GURPS: Ecosystems and Evolution

[Gizensha]

Originally Posted by MagiMaster

Dang. I keep forgetting to write up my thoughts on FP used to hunt. I'm not sure whether or not I'll include it in the final version, but I did have some thoughts:

• Most animals would avoid going below 1/3 FP, since that'd put them in danger from other predators. They'd only burn past that if they were being chased by something already, or otherwise in mortal danger. Let's say most animals will avoid spending more than 1/2 FP at once. Since Basic gives every animal between 10 and 13 HT, they'd have 5 or 6 FP to spend on a hunt.
• It's below the resolution of GURPS, but increasing average FP expenditure should increase consumption. I'm going to make a wild guess that an average creature can expend up to its maximum FP in total per day without losing weight/increasing consumption.
• Pouncing carnivores probably spend this FP one or two at a time for extra effort.
• Chasing carnivores probably spend between 2 and 6 FP sprinting in a few chases per day. (Cheetahs: "Only half of the chases, which last from 20-60 seconds, are successful.")
• Trapping carnivores probably spend the FP building the traps. For creatures as small as spiders, it'd be reasonable to assume that making the webs costs FP, though only slowly. Trapping carnivores probably don't use up as much FP as most other carnivores.
• Hijackers spend FP as per their primary hunting technique, plus one or two for sprinting or extra effort when stealing a kill.
• Scavengers spend FP to sprint in, extra effort some food away, then sprint out (hyenas), or they spend FP hiking to food saving a bit to sprint away from trouble (vultures).
• Grazing/browsing herbivores spend some FP hiking and some for defences. They eat very low quality food, but spend very little effort to collect it (lots and lots of it.)
• Gathering herbivores spend some on extra effort to reach juicy bits of food, and some on defences.
• Decomposers (the moving kind) spend some on hiking or sprinting to get to their next meal, but then save everything else for defences.
• Omnivores do pretty much all of the above depending on the exact animal.
• Filter-feeders, autotrophs, sessile decomposers, parasites and symbiotes don't spend FP except on special defences, or hiking or sprinting while in a mobile form (larva or whatever).
• Of course, any animal might spend some FP on other things. These are just what I think the main expenditures would be.

Did I miss anything? Do you think this info would be useful to a worldbuilder using the rest of the system?

Mainly the FP estimates, I think - I was mainly wanting that for 'If in this ecosystem animals have evolved the ability to cast some spells, how much FP could be justified for a hunt'? - You've given enough to work from for that, I think.

[MagiMaster]

Cool. I think cutting it down to that could make a useful info box.

[GilliganIII]

Has the resulting article of this thread been published or has the info concerning autotrophs moved to another thread? If so could some post/share a link for it here or tell me where I would find it? I am extremely interested because I recently tried something similar only based on the number of species on earth per miles diameter. It would obviously be of different chemical basis for almost any planet based the world generation system from Space, but nonetheless it was still fun to imagine the possibilities. Anyways this post seems to have presented a more realistic way of generating an ecosystem.

[tshiggins]

Originally Posted by GilliganIII

Has the resulting article of this thread been published or has the info concerning autotrophs moved to another thread? If so could some post/share a link for it here or tell me where I would find it? I am extremely interested because I recently tried something similar only based on the number of species on earth per miles diameter. It would obviously be of different chemical basis for almost any planet based the world generation system from Space, but nonetheless it was still fun to imagine the possibilities. Anyways this post seems to have presented a more realistic way of generating an ecosystem.

I'd appreciate if everyone forgave the thread-necromancy, as well. This is fascinating, for me, as a world-builder, and I missed it, the first time around.

Also, a friend of mine is working on a space campaign, and I just sent him the link to this thread. :)

[GilliganIII]

So, I have some questions as to what some equations go where, and how they relate to eachother.

My first is about the population of a species per their biomass. After following the thread back and forth several times, I have come to understand that the equation for the population of a species is either

4*(biomass of species)/(consumption of individual)

or

4*(biomass of species)/[1.25* (mass in lbs)^(-1/4)]

My question then is, am I correct?

My next couple questions have to do with generating the starting biomass for a world and some confusion garnered from Google research.

First I discovered some information concerning the conversion of solar luminosity into biomass via produced wattage;

According to

http://www.astro-ecology.com/Astroec...man_Future.htm

"Assuming a power requirement of 100 Watt/kg biomass"

and

https://www.cfa.harvard.edu/~dfabric...145/units.html

"1 Solar Luminosity = 1 Quadrillion Watts"

so our sun should be generating 140 trillion biomass, but I feel I may have misread something previously in the thread, and so therefore I moved onto this equation;

1,700,000*(Th - Tc)*(area in mile^2)/(height in ft)*(1-sqrt(Tc/Th)

and what I'm wondering is how to convert this for an entire world?
Maybe using the Average Surface Temperature or the blackbody temperature, but more likely the former.
I'm guessing based on your world type and the AST you could determine Th and Tc as extremes for the world, but then I begin to question the height portion.

So I humbly inquire;
Am I overthinking this?
If so is there a simpler way to approach problem that someone would be willing to share?