Body parts functions and "mutation paths" ?

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White parrot
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Body parts functions and "mutation paths" ?

Post by White parrot » Thu Oct 24, 2013 10:57 pm

In this old post, Quasar envisions that the bare minimum of body parts could be done by "starting from a simple design and branching out, letting the part design reflect it’s statistics rather than working out the statistics based on the part design". That is, imagining the stats modification parts of a given category can always undergo and associating a style guideline for each of those way ; then using an ancestral part as the root of a tree that branches out by having each new part undergoing a new level of the standard diversification.

It got me thinking. In the sketch, old_Quasar lists the relevant stats of a foot as stamina, speed and damage (one day we'll add swimming speed etc. :P ) ; what could we find as major stats influenced by other body parts ?



About tails : MrKyurem and AnarchCassius noticed that, well, they currently don't do much. They mention equilibrium (of utmost importance !), defense (/offense) and thermic regulation (not sure of this one, since changing the dimensions of the tail should do the trick without needing new design) as factors susceptible do modify a tail's anatomy. I'd add swimming and flying speed (agility if implemented ?), maybe climbing, to this list once these will be in.

Hands, for their parts, can for now almost only be used for damage : other potential roles in non-walking locomotion are currently postponed. Even by adding their potential "prehensility" (dexterity if we want to make it a continuum) that could enable to take food out of reach for the neck, not a lot of variations can be imagined, which I guess is why hands are rare in the BPVCT suggestion topic -as they are in Nature !


Notice how those relevant stats are more or less the same that come back every time. Cassius said about tails : "It could be treated like another limb really." ; and indeed, limbs share most of the same functionality, making the repartition of stats among them a bit contingent.

By the way : I'm for each foot having an immediatly corresponding hand, from where it could begin to specialize free from walking constraints, so as to avoid discontinuity when a quadruped become biped. It is somehow aesthetic : I'd like sudden bipeds to brandish their "hands" like they learned how to make the best of them, not as zombies with feet on their wrists. For example, a hoof would have a subtly different design showing that it is now wielded as a dangerous claw that is only worn out against the skull of foolish rivals, rather than a stupid, out-of-place hoof.
And/or.
Creatures could have limb tips usually used as foot, but of which they can raise one to use as a hand (/claw etc.). Some animals, like bears or gorilla, blend the distinction between hands and feet specifically because they can freely use their front limbs (could be their hind or middle limbs in Species !) as either.


The matter is a lot more complicated when we talk about heads : they are a lot more diverse in Nature, and it's strictly speaking impossible to resume their diversity in a little "stats tree" that makes sense. That being said, I'll try anyway, since it could be an inspiration for the type of heads we'll have to put in vanilla.
What follows will be a bit subjective. ^^'


It looks like a head is mainly a mobile support for the front of the digestive tract (da mouth), with a lot of sensory organs (assume I means something that generic each time I speak of eyes or vision) and a nervous centre. The whole shebang is systematically, when it exists, on the front of the animal.
My guess is that the development of a "front" in the first place results from a specialization in movement : since turning is rather easy, animals can gain a speed advantage by sacrificing the ability to move in any direction and focusing on their favourite axis. Accordingly, fastest animals are bilateral. It's better if the mouth is in the front, because this way it can easily snap at organic matter (as can attest anyone who actually tried to play Spore :twisted: ) ; sensory organs tend to congregate on the front so that the creatures see where it goes and what it is doing with its frontal mouth. Then, nervous tissue follow the sensory apparatus and ends up close.
Why did I expose this theory of mine ? Because there are holes in it ! Nature doesn't care about what is "optimal" in a vacuum, and a lot of animals don't follow this "royal road". Flies have a distributed nervous system and taste with their feet.
The question I wanted you to ask yourself is : "What is a head ?".
I think the answer is "a mouth". Most invertebrates have a more distributed nervous system than us, so this is not a criteria; and sensory organs could very well transfer themselves on prehensile front limbs rather than the mouth (noticed that Quasar ? That means I support the placement of eyes in other places than the head !), the priority being that the animal can perceive what its in front of him (in Species terms, maybe a creature instinctively restricts its moves when its current speed would get it in an unknown zone faster than it can react ; and seeing a food source boost the ability to use it correctly).

Consequently, I'll consider that the reservation of space for eyes and brain in the skull is somewhat contingent, and that the mutation map of the heads should focus on the diversification of the mouths.


The mouth is essentially an extension of the digestive tract specialized in two things : catching food/making it available and beginning digestion.
The first part implies extensions to reach the food sooner when arms can't do that (long and wide jaws, tongue, tentacles) while minimizing the air drag to gain in speed (prevalent in water, where fish create vacuum to suck in their prey or have thin jaws), and often the ability to defeat the food's defences : killing preys, rupturing shells, keeping hold of a slippery thing ; that is, mainly damage. Nuts would need to be cracked to be feasted upon, piercing damages can hold a prey or help suck its blood/sap -more cost effective than licking the blood flowing on the ground ... Living animals could have different resistance according to their type of defence.
On the other hand, predigestion include everything that the stomach (or equivalent) could do without, but that ease its job, such as mastication and tearing the prey item to pieces before swallowing.
And as you can imagine, the differences in prey item -flat leaves, hard nuts, tender meat- means that the solutions developed to catch and "defeat" are quite various. Meat can be hold with pointy teeth and cut with sharp ones ; leaves/grass eaters rake their food inside, and need a mix of sharp and grinding teeth to tame this silicated food ; hard food must be thoroughly ground, filterers have complex dewlaps, suckers have a proboscis ...

Hence, the main stats influencing the evolution of mouths are damage (often a part of obtaining a meal) and "eating rate" (not actually the speed of eating ... :? rather the quantity of nutrients extracted with each bite)(reflecting the ability to make nutrients more available for the rest of the digestive system) by diet.

Notice how limbs can help in almost all the cases ; actually, that's why the mouth of arthropod is mainly made of limbs pushed toward the throat. The differences in property between mouths and hands are sometime subtle : the limbs can sometime catch the food, tear it apart and bring it to the throat without the "strict mouth" having to specialize in any way.

Finally, can we make a correspondence between the stats of the mouth and its appearance ?
Well, the different natures of diet make it difficult to be general. The tree I propose instead is more focused on morphology ...
The first mouth is a naked throat, à la Primus specium, but with a generous number of attachment sites around it, susceptible to bear flexible (tentacles, tongues) or hard (jaws, mandibles) appendages, on which teeth can then grow : canine-like for piercing damage, molar-like for grinding, baleen-like for filtering etc. The appendages themselves would help with the eating rate (the hard ones sacrifice a bit of it for added bite damages), while each kind of teeth would have a different effect on this rate depending on the diet on which it is used ; and they would often help with damage, in different ways.
A single appendage could support one big tooth, from one to four successive types of teeth, or nothing. Ideally, the position in the mouth could have a role, with the more external tooth being more efficient as weapons but less as masticating help ...
Appendages and their tooth would be more efficient if they have an appendage on the opposite side on which to bear.

At this point we have more or less complex radula around the throat ; maybe two successive appendages could fuse to make a larger surface with a few rows of tooth, so as to make crocodiles possible. The ability to entirely close a mouth eliminating the risk of drooling food, each appendage would boost the eating rate, especially when fused ; this would be of tremendous use for liquivores, whose diet gain no benefit whatsoever from teeth, and which would gain from reducing their mouth to a tube.
Or maybe some appendages could be small limbs, like in insects, whose dexterity could compensate the drooling by snatching pieces of food to throw them back into the mouth or the throat ...



Okay, not all points are clear in my head or in this post, but it's getting late here and I've put the principal ideas :
- considering the stats used by parts could help design/choose new ones ;
- eyes could be put anywhere, but be more useful on the front (whatever the means) ;
- heads development is friggin' difficult to automatize. ^^"


Whatdayathink ?
Last edited by White parrot on Thu Oct 24, 2013 11:53 pm, edited 1 time in total.
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Re: Body parts functions and "mutation paths" ?

Post by AngerDomeAble » Thu Oct 24, 2013 11:24 pm

I fully support this endeavor and hope to see more in the future, also what do you think about something like a ant antenna?
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Re: Body parts functions and "mutation paths" ?

Post by White parrot » Thu Oct 24, 2013 11:35 pm

Let's see ... Antennae appear to be polyvalent sensory organs, so I'd treat them as eyes. :)

EDIT : it appears that baleens can be used for swimming. Who would have thought ?
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Re: Body parts functions and "mutation paths" ?

Post by AnarchCassius » Fri Oct 25, 2013 12:08 am

I agree with most of that. Particularly the mouth logic.

This leads to the gut itself (pun not originally intended). As you note many invertebrates have more simple digestive, repository and circulatory systems. Cnidarians and flatworms don't have a specialized anus even. How the creature internally distributes nutrients is also important.

Fast forwarding evolutionarily the largest known land animals were sauropods and they may possibly have even exceeded the blue whale in length, http://en.wikipedia.org/wiki/Amphicoelias_fragillimus. While I don't doubt the bones were real I have to wonder if the creature's proportions really scaled the same compared to it's smaller kin. There's also the fact that blue whale is still more massive than the estimates for any sauropod. The blue whale is in fact the heaviest animal ever known to have existed, so it's pretty cool that they are around when we are.

Also fairly big: elephants. What do these things have in common? Why did the sauropods get so big? One theory is poor diet. Having a huge gut means you can specialize it into a massive series of fermentation chambers. All of these animals eat a lot of questionably nutritious food and make the most of it. It also digests quite slowly.

So this maybe isn't as dramatic as the external stuff but it's something to bear in mind as chemistry is developed.

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Re: Body parts functions and "mutation paths" ?

Post by Quasar » Fri Oct 25, 2013 2:37 am

My guess is that the development of a "front" in the first place results from a specialization in movement : since turning is rather easy, animals can gain a speed advantage by sacrificing the ability to move in any direction and focusing on their favourite axis.

Actually, from memory, I think you've got this the wrong way around. A "front" didn't develop because creature's needed to become faster: creature's become faster because they developed a front.

The reason the forward axis developed in the first place because creatures need to take genetic shortcuts to make robust, large-scale structures. Obviously a large creature's DNA can't code for every cell individually: such a creature would be practically incapable of adapting to environmental changes. So they had to re-use genetic patterns.

Symmetry (radial or bilateral) is one such method of reuse, allowing a creature to encode just one side of the object. Since all symmetrical objects naturally have a 'front' and a 'back', symmetrical organisms could take advantage of this to develop mobility.

An alternative method of genetic re-use is fractals: making the same structure at different scales, with the smaller versions attached to the larger ones. A fractal creature wouldn't have a front or a back, so they would find it hard to develop non-random mobility and would have to find another niche. And lest you think I'm talking about something hypothetical and alien, fractal organisms have been wildly successful, and include the largest and oldest organisms here on earth. Plants.

Don't mind my nitpicking, I'm still digesting everything else you wrote... and to fend off potential topic derailment, non-bilateral creature forms have one of the lowest benefit-to-cost ratio's on my ideas list, so won't be happening any time soon.

...

For 'link' items like tails, limbs and necks, I'd think the dominant selection pressure is going to be mobility. Reach, coupled with strength, affects where and with how much momentum you can put whatever's on the end of your appendage.

This has a lot of effects, from sensory (a creature that can turn her head can do a better 'area scan' than one that can't), through offensive and predatory (violence!), to dexterity for climbing, grasping and perching (a flexible limb can compensate better for balance fluctuations than a non-flexible one).

Of course, 'mobility' isn't a simple linear value, either. We humans can turn our head through 270 degrees if we need to, but we've only got about 10cm of lateral movement. Meanwhile, it's doubtful a sauropod was capable of turning it's head without undergoing a huge amount of lateral movement.

Aaah complexity how I love thee.

...

More random thoughts...

You're right that the head types are basically mouths. The reason they also encompass skull shape is that it's difficult to get a strict mouthpiece to fit well with another object: it's too easy to end up with the other surface visible at the back of the mouth. It's possible to see this in species with the neck piece often appearing in some of the deeper maws.

Luckily, static head models are tiny memory-wise: a tenth of the size of an animated limb, and not even a 50th the size of a body covering. They still take work to create, but we can add a couple hundred of them without a noticable change in performance or download size.

We do plan to increase the variety of facial features, though, so the creature's will probably only get more surreal from here. We already have several categories implemented, including graspers, plates and humps, and just lack the assets for them.

And yes, I do want to turn 'facial features' into just 'features', but engine complexities and time constraints have made things difficult so far. Hopefully the current cleanup will make it easier.

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Re: Body parts functions and "mutation paths" ?

Post by sylverone » Fri Oct 25, 2013 3:41 am

Quasar wrote:And yes, I do want to turn 'facial features' into just 'features', but engine complexities and time constraints have made things difficult so far. Hopefully the current cleanup will make it easier.
We're rootin' for ya! ;)

This is some very interesting discussion. I can't think of anything to add at the moment. :)

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Re: Body parts functions and "mutation paths" ?

Post by White parrot » Mon Nov 04, 2013 11:49 pm

AnarchCassisus wrote:This leads to the gut itself (pun not originally intended)
Yep', I think most of the dietary stats of a creature will end up determined by its metabolism, once it's in. To be honest, it's one of my bad points, so I'm kinda curious about what it will do ...
Quasar wrote:Actually, from memory, I think you've got this the wrong way around. [snip]
Well, my bad. :oops: We learn something new every day ! :P



Okay, I just took a look at insects and Cheliceratesmouthparts for real this time ; my impression is that at most, animals have a way to pre-treat food (be it chewing jaws, powerful acid, even nothing if the food is easy to digest for them in the first place), a way to move food around (keeping it in the chewing zone, then moving it toward the throat) (tongue, articulated appendages ... being able to create a vacuum to suck in ...), and a way to keep food in during pre-treatment (a "floor of the mouth", the ability to entirely close the mouth while chewing, MOARE tentacles ...).
Also of note is the sheer power of convergence (baleen exists both as vertebrate teeth and echinoderm "pinnules", hummingbirds and bees have a nectar-licking tongue ...) and exaptation (everything that can hurt will be used as a dedicated weapon by something, mouths will be used to communicate by sound or colors ...).

These considerations may further help designate simplistic but coherent mutation paths ...
On this subject, I wrote that their variability makes it difficult to "automatize" the process of creation, but that's actually a stupid thought : stats-based mutation paths are only a design aid for Quasar and Jade (don't forget this member of the team !), who are apt to chose the more interesting concepts to focus on. We don't have to mathematically determine every single possible arrangement of the mouthparts : we just need a representative panel of striking looks from Earth and realistic fiction, and elaborate intermediate steps and ancestors to allow the evolution to work.
In brief, pondering stats and functionality should not be the design process anyway, but rather an indicator of unexploited design space. (As in : we don't have a hurty-killy tail yet. Go forth, my minions, bring me back a killer tail in my newer BPVCT !)



EDIT : by the way :
Quasar wrote:Symmetry (radial or bilateral) is one such method of reuse, allowing a creature to encode just one side of the object. Since all symmetrical objects naturally have a 'front' and a 'back', symmetrical organisms could take advantage of this to develop mobility.
could we use a metamerism system to allow for the legs to occasionally evolve together, instead of independently ?




EDIT : you know what, I changed my mind about feet.
Not sure if it hasn't been suggested elsewhere, but ...
Feet and hands could be one and a single category (LimbExtremity ?), the superficial difference being that their location influence the ease with which the creature can use it as a hand or a feet.
Let's say such a limbtip is used for walking if and only if it reaches the ground in the natural position (we'll see about the other types of locomotion when we'll come to that ^^"). Even then, any pair of limb can be used to attack or to catch ; if it is also used to support the body, the creature simply balance itself on one foot and use the other as a hand. A naturally "elevated" pair of limbtips ("hands") doesn't contribute to walk, but, being free from its support role, can alternate more quickly between its limb, effectively upping attack speed (or something) compared to a leg pair.
A "floating" creature (swimming, jumping, flying ; temporarily suspended in a fluid in any way) would obviously not support itself and so could use every pair of limbs as arms, hence the use of pouncing to make a double claw attack, for example.
Maybe some creature could "stand" to free up some of their limbs, at the price of their mobility ...

Note how distinguishing hands and feet only by their position means halving the number of limbtips to design, and automating the transition foot-hand each time the limb change conformation (they're the same now !) ... :twisted:
At this point, we shouldn't be surprised by anything nature does. She's like a meth addict whose drug-fueled rampages unfold in slow motion and span millions of years.
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Re: Body parts functions and "mutation paths" ?

Post by mw3modderman » Tue Nov 05, 2013 12:27 am

White parrot wrote:
AnarchCassisus wrote:This leads to the gut itself (pun not originally intended)
Yep', I think most of the dietary stats of a creature will end up determined by its metabolism, once it's in. To be honest, it's one of my bad points, so I'm kinda curious about what it will do ...
Quasar wrote:Actually, from memory, I think you've got this the wrong way around. [snip]
Well, my bad. :oops: We learn something new every day ! :P



Okay, I just took a look at insects and Cheliceratesmouthparts for real this time ; my impression is that at most, animals have a way to pre-treat food (be it chewing jaws, powerful acid, even nothing if the food is easy to digest for them in the first place), a way to move food around (keeping it in the chewing zone, then moving it toward the throat) (tongue, articulated appendages ... being able to create a vacuum to suck in ...), and a way to keep food in during pre-treatment (a "floor of the mouth", the ability to entirely close the mouth while chewing, MOARE tentacles ...).
Also of note is the sheer power of convergence (baleen exists both as vertebrate teeth and echinoderm "pinnules", hummingbirds and bees have a nectar-licking tongue ...) and exaptation (everything that can hurt will be used as a dedicated weapon by something, mouths will be used to communicate by sound or colors ...).

These considerations may further help designate simplistic but coherent mutation paths ...
On this subject, I wrote that their variability makes it difficult to "automatize" the process of creation, but that's actually a stupid thought : stats-based mutation paths are only a design aid for Quasar and Jade (don't forget this member of the team !), who are apt to chose the more interesting concepts to focus on. We don't have to mathematically determine every single possible arrangement of the mouthparts : we just need a representative panel of striking looks from Earth and realistic fiction, and elaborate intermediate steps and ancestors to allow the evolution to work.
In brief, pondering stats and functionality should not be the design process anyway, but rather an indicator of unexploited design space. (As in : we don't have a hurty-killy tail yet. Go forth, my minions, bring me back a killer tail in my newer BPVCT !)



EDIT : by the way :
Quasar wrote:Symmetry (radial or bilateral) is one such method of reuse, allowing a creature to encode just one side of the object. Since all symmetrical objects naturally have a 'front' and a 'back', symmetrical organisms could take advantage of this to develop mobility.
could we use a metamerism system to allow for the legs to occasionally evolve together, instead of independently ?




EDIT : you know what, I changed my mind about feet.
Not sure if it hasn't been suggested elsewhere, but ...
Feet and hands could be one and a single category (LimbExtremity ?), the superficial difference being that their location influence the ease with which the creature can use it as a hand or a feet.
Let's say such a limbtip is used for walking if and only if it reaches the ground in the natural position (we'll see about the other types of locomotion when we'll come to that ^^"). Even then, any pair of limb can be used to attack or to catch ; if it is also used to support the body, the creature simply balance itself on one foot and use the other as a hand. A naturally "elevated" pair of limbtips ("hands") doesn't contribute to walk, but, being free from its support role, can alternate more quickly between its limb, effectively upping attack speed (or something) compared to a leg pair.
A "floating" creature (swimming, jumping, flying ; temporarily suspended in a fluid in any way) would obviously not support itself and so could use every pair of limbs as arms, hence the use of pouncing to make a double claw attack, for example.
Maybe some creature could "stand" to free up some of their limbs, at the price of their mobility ...

Note how distinguishing hands and feet only by their position means halving the number of limbtips to design, and automating the transition foot-hand each time the limb change conformation (they're the same now !) ... :twisted:
so land creatures are going to evolve into sea creatures?? backwards much? I really have no idea what you said, other than something related to such.

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Re: Body parts functions and "mutation paths" ?

Post by AnarchCassius » Tue Nov 05, 2013 12:43 am

so land creatures are going to evolve into sea creatures?? backwards much? I really have no idea what you said, other than something related to such.
Yes and no. Right now we start with land lampreys or something and neither flight nor diving is supported. Creatures can evolve to swim at the surface like a Stellar's Sea Cow and thus "return" to the water from which they hypothetically came much like... well a Stellar's Sea Cow.

When diving and flight go in I'm hoping our base creature may more resemeble a lungfish and have better innate swimming. It's partially an engine issue.

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Re: Body parts functions and "mutation paths" ?

Post by mw3modderman » Tue Nov 05, 2013 2:29 am

AnarchCassius wrote:
so land creatures are going to evolve into sea creatures?? backwards much? I really have no idea what you said, other than something related to such.
Yes and no. Right now we start with land lampreys or something and neither flight nor diving is supported. Creatures can evolve to swim at the surface like a Stellar's Sea Cow and thus "return" to the water from which they hypothetically came much like... well a Stellar's Sea Cow.

When diving and flight go in I'm hoping our base creature may more resemeble a lungfish and have better innate swimming. It's partially an engine issue.
Wouldn't that still be backwards of evolutionary history, I thought sea creatures were the first of large organisms.

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