When I run a simulation with only this animal on Tundra:
Biome: Tundra
Venomous: No
Weapon: 0
Armour: 1
Speed: 0
Eats: Seeds
Cold (Allows survival in the Tundra): Yes
It goes down to 2-3 population for a while, and then dies after 25 generations.
However, I calculate the size is 1.85 (0.1 base + 0.75 armour + 1 eats seed size), and it should only need 20% of that in food per turn, which is <0.4. Tundra has 1 seeds per turn, which should give 5 food. Does anyone have an explanation why it doesn’t stabilize around a population of 5⁄0.4≈12?
I’m not sure if I just misunderstood the mechanics, or if maybe I messed up something when testing the code, but would be grateful if anyone could clarify what should happen in this situation.
There is a random element in reproduction. If your animal would have an average of let’s say 1.1 descendants, what actually happens is that it gets 11 separate 1-in-10 chances to reproduce, and could in theory produce any number of descendants from 0 to 11 (though with an average of 1.1).
On average, with large numbers of animals, this averages out the same way. However, when your population is very small, there’s always a chance that it’ll randomly die. I imagine this is what’s going on with your population, though not certain.
Thank you aphyer! You’re absolutely right, the size is 3.85, so it needs like 0.8 energy per turn.
5⁄0.8≈6, with this number it’s more likely for the animal to die out by random chance.
I redid the experiment on the Benthic biome, and removed the cold resistance, set Seeds in the biome to 1, and the species survives with around 6-21 in population, which is around the population of 12 we would expect.
A question about mechanics:
When I run a simulation with only this animal on Tundra:
Biome: Tundra
Venomous: No
Weapon: 0
Armour: 1
Speed: 0
Eats: Seeds
Cold (Allows survival in the Tundra): Yes
It goes down to 2-3 population for a while, and then dies after 25 generations.
However, I calculate the size is 1.85 (0.1 base + 0.75 armour + 1 eats seed size), and it should only need 20% of that in food per turn, which is <0.4. Tundra has 1 seeds per turn, which should give 5 food. Does anyone have an explanation why it doesn’t stabilize around a population of 5⁄0.4≈12?
I’m not sure if I just misunderstood the mechanics, or if maybe I messed up something when testing the code, but would be grateful if anyone could clarify what should happen in this situation.
There is a random element in reproduction. If your animal would have an average of let’s say 1.1 descendants, what actually happens is that it gets 11 separate 1-in-10 chances to reproduce, and could in theory produce any number of descendants from 0 to 11 (though with an average of 1.1).
On average, with large numbers of animals, this averages out the same way. However, when your population is very small, there’s always a chance that it’ll randomly die. I imagine this is what’s going on with your population, though not certain.
(Also, your animal is larger than you think: Cold Resistance has a size cost of 2, so your animal’s size is actually 3.85)
Thank you aphyer! You’re absolutely right, the size is 3.85, so it needs like 0.8 energy per turn.
5⁄0.8≈6, with this number it’s more likely for the animal to die out by random chance.
I redid the experiment on the Benthic biome, and removed the cold resistance, set Seeds in the biome to 1, and the species survives with around 6-21 in population, which is around the population of 12 we would expect.