Defining biological taxa with GURPS

[Michael Thayne]

I've been thinking about trying to design alien life with GURPS, and it occurred to me that if you're going for a high-verisimilitude setting, you'd really want each of your alien worlds to have its own "tree of life" and system of taxonomy. As a practice run for doing that, I thought it might be helpful to define Earth's major animal taxa in GURPS terms. It would look something like this:

• Fish: Generally have the Ichthyoid meta-trait and the 0-point version of Doesn't Breathe (Gills). Amphibious fish have the 10-point version of Doesn't Breathe (Gills) instead. (I'm unclear on whether any amphibious fish move well enough on land to qualify for the actual Amphibious advantage.) Most probably have the disadvantage Cold-Blooded, but fish adapted to extreme low temperatures won't have it. The Scales perk is standard.
• Amphibians: Adults generally have the Quadruped meta-trait and Doesn't Breathe (Oxygen Absorption). Most (all?) have the disadvantage Cold-Blooded. Amphibians don't usually have special perks for outer coverings.
• Reptiles: Most have the Quadruped meta-trait, but some replace it with Vermiform. Most (all?) have the disadvantage Cold-Blooded. Some are excellent swimmers and qualify for Amphibious and perhaps a few levels of Breath Holding (but never Doesn't Breathe). The Scales perk is standard.
• Birds: All birds have No Fine Manipulators, and most (but not all) have Flight. They never have the disadvantage Cold-Blooded. Penguins are excellent swimmers, and qualify for Amphibious and perhaps a few levels of Breath Holding, but never Doesn't Breathe. The Feathers perk is standard.
• Mammals: Mammals stereo-typically have the Quadruped meta-trait. A wide variety of other morphologies are possible, but never Vermiform. They never have Cold-Blooded. Some have the Ichthyoid meta-trait, which is often accompanied by Doesn't Breathe (Oxygen Storage), but never Doesn't Breathe (Gills). Their total number of arms, legs, and wings never exceeds four, but in some cases an exceptionally dexterous tail or even nose might count as a fifth "limb" in game terms. The Fur perk is common but not universal.
• Arthropods: ???
• Mollusks: ???
• ???

Note the ??? for invertebrates, which I'm too lazy to fill out right now. Suggestions on filling in the invertebrates would be greatly appreciated. Note also that this exercise only makes sense for taxa with members that weigh about 1 lb. or so as adults, otherwise they're going to be too small to even rate ST 1 in GURPS terms, and make more sense to handle as something other than characters (perhaps swarms, if they're going to be attacking the PCs).

[whswhs]

I disagree about birds and NFM. Consider the elaborate nests that some birds weave, or the stages erected by bowerbirds. Any bird with good grasping ability with its feet has Foot Manipulators, and parrots, at least, have their beaks as a short Extra Arm.

More generally, it looks as if you're doing something more like folk taxonomy (with its classes of beasts, birds, snakes, fish, and wugs), or maybe Linnean taxonomy, than anything post-1900. And there's nothing wrong with that as such; GURPS relies on folk taxa for many purposes. But that approach is going to be really hard to integrate with any kind of evolutionary one. If I wanted to make up evolutionary trees I'd base them on present-day taxonomy, for which there are many online sources, and hold off on assigning GURPS traits till I had conceptualized individual species.

Now, you're quite right about many species being so small that they could play a meaningful role only a members of swarms. GURPS Template Toolkit has more detailed rules for this. But those extremely small lifeforms will make up most of any realistic evolutionary tree.

[Phantasm]

I go by the Aristotlean taxonomy in my fantasy setting, plus an addition:

Sponges - soft very primitive and generally immobile invertebrates, such as sponges and anemones; also includes jellyfish

Slugs - most molluscs and other soft generally mobile invertebrates that lack limbs, such as slugs, snails, leeches, earthworms, tapeworms, etc.

Cephelopodes - invertebrates that possess limbs and lack skeletons, exo- or endo-; includes squids, octopuses, and cuttlefish

Arthropods - all legged invertebrates with a hard exoskeleton

Fish - cold-blooded vertebrates that breathe water, includes sharks

Reptiles - cold-blooded vertebrate air-breathers with skin or scales; amphibians, lizards, crocodillians, and snakes

Birds - warm-blooded vertebrate air-breathers with feathers

Mammals - warm-blooded vertebrate air-breathers with skin, fur, or scales that give birth to live young (note: platypuses and spiny echidnas are unknown in the world)


My addition:

Dinosaurs - warm-blooded vertebrate air-breathers with skin or scales that lay eggs


I also have Hybrids for things that are clearly "a (bored) wizard or sorcerer did it": pegasi, pegadactyls, gryphons, hippogriffs, etc.

[Michael Thayne]

Originally Posted by whswhs

More generally, it looks as if you're doing something more like folk taxonomy (with its classes of beasts, birds, snakes, fish, and wugs), or maybe Linnean taxonomy, than anything post-1900.

What makes you say this? I realize I've got some paraphyletic groups in my taxonomy, but insistence on phylogenic taxonomy became the norm only relatively recently, much more recently than circa 1900.

[Rupert]

Originally Posted by Phantasm

Fish - cold-blooded vertebrates that breathe water, includes sharks

And number of fish species (both shark and bony fish) are not 'cold-blooded' in either the common language meaning or GURPS' meaning.

Dinosaurs - warm-blooded vertebrate air-breathers with skin or scales that lay eggs

What if some dinosaurs gave live birth, just as some reptiles and fish do?

[whswhs]

Originally Posted by Michael Thayne

What makes you say this? I realize I've got some paraphyletic groups in my taxonomy, but insistence on phylogenic taxonomy became the norm only relatively recently, much more recently than circa 1900.

Insistence, maybe. But the project of classifying according to common ancestry emerged fairly directly from Darwin's work, and Ernst Haeckel was working along those lines by the late 19th century.

But I'm not actually commenting or you (stated or inferred) methodology. I'm making a comment purely on the stylistic impression your list of taxa gives me: in beteeen Linnaeus's classes of Mammalia, Aves, Amphibia, Pisces, Insects, and Vermes, and Cuvier's embranchements of Vertebrata, Mollusca, Articulata, and Radiata. Nothing like even Haeckel, let alone the bio texts of the sixties or the sometimes radical reshuffling emerging from cladistics and gene sequencing.

All of the latter were products of evolutionary thinking; the former were not and I doubt they can be made compatible with it, which it sounds as if you would like to do.

[RyanW]

Originally Posted by Rupert

What if some dinosaurs gave live birth, just as some reptiles and fish do?

They've recently discovered a fossil of an aquatic reptile which died with baby on board. While it is not a true dinosaur, is the first archosaur now known to give live birth.

[Phantasm]

Originally Posted by Rupert

And number of fish species (both shark and bony fish) are not 'cold-blooded' in either the common language meaning or GURPS' meaning.

What if some dinosaurs gave live birth, just as some reptiles and fish do?

It's not perfect, I admit. Reality does not like being nice and simplistic. Fantasy settings, at least, can be made "if the critter is marked 'Dinosaur' rather than 'Reptile' or 'Mammal', then the Control Dinosaur and Repel Dinosaur spells will affect it".

[Anthony]

Unfortunately, biological taxa are (mostly*) not defined by structural similarities, they're defined by evolutionary links. Thus, you can wind up with very similar creatures that are a long distanced apart by taxonomy.

*the exception is reptiles, which should properly either be split or include birds.

[Phantasm]

Yeah. There's three basic taxonomy structures: Aristotlean, Linnaean, and Modern. Linnaean built upon Aristotlean with what was learned about biology between Classical Greek times and the 1700s, and Modern builds upon Linnaean taxonomy with what we've learned since then with genetics.

As I stated, in my own setting I use the Aristotlean breakdown, with some changes to account for extant non-feathered dinosaurs. (In particular, my "Slugs" is by even Linnaean terms not correct, and the molluscs in "Slugs" should by all rights include the "Squids".) I wouldn't use it for a modern setup. (By all rights, most DF Oozes are likely closely related to RL slime molds....)