Science In My Fiction

So far I’ve written about worldbuilding science for laying out entire worlds, and some unusual types of habitats. Most fiction doesn’t take place on a whole planet, or somewhere truly odd, it happens in a smaller region of an ordinary world. Even for a nearly-normal place, there are biological principles that the SFF author could use to make a locale distinctive and still plausible.

Island biogeography is one of my favorite, combining as it does migration and evolution and frequently-bizarre plants and animals.

Take an isolated habitat like an island. It might start with plants and animals on it, but once the island becomes separated from the original home ranges of those species they can’t mix with the larger population.

New species can come in through immigration, but the more isolated the island is the fewer kinds of species can get there. Isolation is relative: terrestrial mammals are a lot easier to stop than birds or marine mammals.

Original species or newly-introduced species can also go extinct on the island even if they are thriving elsewhere. Since new individuals can’t easily get there, the island populations are on their own. A small population can go extinct just by chance. Habitat change over time can also force species “off the island.”

The “island” doesn’t have to be land in the middle of an ocean, either. A lake in the middle of a continent might be an isolated habitat if you’re interested in fish. A mountaintop can be an “island” if the species can’t climb down one mountain and back up the next. Isolation is relative.

The size of the island is important too. A larger island offers more habitats so it can support a larger number of different species. A larger island might be able to support larger populations of each species, making it less likely that an individual species would go extinct.

Now comes the fun part: closed habitat (more or less), limited types and/or numbers of species, limited or abundant resources. Let the natural selection begin!

New Zealand makes a great example of what can happen on isolated islands. New Zealand separated from Gondwanaland between 80 and 100 million years ago. It started out with plenty of plants and reptiles, but if any very early mammals were present they quickly died off. (The mammals didn’t start to become dominant until 65 million years ago.)

New Zealand still has the descendant species of some of reptiles that were already there, like the tuatara – the only surviving species in its entire family. All its cousins died off about 65 million years ago.

(via Wikipedia)

Birds could fly in, though it was a long trip. Without pesky mammals to eat eggs and compete for food, many of the bird species didn’t even need to fly once they settled in. Flying is an expensive skill, so it was entirely lost in some species. Because all of these birds evolved in isolation, they are found only on New Zealand. Many have gone extinct since European colonization: at least 43 species, or a third of the total number of birds.

(via Wikipedia)

The kiwi is a national symbol, but there were many more distinctive birds. The harpagornis, the largest eagle known to have ever existed, lived on the flightless birds like the moa, and died out not long after Maori settlement when the moa were hunted out.

Birds evolved to fill the roles that mammals would occupy in most other places. The largest known eagle (now extinct) lived on New Zealand.

(via Wikipedia)

Since New Zealand started out without mammals, only the species that could travel long distances through or over the ocean got there. There are plenty of aquatic mammals, like whales, dolphins, seals, and sea lions. These species are not isolated from their parent populations.

(via Wikipedia)

The only terrestrial mammals present on the island before humans arrived were three species of bats. The birds don’t fly, but the mammals do. Like the birds, the short-tailed bats adapted to the lack of ground mammals and evolved to crawl around on the ground as well as fly. They could tuck their wings away and scamper around like mice.

Once people started coming to New Zealand, another pathway for intentional and unintentional plant and animal introductions opened up. The Maori brought some species from 1250 or so, most notably the Polynesian rat and the domesticated dog.

After Europeans discovered the islands in 1769, they brought all sorts of animals: pigs for food, mice and rats accidentally, weasels and ferrets to catch the rats, possums for fur. These adaptable mammals have driven many of the native New Zealand species to extinction, and have threatened most of the rest. Conservation efforts are trying to reduce or eliminate these invaders. One such project led to the removal of 30 tons of dead possums from one of the smaller islands.

Back from science to fiction: I see all sorts of possibilities here. Some part of your created world could be isolated from the rest, and thus distinctive. One human colony or space ship could be isolated from the rest, allowing the humans and their attendant species to evolve in ways unlike the main human population. Or the entire human population could fragment into smaller isolated populations.

And what about accidental introductions, either by human settlers or alien visitors? What if we accidentally introduce rats to a space station? Or aliens introduce their scavenger species to London? What species go along with colonists, intentionally or accidentally, and what effects do those have on the native populations?

My brain is fizzing with ideas for alien ecosystems. I hope yours is too.

Recently I read an article on Cracked.com (Thanks to Roger Ebert for the link) titled “7 Animals That Are Evolving Right Before Our Eyes”. It’s a fascinating list, ranging all over the animal kingdom. (And before you make a crack – sorry, bad pun – about scientific accuracy from a comedy site, every item on the list has multiple sources cited and links provided.)

As I read the list, I noticed something a bit disturbing: Almost every animal mentioned is evolving (apparently) in response to the effects of humans on their habitat. Tuskless elephants are being born with greater frequency (most likely due to poaching of tusked elephants); Peppered moths apparently changed color to better hide from predators amidst the pollution of the Industrial Revolution; and some of Moscow’s stray dog population appears to have learned to ride the subway.

The one item that most gave me pause was the discovery of the Grolar bear – that’s a hybrid between Grizzly and Polar bears. Amazingly, in April 2010 one bear was killed by a native Inuvialuit hunter, and DNA tests confirmed that not only was it a grizzly/polar hybrid, it was 2nd generation – meaning unlike some other hybrids (like the mule), grolar bears are fertile. This means that, as the polar bears’ habitat melts from global warming, there may be more and more meetings between polars and grizzlies, resulting in more hybrids, which could continue to reproduce – creating a large population of grolar bears (or Brolar bears, as polar bears can also successfully mate with brown bears).

As Cracked pointed out, polar bears are carnivorous, while 80-90% of the grizzlies’ diet is plants. So by nature, polar bears tend to be more aggressive. And this means that a hybrid grolar could be, in essence, a highly aggressive carnivorous beast that’s better suited to warmer climates than its grizzly parent or grandparent.

It occurred to me to wonder whether our damaging the environment has led to the creation of a predator that will intrude on our territory before long. And that got me thinking: what other crazy or unexpected animals might our influence on the planet jumpstart into existence?

So let’s hear your theories! What animal will evolve in the near future as a result of our effect on the world that we’ll come to regret? And please be realistic – no matter how entertaining it sounds in theory, there will never be a sharktopus.

Species don’t exist in a vacuum. That is, if you go nearly anywhere on this planet, you’re not going to find just one form of life. You’re going to find several, all filling different niches and frequently interacting with each other. (I say nearly because I don’t know whether the extremophile bacteria in the Earth’s crust are one species or several. I’m betting there are a range of them in any given location, given how resilient and diverse life is.)

The most familiar relationship between species is probably that of predator and prey. There’s the lion and gazelle, the wolf and the caribou, the anteater and the ant. We’re familiar with parasitism too—one species feeding off another without killing them first. It’s as easy to cast Earth parasites as villains as it is to cast predators. Parasites are often widely known, affect humans, have historical impact, or get handy evil-sounding names. Examples of the first three categories are fleas, mosquitoes, intestinal worms, ringworm, lice, and insect-born diseases such as malaria. Examples of the last one include strangler figs, vampire bats, and the zombie ant fungi that have been in the news lately.

Stargate’s Goa’uld, Spider-man’s Venom, and the xenomorph from Alien are examples of fictional parasitic antagonists. There’s a list of other made-up parasites on Wikipedia, though it’s probably incomplete. That said, I think we could go further. I’m not sure I’ve seen a bio-apocalypse or bio-thriller with protozoa or insects as a vector, though I’ve seen them with bacteria and viruses. And we shouldn’t forget the parasites that don’t affect humans. Some insects, such as wasps, lay eggs in other animals. A number of vines choke the life out of their supporting plants. Who knows what other kinds of parasites might evolve on other planets? Or if an alien parasite could use the strangling or egg-seeding techniques on humans?

Discussion of parasites leads us into other types of symbiotic relationships. (Yes, parasitism is a form of symbiosis.) There’s mutualism, where both species benefit. There’s commensalism, where one species benefits and the other is neither helped nor harmed. There’s also amensalism, where one species inhibits or kills off another but isn’t affected itself. Penicillium mold does this with some bacteria, for instance, and some plants produce substances that kill off competing plant life.

Mutualism can involve trading resources (think of nitrogen-fixing bacteria in plants), trading a service for a resource (pollinators, remora and sharks, animals dispersing seeds), or trading services (clownfish and anemones, ants nesting in trees). Humans are in mutually beneficial relationships with the bacteria in their intestines, and with domesticated animals.

Examples of commensalism include the cattle egret, which feeds off the insects stirred up by grazing cattle; barnacles, which attach to animals and plants as well as rocks and ships; plants that use other plants for support, such as orchids or moss; and hermit crabs, which use shells as housing.

Of course, the plants, animals, fungi, protozoa, and bacteria that engage in symbiotic relationships continue to evolve. They become better parasites, or better killers of parasites, or better nitrogen producers, or better protectors of their symbiotes. They’ll change size or shape or color or biochemistry. A change in one often means a change in the other. Symbiotes may even suffer a disability if their counterpart is removed. Lichen wouldn’t even exist if you separated the fungi and algae that form it, and removing a symbiote from an ecosystem could cause a cascade of species deaths and ultimately destroy the ecosystem.

Some questions that may spark a story or two:

• What happens if you introduce an alien (let’s say, truly alien) species that becomes a parasite or other symbiote to a native organism?
• Could you bioengineer a lifeform to enter into a symbiotic relationship with a plant/animal that needed a boost? Could you turn parasitism into mutualism?
• Could you alter a symbiote’s genes to give it freedom? Would there ever be a circumstance where you’d want to do that?
• What if one intelligent species was oppressing its equally intelligent symbiote for, say, eating insects instead of plant matter or having a strange physiology?
• Since symbiotes tend to co-evolve, pick a possible resource or service that a species could provide, the crazier the better, then create a species that would make use of it. Remember that it will likely also be providing a service or resource for the other species. (E.g., a mollusk that feeds off electricity produced by electric eels; a plant that grows on a herbivore’s head and acts as a sound amplifier; an insect that cultivates a particular plant so that its eggs can hitch a ride on the seeds)

It occurred to me the other day that many fictional alien species conform to a small number of body plans: humanoid, insectoid, feline, robot, and reptilian. There’s a huge amount of creativity in appearances and cultures, admittedly, but most races out there fit one of those body plans. The Wikipedia list of fictional aliens is a good overview, for the above and other body plans, though it’s definitely not complete.

I realize there are reasons why most aliens are humanoid or nearly so. It’s easier to sympathize with something that looks human. It’s easier to conceive of aliens based on familiar Earth species. It’s easier to put make-up on an actor than to deal with CGI, or it was until recently. Still, why doesn’t more science fiction push the envelope? Why don’t we see more unusual body plans? It’s not as though we’d have to create entirely new physiologies, though we need those too. Earth has a whole host of creatures that have been underutilized in science fiction, including a few with proven intelligence.

Sharks, for instance, are ancient. They have cartilage instead of bone. They sense electricity and have an excellent sense of smell. They have problem-solving and social skills. There are documented cases of parthenogenesis. They’re built for predation and we’re already conditioned to cast them as villains.

Octopuses, corvids, parrots, and dolphins also have intelligence, or at least use tools and solve problems. Ravens can mimic sounds and have a wide range of calls, often for social purposes. Parrots are capable of communicating with humans. Dolphins have proto-language as well and are highly social. When was the last time you saw them (or parrots, or octopuses, or sharks) cast as aliens? Well, except for Hitchhiker’s Guide to the Galaxy…. Other possible species include: horseshoe crabs, trilobites, rabbits, elephants, slime molds, moss, bacterial hive-minds, and marsupials, including monotremes.

And as I mentioned above, we need more entirely new physiologies too. Species that don’t match up with the Earth life we’re familiar with, or even with our extremeophiles. If we make the environment first, the species second…

One possible environment, close to home: the diamond oceans of Uranus and Neptune. This would be a hot, high pressure place to live. There probably wouldn’t be a lot of gas mixed into the diamond, let alone oxygen, so either the aliens wouldn’t breathe, they’d use a system like photosynthesis where they’d break down carbon for energy, or they’d be like whales, surfacing to breathe hydrogen, helium, or methane (those being the abundant gases). The aliens would almost certainly be carbon-based, and would consume other carbon-based life for energy. They’d likely evolve something like fins or flagella to propel themselves. Maybe they’d use jet propulsion.

There’s no reason why these aliens couldn’t evolve intelligence or even civilization, though I doubt they’d achieve buildings as we know them, because short of building on the solid-diamond floes, there’d be nothing solid, and the caps probably wouldn’t be all that stable. I can see floating structures tethered together, however, provided the aliens had something to build with. Perhaps after millennia of them using these structures, they’d adapt to them, becoming more amphibious than aquatic or losing the flippers and gaining something more like hands. Or perhaps not.

I have no idea what first contact will look like when we make it. The realistic version, of us finding microbes on Mars or one of Jupiter’s moons, lacks a certain something, though I’ll be pleased when it happens. But wouldn’t it be great if we ran into alien blue jays or giant platypuses or sentient hammerhead sharks?

An earlier, rougher version of this essay was posted on my blog, Specnology.

On June 4, Peggy Kolm posted her article Red hills of distant planets. Prior to that date, one title proposed for the article was “The color of alien plants”. During a discussion about the article, the proposed title was misheard as “The color of alien pants“. And the idea for this article was born.

Really, what color would alien pants be? And for that matter, would they wear them at all? This isn’t to suggest that all aliens are exhibitionists: maybe they just don’t need clothing.

Human use of clothing dates back (most likely) between 100,000 and 500,000 years. Its main purpose (initially) was protection against environmental threats; as humans evolved and lost natural physical protections like body hair, we needed extra help surviving harsh weather and difficult terrain. Clothing has evolved along with us, growing more sophisticated as we have: sewing needles date back as far as 30,000 years; flax fibers are known to have existed 30,000 years ago; and there’s strong evidence that humans have been weaving for a good 10,000 years or more.

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In my previous post, I explored convergent evolution: when two different species, usually separated by distance, evolve a similar physical characteristic independently of each other. At the end of the post, I said that I would follow up with a post on the far more common divergent evolution.

Simply put, divergent evolution is when two groups of the same species evolve differently. The environments in which the groups live are the most common cause of divergent evolution – in other words, if two groups of the same species are separated into different environments, they will each evolve and adapt separately to fit the environment they’re in. Arguably the most famous example of divergent evolution is Darwin’s finches, which he described in On the Origin of Species:

“The inhabitants of the Cape de Verde Islands are related to those of Africa, like those of the Galapagos to America. I believe this grand fact can receive no sort of explanation on the ordinary view of independent creation; whereas on the view here maintained, it is obvious that the Galapagos Islands would be likely to receive colonists, whether by occasional means of transport or by formerly continuous land, from America; and the Cape de Verde Islands from Africa; and that such colonists would be liable to modification;—the principle of inheritance still betraying their original birthplace.”

- On the Origin of Species, Chapter XII: Geographical Distribution. Charles Darwin, 1859

The “inhabitants” Darwin refers to in the above passage are the variations of finches. (It’s interesting to note that, since Darwin was developing the very concept of evolution, he didn’t have a word for it to utilize – instead referring to it as “modification”.)

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Why is it that the most enduring, recognized form for aliens to take in our stories is “humanoid”? Walking upright, two legs, two arms, two eyes, etc. The most stereotypical term to refer to visiting aliens is “little green men“. Why do we so often assume that aliens will be so similar to us?

Part of it is undoubtedly because there is a comfort in familiarity; if they look kind of like us, they must be like us, right? (Conversely, we feel more confident when the bad, violent aliens look nothing like us.) A certain lack of imagination on the part of those who craft the stories also plays a role. And let’s not discount the practicality of putting a human actor in a roughly human-shaped costume.

But there’s actually a reasonable scientific justification for an alien life form to have a similar form to ours. It’s called convergent evolution.
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