Microbe Biomes

Biomes are the backdrop for ecosystems in the Microbe Stage. Biomes in the Microbe Stage are mostly preset, unlike in the later stages.

Overview

Biomes define the conditions of the environment in a certain area. Different conditions in different biomes will restrict the habitats of microbial species and lead to the creation of different species of Microbes residing in different parts of the planet.

Environmental Variables

Every biome is defined by a set of physical characteristics. These include light, temperature, pressure, and more. Below is a list of all the environmental variables.

• Variable (unit)
• Depth (m, or meters): How far below sea level the biome is.
• Pressure (atm, or atmospheres): Cells that are adapted to high pressure need to evolve their membranes to migrate into low pressure biomes.
• Temperature (°C, or degrees Celsius): Temperature varies in each area, based on a set value for the biome. Cells can be damaged by temperatures too high or low for them. Thermoplasts and Thermosynthase are more effective at higher temperatures, and these organelles also unlock thermal vision.
• Light (% Intensity): Light will appear in the environment ranging between a set of intensities. It speeds up Chloroplasts, but can also damage cells that haven't evolved protection against solar radiation.
• Currents: How strong the water currents are, affecting the need to evolve more movement organelles or not, and how quickly compounds circulate throughout the environment.
• Gasses: The environmental gasses present in this biome.
• Compounds: Liquid or solid compounds present in this biome.

Though some variables of a biome are relatively constant, some can be subject to change from natural phenomena. For example the ocean surface may start deoxygenated, but years of photosynthesis could lead to an oxygenation event ultimately leading to a build-up of oxygen in the ocean surface.

Regions

A patch is generally part of a greater, collective region of multiple patches. For example, a set of ocean "pelagic" patches may all be part of a large ocean and be grouped into a 'region' to represent that ocean; or they may be part of a shallow sea and be part of a small group with a coastal patch.

Some of the variables of a patch will be inherited from the region it is in. Furthermore, some of the variables will be inherited from the variables of other patches they are attached to. For example, the Sea Floor biome (Benthic Zone) will have a different pressure level based on whether it's the seafloor of a shallow sea, or the seafloor of a massive and deep ocean. If a large scale environmental event occurs that affects the variables of a region, all biomes within that region may be affected because of inheritance. The overall hierarchy of inheritance of factors looks like:

Regions --> "Base" Patches (Epipelagic, Mesopelagic, Bathypelagic, etc.) --> "Associated" Patches (Caves, Sea Floor, Vents, etc.)

List of Environmental Variables

Depth

Depth is measured in meters (m).

Depth itself has no effect on life, and is only descriptive. Instead it predicts or determines other variables such as pressure, temperature, light, etc.

Some biomes are defined by their depth, such as the different oceanic layer biomes (Epipelagic, Mesopelagic, Bathypelagic, etc).

Once we get further into development for the game and start implementing terrestrial and aerial biomes, perhaps it would be better to rename this factor to Altitude or Elevation.

On Terran planets, the base depth range for microbial biomes is from 0 to 6,000 m.

Pressure

Pressure is measured in atmospheres (kPa, with 101 kPa being pressure at sea-level on Earth).

Pressure is directly a result of the depth of a patch, and the fluid makeup of the patch.

On Terran (Earth-like) planets, most fluid bodies will be comprised of fresh or salt water, which have nearly identical densities. As such, pressure in aquatic patches will scale linearly with depth, to be about 1 atm at sea level, and increase by 1 atm for every 10m of depth.

Cells adapted to low pressure will be able to live on ocean surfaces. Cells adapted to high pressure will be mostly constrained to deep ocean patches, and will likely be more isolated.

On Terran planets, the base pressure range for microbial biomes is from 150 to 60,000 kPa.

Light

Light is measured in lux (lx) or percentage (%).

Light is directly a result of the depth of a patch, as well as star intensity, weather patterns, seasons, and the day/night cycle.

Light will not penetrate deeper than 200m into the ocean. As you descent from 0-200m, not all light will penetrate. Depths closer to 200m will have a smaller and smaller spectrum of wavelengths of light that are able to penetrate to that depth, whereas the surface will have nearly the entire spectrum.

The light penetration spectrum of water.

If the game starts in a patch with more than 0% sunlight (possibly due to having Warm little pond or Panspermia as the Life Origin), the player's cell will start with UV tolerance equal to the maximum light level of the patch. Cells evolving in a patch with sunlight present will generally have UV resistance. Aside from this, cells will gradually evolve tolerance to light if they wish to escape competition in the deeper ocean, or if they wish to harness light to perform Photosynthesis (or other light-driven metabolic processes).

On Terran planets, the base sunlight level range for microbial biomes is from 0 to 100 %.

Temperature

Temperature is measured in degrees Celsius (°C).

For Terran Planets, temperature decreases by depth according to the following pattern.

The change in water temperature with increasing depth, with differences in latitudes and seasons shown.

High latitude biomes (far north and far south) are equally cold from the surface to the ocean floor. Meanwhile, tropical patches experience the greatest fluctuation from surface to sea floor, with the surface being very warm and it then rapidly dropping in temperature as the water gets deeper. Seasonal temperature variations are minimal as even winters in the tropics will likely be warm and sunny. Temperate biomes are a mid-ground, with a reasonable decline in temperature as depth increases, and with seasonal variation of surface temperatures year round.

Adaptation to higher temperatures will allow cells to live in ocean surfaces and shallow waters in warmer parts of the planet, with the most extreme adaptations allowing cells to live near hydrothermal vents or in geothermal pools. Colder temperature adaptations will allow cells to live in the deep ocean or in the oceans of the far north or south, and extreme adaptations allow living near ice shelfs.

On Terran planets, the base temperature range for microbial biomes is from -1 to 98 °C.

Currents

The currents of a patch range between low, medium, and high. This simply determines the strength of currents generated in that biome.

Stronger currents in a patch make it harder for mobile organisms to evolve. It greatly incentivizes sessile living, since currents will be hard to swim against and will bring compounds to you anyway. Cells that evolve to attach to each other or to foreign surfaces (like floating chunks) will be greatly incentivized, as they will be able to anchor themselves against the strong currents.

Weak currents in a patch make it easier for mobile organisms to evolve, as there will be little hindrance of their mobility and so they will be able to stay mostly in control of their own movement. Such patches will likely experience much more active predator species.

Salinity

This is not currently featured in the game. It may be added later on.

The concentration of salt in the water. Salinity distinguishes aquatic patches between saltwater and freshwater.

Cells that are adapted to high salinity need to evolve their membranes to migrate into low salinity biomes. Salinity in a patch is measured in parts per million (ppm).

Atmospheric Gasses

A planet shares gasses between the atmosphere and the oceans. Gasses from the atmosphere dissolve into the ocean, and gasses in the ocean bubble up into the atmosphere. The amount of these gasses found in any patch vary by its biomes, and can be affected by various events. Gasses will flow between patches based on natural processes, and natural events (including microbial bioprocesses) can create a concentration or deficit of a gas in one/several patches, but this will equilibrate over time.

Compounds

As well as environmental gasses, usable compounds are found in every patch. These are required for bioprocesses such as osmoregulation, growth and reproduction, and respiration. They are found either as compound clouds or as floating chunks.

Environmental Tolerance

The physical and chemical boundaries of life will make each species only able to tolerate a certain range of each Environmental Variable. The Tolerances tab in the editor has a bar (or set of bars) for each variable, with an arrow to indicate the value for that variable in the current patch, with current tolerance values displayed above. For Temperature and Pressure, the maximum and minimum that your species can tolerate are listed, and for Oxygen and UV, the maximum value your species can tolerate is shown. If any value is outside of your tolerance range, or above your maximum, the value is outside of tolerance for that variable.

Every member of a species that's in a patch with variables outside of its tolerances will receive penalties to its cellular functions. This will be in the form of increased base energy requirements (osmoregulation), reduction to maximum health, and/or reduction to the speed of its compound processing organelles (organelles that turn one compound into another, including ATP). The penalties, per variable, are:

• Temperature: +2.5% osmoregulation cost, -2.5% health and -2.5% bioprocess speed for every 1°C out of range, to a maximum of 20%.
• Pressure: +1.5% osmoregulation cost, -1.5% health and -1.5% bioprocess speed for every 50kPa out of range, to a maximum of +10% osmoregulation cost, -50% health and -20% bioprocess speed.
• UV: +1% osmoregulation cost and -1% health for every 1% below current UV level, to a maximum of 50%.
• Oxygen: +1% osmoregulation cost and -1% health for every 1% below current oxygen level.
• Salinity (if this factor is added): -10% efficiency for every 1000 ppm out of range.

These penalties stack, so if you are 20 atm out of your depth tolerance, and 5% out of your light tolerance, you will receive an overall 20% penalty to your cell's efficiency. This will mean species are encouraged to live within the biomes they're adapted to, or evolve to adapt to new biomes if they want to compete there. It will also drive species to diverge if living in separate biomes.

Bonuses

For the following variables, getting within the tolerance range while keeping the range itself very small will provide a bonus to your species. These stack with any penalties from other variables.

• Temperature: +10% bioprocess speed for being with tolerance range at a maximum flexibility of 1°C.
• Pressure: +20% health for being with tolerance range at a maximum flexibility of 300kPa.

List of Microbiomes

The current list of biomes can be found on the Microbe Appendices page here.

For the direct link to the spreadsheet look here.

Previous Concepts

These concepts are no longer widely supported for inclusion in the base game.

Acidity

Acidity is typically always neutral, and is only found in extremely low or high levels in brine seeps, near hydrothermal vents, or in geothermal pools. Planetary climate change can also result in oceans increasing or decreasing in acidity. For example, an increase in atmospheric carbon dioxide will lead to acid rain that can lead to ocean acidification.

Acidity in a patch is measured on the pH scale. Cells that are adapted to neutral pH need to evolve to tolerate highly acidic or basic environments.