sometimes)
  • They like mining for Gold, Silver, Mythril etc

Some sections of LOTR have Gimli give us more info that might be useful, ()some people believe there are no dwarf women (due to the beards) and that dwarfs are natural sprinters.

Now if that first section is to be believed, it may be because dwarf women look similar to dwarf men, or possibly, dwarf women are not as common as Dwarf men, This is the key!

Shortness is both genetic and environmental, generally speaking well fed children that have balanced diets will be taller than their parents. but what if they had the exact same diet as their parents had during youth? then in theory there would be no environmental change, so it forces it down to genetics.

If Gimli from LOTR is to be believed, Dwarfs are natural sprinters, not marathon runners. so why would this be, possibly because once they'd mined some Gold, or Mythril, or Handwavium... then they'd run back to the forge and smelt it and stamp it with their name. so speed was key. but what about short passageways, running down them would lead to banged heads... a lot of them. this could mean that they were slower and therefore either have their gold ore taken by another dwarf (or person of any race) or their accumulation of wealth would be slower as they'd be unconscious all the time.

Now if dwarf women preferred richer men do to that being the culture of dwarfs, then they would tend to favour shorter more conscious men, or at least the faster ones, which often were the shorter ones. and being that each woman would have her pick of many men, it could slowly remove the taller genes from the gene pool.

This same line of reasoning could be used for the other options, more time mining means more wealth so why live above ground and take an hour to walk down when you could just live down there, less distance to the gold, more time ming, more money. i think the key deciding factor with dwarfs is that if dwarf women are not as common, make this the case and everything can be explained by runaway Darwinian traits. think shortness and beards being the peacocks tail.

I appreciate this doesn't look fondly upon dwarf women, making them look like gold diggers, proverbially speaking of course. But it would be down to cultural differences, and is not intended to offend normal human women, especially those that read this.

Edit: as for their stockiness, when compared to Elder Scroll's Falmer, those creatures have very little in the way of fat for insulation against the cold of living underground, yes working would generate heat, but while sleeping underground like that they would burn through calories fast keeping themselves warm, which means more food (a limited resource underground) so being fat and short reduces surface area from which to lose heat while adding the insulation needed to retain it.

And as far as food goes, underground surface connected aquifers could provide a plentiful supply of fish, as well as cave fungus and lichen etc. while i've only ever been caving once, it surprised me just how much life is down there. in theory there's no reason why a dwarf cave would be any different

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    $\begingroup$ Interesting take on the cause. But if they spend less time above ground, then how do they eat? They're stocky, working folk, which means a lot of food. Plus, given the considerations you have, won't they end up into a creature similar to Elder Scroll's Falmer? Tunnel traversal would be optimised by being skinny and running on all fours. Maybe more muscles for mining, but complexion would be extremely white. How would that be addressed? $\endgroup$ – Foolish Jul 31 '18 at 9:37
  • $\begingroup$ Food could be whatever you'd like, underground aquafiers could provide a healthy amount of fish, fed from an above ground source, or connected to the sea, cave lichen/moss and fungus? fungii? whichever it is, could provide other forms of nutrition. and again any cave living creatures could be hunted as well, there's nothing stopping you form inventing a cave cow. i'll edit my answer for the sotckiness part $\endgroup$ – Blade Wraith Jul 31 '18 at 10:05
  • $\begingroup$ Also I'm not sure Falmers make sense, sight is still used by cave animals in real life, its just a bit limited, as Gold ore and Iron ore don't smell all that different (just a guess there as i'm not a dwarf/dog) and feel the same, seeing the glinting from a torch would be important to a dwarf. as for general appearance see above $\endgroup$ – Blade Wraith Jul 31 '18 at 10:15
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    $\begingroup$ I agree on the sight issue but the Falmer went blind mainly because the dwarves blinded them (quite amusing given the current topic). I was referring to their overall physiology that has been optimised in favour of cave dwelling. $\endgroup$ – Foolish Aug 1 '18 at 1:16
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    $\begingroup$ @Foolish, i'll be honest with you, I've not played elder scrolls so i could only gleam a certain amount of information from wikipedia, but i still think that heat retention would be a serious issue for them, forcing them to burn more calories to stay warm which means a greater demand on food. i think the short and stocky aspect would be of greater benefit, also allows them to store more of that energy if/when food is scarce .although i will agree complexion would most likely be very pale, unless pale was disliked by female dwarfs then again its down to desired trait selection $\endgroup$ – Blade Wraith Aug 1 '18 at 8:12

Photosensitivy genetic disease

This Powerful restriction drive people to avoid sunlight, therefore a subterran civilization could be a good place to be.

Have long hair and beard could be very useful to protect skin whenever going "into the light" is required, but not really useful underground --> perhaps only the "explorers" have beard or appropiate clothing for this task (sun glasses, hats..)


Being small and robust are positive traits for digging, rather than agile and tall. 6-pack dwarfs are more atractive?


A very useful genetic modification for dwarves that allow them to orient below surface AND detect magnetic anomalities (metallic ores, minerals, water) of vital importance to survivality.


A very big threat led the humans of a region to found refuge underground in natural caves.

The caves were providing the food they needed (mushrooms, algaes and fish of underground river) and the threat was so big outside that they stayed here. But with time passing, the threat managed to penetrate the caves and this people had to escape by tunnels to go deeper and deeper... These tunnels were very small and only the smallest "humans" escaped succefully…

This track lasted for generations and the only one able to go deeper were the holders of the small-size-genes. After a thousands and thousands of years, all of them were really small.

The underground habitat was pretty dangerous, creatures living in the depths were formidable ennemies and were so perfectly adapted to their environment that trying to avoid them by being discreet was useless and only resulted on be killed... Only the strongest and resistant dwarfs were able to live long enough to have kids when the frail ones died inevitably.

In the depth of the depth, the futur dwarfs finaly found the place where their transformation will reach its final form. They landed in a gargantuan cave covered with shinny gemstones, minerals and metal ores. Thanks to these light gems the dawrf kept their eyes similars to human's eyes. In addition, this cave was filled with extremely energetic mushrooms. Eating these mushrooms led to an unexpected change. Minerals and natural radioactivity stored in the mushrooms led to some specific DNA mutations ! Metal elements such as Mithril (Mi 119) get fixed in the dwarf DNA and harden their bones. With these mutations, dwarfs became stronger than ever, able to take some serious hits without getting permanently injuried.

Haversting the ressources of their cave, they became talented smiths. One day, strong enought to face it, they managed to kill the threat and began their long ascension to the “Surface”. When they reached this place their myths were talking about, they found a race called human and they didn’t have nothing in common with them as they were tall and very frail…

For the beards, you have to ask to dwarf ladies why they found them so sexy that they can't resist it...

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    $\begingroup$ I considered something similar, but remembered that something similar happened to the Falmers too (Elder Scrolls), and they don't look anything like dwarves (plus, the Falmers make more sense, genetics wise). $\endgroup$ – Foolish Jul 31 '18 at 9:46
  • $\begingroup$ @Foolish I edited my answer to explain why the dwarf evolved as dwarf and not as Falmers. $\endgroup$ – Freedomjail Jul 31 '18 at 11:15

Think of it in terms of animals. Humans came from arboreal, then grasslands-focused stock, so lankiness helped in brachiation and later, in spotting predators/prey over the grasses and chasing/fleeing over open terrain.

Dwarves live in tunnels. What common characteristics do underground/semi-underground mammals have? Broad forepaws for digging, relatively stocky for their size with a powerful core (think badgers/moles/voles), as their digging is more about sheer muscle than velocity/leverage. Relying on vibration/smell over sight, and valuing what they find in their tunnels (minerals, gems) for trade and culture, and what grows underground (tubers/mushrooms) for food and alcohol.


Let's look at it from a evolutionary point of view. Humans have evolved from "apes" in the savana regions of the world. We have then travelled to the rest of the world and developed to different races/skin pigmentation/whateva'h.

Lets say that dwarves and humans have a common ancestor ape but the two "tribes" of apes migrated into different territories before humans became humans and dwarves became dwarves.

Dwarve-apes could migrate into terrains where the was a lot of predators on surface but the caves and "underground" was pretty safe. Then those apes that stayed as in the caves would survive and give their offspring their genes. They could even start to eat worms/plants/animals that lived underground and start digging tunnels to find more food and create more space as the population grew bigger. With big population comes war, with war comes weapons. As the resources underground are pretty scare there were many conflicts in the dwarvean world, thus the cult of axe and warriors. War is costly, you need weapons, food and logistics. Gold, gemes and other things are valued by humans, elves and others, thus giving dwarves a reason to mine them. They could as well like gold them self.


For this speciation to happen, there are two things that are not true in our own real world, but which will happen to be the biological truth in your world:

  • Women in some region choose their sexual partners based solely and exclusively on penis size. Humans in general don't do it - when they do, it's more likely personal preference. But some animals choose their partners thus, leading to things like the great hooked squid, whose penis is as large as himself.

  • The L rule is true:

The L rule

If you catch my meaning.

As to why they are so stocky, they pack the same mass in a smaller chassis. In the immortalized words of Sir Mix-a-Lot:

Thirty six, twenty four, thirty six
Ha ha, only if she's 5'3"


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