Continuing where I left off, to better account for evolution in fantasy worlds, the most important step is to switch from top-down to bottom-up thinking. Sounds easy until you remember you're thinking of art, lit or marketing majors (or worse, video game designers) none of which are big on logic or have learned any science since tenth grade, and all of which probably have a massive god complex when it comes to finessing their babies into the exact perfect artistic (and profitable) vision that came to them last St. Andrews' day in a dream while on the toilet at a luxury expositional expo. This in fact makes fantasy storytelling particularly recalcitrant, playing god in a setting with actual gods, as "so the prophecy foretold!" melds perfectly with "this half-assed backstory sounded hella dramatic in my plot outline." It's not like the internet isn't peppered with such rants already, but if you're wondering why anyone would even bother with such speculation, I'll get to that at the end.
Remember: fantasy is a
top-down system where the rules are handed down by magical beings,
while SF is a bottom-up construction upon consistent (if imaginary) physical laws. SF
is evolution; F creationism.
However...
I
would be curious to see more settings (and to me, fantasy mostly means
game settings) bucking that trend, or at the very least doing a better
job of worldbuilding than slapping random species onto a random
landscape like pizza toppings. Besides, I already promised a post on
fantasy evolution
earlier this year when complaining about
Lord of the Rings Online idiotically drafting dwarf women into front line combat in the name of female
superiority and in defiance of Tolkien's well-reasoned dwarven
hyperprotectiveness toward their minimally fertile 1/3 female
population. Given I already touched on dimorphism (that's what she said)
back in 2017, I'll shelve sexual selection for some future date and widen the scope to general morphology/behavior.
Let's start with some basics:
Evolution, fundamentally, can be expressed tautologically: what lasts, lasts. (The devil's in the details.) Also, since the cell/body/colony does not get copied over via reproduction, it's genomes, genes or whatever gets reproduced generation by generation out-lasting each other by expressing more favorable proteins/cells/bodies/behaviors. Not a huge issue in works of fiction, until writers forget their creations would need to reproduce in order to continue existing as species or societies - see the dwarf example above. It also means that anything which interferes with reproduction is severely, severely, SEVERELY maladaptive, something to think about when you're designing all those noble, monkish space-elves who do nothing but write poetry and practice their katas all millennium long, but somehow manage to coexist with pod-people and sapient fungi. It doesn't take a war to get over-run and starved out by the numerically superior.
Also, something doesn't need DNA to evolve. If your robots or nature spirits make copies of themselves and each has minute differences in their programming/soul/WhateverMakesItTick then those which reproduce more successfully will compose more of the next generations, and so on until they replace the original stock. Saberhagen's Berserkers would long have replaced themselves with a version that doesn't expend resources and endanger itself by hunting down all life in the universe.
Aside from that, the general pattern is:
1) shit happens - random mutations in germ line (remember, if it's not passed down, it doesn't count)
2) shit gets cleaned up - natural selection (less adaptive traits reproduce less successfully and so do their bearers) (this is the part creationists like to ignore when scoffing at the idea of random chance producing complexity.)
Remember that even if a body part is not directly harmful or beneficial, it still imposes an energy (nutritional) cost on the organism growing and maintaining it. So please stop sticking all those redundant crests, spikes, limbs and feathers onto your fantasy races! Art majors, THIS MEANS YOU! ... "Dire" badger my dire ass. Remember that mutations pile on very gradually into recognizable features so if you want something to suddenly sprout wings in a single generation, you'll have to resort to an explicit "it's magic" dodge. (The mariner's gills in Waterworld were a real groaner.) Remember also that selection works in the present. Plants don't randomly start producing gigantic colorful flowers just in case bees might appear in ten million years. Exception: exaptation, where a feature you already have acquires a second use, like insulating feathers also aiding flight.
Selection is anything but random. The environment directly impacts which related organisms reproduce more successfully, and therefore how the overall population will look in a hundred or thousand generations. Which is actually good news for writers, because you get to start with a map! And you love maps, don't you, you Tolkien wannabe ha- aherhm, where was I... maps. You probably have a vague map in mind already. You know you want your heroic band of adventurers to cross some snowy mountains and some rivers, exactly one swamp and definitely an erupting volcano or seven along the way. You're already picturing both the boundless creaking taiga and the chokingly dense multicolored vines overwrapping the rainforest. Cool. Plate tectonics and erosion lie beyond my current scope, except to note it's one aspect Tolkien tended to be weak on, slapping mountain ranges perpendicular to each other and rivers flowing every which direction.
Figure out your landscape first, then start deciding where your heroes will encounter various creatures based on a few general rules of adaptation, starting with temperature gradients. (I won't bother citing them one by one, but I should note Wikipedia features a nice list of
biological rules)
- Cold environments favor warm-blooded creatures large enough to conserve heat. (Ice-snakes are weird.) Corollary: compact bodies conserve heat better, so cool it with the stilt-legged, bat-eared icewalkers. Even moose and reindeer are stockier than their tropical cousins.
- Reptiles are good at conserving water and require fewer nutrients, outcompeting mammals in hot deserts. Which is to say, there are other animals than camels in deserts. Look them up.
- "Amphibious" does not mean perfectly adapted to both environments. Keep in mind frog locomotion mainly gets them back in the water as fast as possible. Aquatics would have support and locomotion issues on land (see seals).
Please, no prancing mermaids. Also, long flowing hair is NOT
hydrodynamic.
- Cave dwellers might see better in dark but more likely favor other senses (see the famous blind cave _____) Goblins probably would not have amazing vision, and even if they're just nocturnal would likely be colorblind to increase light sensitivity (see bats.)
- Islands have a weird effect on body size, with large species getting smaller due to limited resources, and more often small species getting larger due to lack of predators. This would be an excellent way to work that cosmetic re-skin game designers love so much in a logical fashion... and one I never see used.
- Parasites tend to fit their host, both in size and intersecting life cycle. In fact, they closely co-evolve with their hosts over generations, to the point of strictly specializing (especially internal ones) in a few closely related species. Your heroes have nothing to fear from dragon tapeworms. This was one major plot hole in the original Alien movie, addressed in pathetically hamfisted fashion with Prometheus.
- Magnifiy that by orders of magnitude for anything which evolved in complete isolation (e.g. on different planets) and especially do not EVER talk about miraculously compatible alien genetics. DNA is not just a linear code, but produces and depends on a myriad scaffolds, chaperones, cofactors, regulators, markers and processes like tagging or splicing, not to mention the million convoluted signal cascades required for DNA to react to its extracellular environment, all of these developed in tandem between the existing template and iterative selective pressure over literally billions of generations. The odds of something which has never encountered either the same template or the same pressures spontaneously producing hybrid offspring are, statistically, nil! Nil squared! Nil to the tenth! Just... don't! If you want half-alien babies, you'd end up needing to genetically engineer some hopelessly wasteful monstrosity operating on two separate metabolisms at once (and they'd probably be sterile and poisoned by BOTH parents' native environments) to the point any intelligent species would give it up and opt for robots. Golems. Whatever. Sorry, didn't mean to get S all up in your F.
That brings us to the issue of divergent and convergent evolution.
Divergence usually results from separation. Half your elves go over the sea, dark hair randomly predominates in one population, light in the other. One side's taller, one side has longer pianist fingers. Cool, whatever. It can also result from specialization (as Larry Niven so memorably tried to portray in Ringworld) and this is where your handy-dandy map comes in. Do you have populations of elves living in plains/mountains/forests for tens of thousands of years before developing civilization? Give the plainsrunners long loping legs to cover long distances, and the tree-climbers shorter legs with prehensile toes, and the mountain-climbers partially hardened, hooflike foot soles and oversized lung capacity. Chesty elves. Hell, why not? We've tried every other kind.
Convergence generally results from different species adapting to the same necessity, and for fictional purposes largely concerns morphology. Limb shape is a famous example, as each medium strongly favors one or two modes of locomotion, so that even across hundreds of millions of years and distantly related clades, runners, swimmers and soarers will gradually develop legs, fins and wings independently of each other. What does this mean for fantasies set in alien landscapes? Well, if you create an environment of shattered floating islands over a bottomless void, everything from bugs to buffalo would need some way to cross those gaps, be it by flying, gliding, steering the islands, or clinging parasitically to flyers, shooting spores to the wind or ballistic seeds. If you set your adventure among the vertical trunk and branches of a world tree, then climbing adaptations (prehensile tails, low centers of gravity, gripping pads and claws) would predominate as would ways of taking advantage of the world-tree's sap, a world of squirrels, geckos, aphids and orchids.
Above all, remember everything must somehow acquire the energy and chemicals it needs to carry out its metabolic processes. Case-in-point: Herbert's sandworms. Leaving aside the question of whether their burrowing friction would glass the sand around them, no way in hell would they ever filter enough food from desert sand at their size to fuel such an energy-intensive method of travel, in direct contrast to their likely inspiration, baleen whales, which make use of buoyancy and currents. Even if it were possible, they'd get out-competed for food by smaller, more efficient burrowers. If you want a big impressive beast in your story (like dragons) first ask yourself: what does it eat? And does something else eat that better? Moby Dick ate giant squid... did Smaug eat giant flying squid at altitudes other flyers can't reach? This also goes for armies, with the classic question of how exactly the utterly barren Land o' Murder's provisioning all those tens to hundreds of thousands of indigenous orcs. How many Mordors' worth of farmland would it take to supply one Mordor's worth of orcs and trolls?
This brings us to behavior.
Try orcs. They live in close, overpopulated, hypersocial bands but act like Tasmanian devils or other infamously solitary, hyperaggressive beasts. They're basically locusts in a perpetual state of swarming, except swarming behavior is better interpreted as a terminal investment strategy, where an organism responds to drought, overpopulation, other scarcity or morbidity by investing its energy reserves in a massive reproductive / dispersal gamble. Inherently untenable, and functional only as such. Orc-like fantasy/SF races would work better if the author more carefully described a population boom/bust cycle and paid closer attention to the triggers which turn mundane pests into plagues. Note this carries far more plot-driving potential than the basic description of orc-types as "mean and many." To some degree, the idea that they coalesce as armies and pose major threats only under Bolg or Sauron-like leadership approaches this, but how much better would it get by tying it all together with physical and hormonal changes?
In a greater sense, while the
r/K distinction is less distinct than once thought, it still pays to think of your fantasy races in terms of their life histories relative to each other. Long-lived, slow-growing, slow-breeding elves which take a thousand years to repopulate would need stable environments, something Tolkien rather elegantly incorporated into those secretive, defensible elvish enclaves like Rivendell. Just randomly scattering around unexplored woods in vulnerable bands would open them up to disaster. Note, great apes are classic K-strategists, and humanoids would not spread easily through that standard-issue dramatic fantasy landscape constantly erupting with volcanoes and getting wiped out by manageddons and genocided by evil wizards at random intervals. You need to give your humanoids some breathing room for them to form believable societies.
Conversely, rapidly reproducing, short-lived, expansive species replenish their populations better after disaster but gradually fall prey to more careful, resilient competitors during stable periods. Klingons would probably live to thirty and have fifteen children each to offset their idiotic hyperaggressiveness.
Keep in mind environment shapes both biology and culture. Creatures adapted to constant Under-dark or the deep ocean, even if they can see, would probably not wax poetic about light/dark dichotomies like those of us subjected to circadian cycles; nor would they winter their discontent when they've never seen the passing of the seasons. Burrowing creatures would not have a "high" king like we arboreal descendants.
If you've had the patience to read this far, you might be growing a tad exasperated at my making a mountain out of a molehill. After all, it's freakin' fantasy, dude! It's like, magic! Unsure how something works? It's magic! A wizard did it!
Therein lies the problem. Magic is magical by contrast to the mundane. Make it mundane and kill its appeal. Don't gratuitously fabricate unicorn-fart-powered lightbulbs where "a candle" would fit your narrative purpose just as well. Just as you should do your homework for the fields of basic mechanics or sanitation so you don't need to resort to wheelbarrows or outhouses powered by pixie-dust, get some basic nature documentary understanding of biological principles so you don't need to magically explain why your rainforest's full of polar bears.
One common surprise expressed by younger audiences when finally getting around to reading Tolkien, the precursor of D&D or WoW, is just how little magic actually plays into his plot twists. The stories which created high fantasy are in fact low fantasy. Yeah, and that's why Middle-Earth is still the champ. Its author did his homework, and didn't resort to gratuitous, amateurish overstatement where a mere understanding of the world would fit more naturally. When Gandalf casts a "light" cantrip or Samwise tells a rope to un-knot itself, it actually comes across as magical!
I leave you with one last question to be addressed in the future: how would magic itself affect evolution?