Orcs - uplifted plants?

koz · Post by **koz** » Sat Feb 20, 2010 11:22 pm

I'm currently doing a bit of writing for my (very extensive) houserules, and I decided that both orcs and goblins are uplifted plants, with the idea that their green pigmentation is basically chlorophyll. Resultantly, they would essentially photosynthesize to supply their energy needs. Now, this raises a lot of questions my own research cannot satisfactorily answer.

1) Is it possible for a motile being the size of a humanoid of Medium size to have enough surface area to get enough energy to maintain vital processes via photosynthesis?

2) Plants, as I understand it, require nitrogen, which they take from the soil as ammonium compounds, as airborne nitrogen is extremely inert due to the triple-bonding of N2. Does that mean that a motile being would literally need to eat ammonium compounds for its continued growth? If so, what would the easiest way for a motile being to do that be?

3) If it is impossible for photosynthesis alone to sustain an orc, would they need to be photoheterotrophs? What kind of implications does this have for orcs and goblins in terms of their biology?

While these are very open-ended questions, I'm not a biologist, and thus, I find it very difficult to answer these questions. Any and all information you could give me on this subject in as plain an English as is possible would be great.

K · Post by K » Sat Feb 20, 2010 11:39 pm

1. No.

2. Urine.

3ish. Forcing orcs to be plants seems a little heavy-handed. I'd suggest some other backstory. Maybe copper oxide (whick is green) in their skin because they can't metabolize copper and that is an alternate way for them to get rid of it?

Considering that humans that can't metabolize copper and ingest it tend to be psychotics, it feels orcish.

RobbyPants · Post by **RobbyPants** » Sun Feb 21, 2010 1:20 am

I could be wrong on this (it's been 10 years since I took any Biology classes), but I thought one of the end products of photosynthesis is glucose. Glucose is use in respiration with oxygen to give energy to animals (basically, the two processes are mirrors of eachother).

Would it be possible to consider these orcs/goblins to be both plant and animal? If so, the photosynthesis could be used to help alleviate their need for food, and to get them through short periods without food.

I don't know. Maybe the concept of a part plant/part animal creature is too far fetched to consider.

Jilocasin · Post by **Jilocasin** » Sun Feb 21, 2010 2:17 am

The Green Sea Slug part plant, part animal.

Lokathor · Post by **Lokathor** » Sun Feb 21, 2010 2:27 am

I honestly don't think it's possible to come up with a creature too far fetched for DnD's world of magic.

koz · Post by **koz** » Sun Feb 21, 2010 2:36 am

Jilocasin wrote:The Green Sea Slug part plant, part animal.

Ok, that is both seriously weird and seriously awesome. How big is this slug anyway?

Lokathor · Post by **Lokathor** » Sun Feb 21, 2010 2:37 am

http://en.wikipedia.org/wiki/Elysia_chlorotica

"Elysia chlorotica can grow up to 60mm in length but are more commonly found between 20mm to 30mm in length."

CatharzGodfoot · Post by **CatharzGodfoot** » Sun Feb 21, 2010 2:50 am

Carnivorous plants eat animals to get organic nitrogen.

If a creature can survive of photosynthesis, there's very little incentive to do anything, except (if possible) keep away predators and reproduce. If a creature can't survive by photosynthesis, there's more incentive to just eat other creatures.

That said, even humans photosynthesize to some extent. The question is why orcs photosynthesize using the wavelengths that they do. Do you really want to make them tusked dryads?

PhaedrusXY · Post by **PhaedrusXY** » Sun Feb 21, 2010 3:21 am

CatharzGodfoot wrote:That said, even humans photosynthesize to some extent.

No they don't. Photosynthesis has a pretty specific meaning, and humans don't do it. Yeah, there are some reactions that are catalyzed by light in humans (vitamin D, etc), but that doesn't equal photosynthesis by a long shot.

Yeah, non-nitrogen fixing organisms have to get nitrogen from somewhere. Usually that's from eating other organisms (for animals). Plants absorb it from the soil because they don't (usually) do that.

Edit: And that article about the sea slugs is awesome. I'd heard of them taking up the chloroplasts, but the fact that they've incorporated the genes for chlorophyll synthesis is amazing.

koz · Post by **koz** » Sun Feb 21, 2010 3:38 am

Well, orcs as pure photosynthesising lifeforms is probably not tenable, nor does it give me the orcs that people know and (maybe) love. So making them photoheterotrophs seems more likely. This means they partly photosynthesise, and eat meat to supply their nitrogen demands.

What would the advantage of being a photosythesising lifeform be? The obvious one is that you have lower dietary requirements, I guess, but would there be any others I should be aware of?

CatharzGodfoot · Post by **CatharzGodfoot** » Sun Feb 21, 2010 3:53 am

PhaedrusXY wrote:
CatharzGodfoot wrote:That said, even humans photosynthesize to some extent.
No they don't. Photosynthesis has a pretty specific meaning, and humans don't do it. Yeah, there are some reactions that are catalyzed by light in humans (vitamin D, etc), but that doesn't equal photosynthesis by a long shot.

We don't create sugars by using the energy of the sun to split water, but we do use light as an energy source. I apologize for misusing "photosynthesis" to mean 'synthesis of chemicals by means of light'.

Judging__Eagle · Post by **Judging__Eagle** » Sun Feb 21, 2010 4:00 am

K wrote: Considering that humans that can't metabolize copper and ingest it tend to be psychotics, it feels orcish.

Would that explain why they are also a bit stupid?

They probably can't/don't get educations; they can't organize into large scale governments larger than tribes.

Perhaps the placed where Orcs are from have a large concentration of copper; and their ancestors were once humans, how have now gone berzerker?

Red Archon · Post by **Red Archon** » Sun Feb 21, 2010 10:47 am

Sinister, I think you should just call it "magic photosynthesis," which is that missing gajillion times better than what plants do. Since orcs reproduce faster than rabbits (or so it's often written, it is to compensate their very short life spans,) feeding their growing and tumulous tribe becomes harder and harder, because with their ferocity and tendency to kill creatures without the intent to eat them, and to burn down vegetation out of stupidity or carelessness or malice, they probably do tend to be left in areas completely deprived of food. Like a locust swarm that doesn't actually manage to feed itself when they strip areas of consumable materials.

Of course, photosynthesis doesn't provide many types of nutrition, so they'd have to complement it with other stuff. The biologists here probably have a bunch of fun ideas.

Also, if their main source of energy originates from the sun, there's a reversal of the traditional orc...

SRD wrote: Orc Traits:
...
-Darkvision out to 60 feet.
- Light Sensitivity: Orcs are dazzled in bright sunlight or within the radius of a daylight spell.

...which leads to some trouble in them going on dungeon adventures.