So the idea has been raised a few times of having the Microbe Stage start earlier, as in with the first cell, not just the first eukaryotic cell. Here we can discuss whether it’s a viable idea and how it would work. I think it’s a good idea, but it does bring up many questions about how we would transition from prokaryotic to eukaryotic gameplay. One option is to simplify the prokaryotic phase a little bit so the it’s just a few generatons of swimming and hunting until you evolve a nucleus+ER+Golgi and become a eukaryote, and then unlock the fully detailed gameplay from that point on. Another option is not to simplify it, in which case I have an idea for it’s design below.
I’ve been thinking about it on and off and these are my ideas on how it could work. Obviously this is all a WIP, but points I am particularly unsure about will have a “(???)” at the end.
- The game starts with a brief cutscene where the player has no agency. It shows a small droplet of membrane floating through the water (a micelle/protocell). It then bumps into and absorbs a small strand of DNA, which floats into the center of the membrane and remains intact. This is the formation of the first cell. The player takes over this original species.
- As explained in this thread, the original ocean will start with plentiful free-floating clouds of organic molecules (like glucose, amino acids, nucleic acids, etc).
In fact, it’s more accurate to have the free floating organic molecules be around during the prokaryotic phase, since by the time eukaryotes evolve most of the free floating clouds would be gone since oxygenation would likely have occured. If you don’t know what I’m talking about read the thread I just linked above.
- The compounds that will be found free-floating are:
- Glucose, which the original species eats to make ATP.
- Amino acids, fatty acids, and nucleic acids. The cells use these to grow, reproduce, and heal themselves.
- Iron, hydrogen sulfide, manganese, and hydrogen cyanide. Cells can evolve chemosynthesis to metabolize these compounds. More on this in the adaptations section.
- The other cells in the beginning will all be members of the original species. However, they will quickly diversify into their own species in the first few generations.
- There will be free floating pieces of DNA called plasmids. The player requires phagocytosis to absorb these. Consuming them gives a small chance to receive a discount to editor costs the next time they reproduce (this represents the acquiring of foreign DNA increasing your gene pool), OR it could unlock an adaptation in the editor. The appearance of plasmids will diminish over the generations, both from other species eating them up and from an Oxygenation period if one happens.
- Should NPCs allowed to become eukaryotes before the player?
- The starting cell will be extremely simple, basically just a membrane and the DNA strand you started with.
- For movement, it can just drift slowly in different directions.
- The starting cell can absorb small molecules through it’s membrane (Pinocytosis). It cannot, however, absorb large molecules or other cells.
- The starting cell can only perform glycolysis, which means it can convert glucose into ATP to use as energy.
- The starting cell can store compounds in its cytoplasm.
- Simple chemoreception. The cell starts with the ability to see a small radius around itself (representing the ability to weakly detect concentration gradients of chemicals).
- Cells cannot initially recognize each other, and thus members of your own species will still try to eat you.
- It’s assumed that the original species starts with a simple cytoskeleton. This doesn’t affect gameplay.
The following is the list of evolutions a prokaryote can evolve to adapt their cell. A lot of these are just taken from the list of adaptations for a eukaryote, so we should probably go through and cut out ones prokaryotes shouldn’t be able to acquire.
- Phagocytosis: The cell can absorb large molecules and other cells.
Cell Wall: Reduces speed and maneuverability but makes you much more resistant to physical damage and toxins and extreme temperatures and engulfment and extreme acidity (or we could make it so that the cell wall has to be evolved to be particularly good at one of these forms of protection).
- Fused Cell Wall: When the cell reproduces, the cell wall does not split and instead encloses both new cells. This allows for colonies to form inside a shared cell wall. (???)
- Membrane Coating/Capsule: Can be adapted to protect against toxins or engulfment or acidic environments. Instead of slowing down the cell like the cell wall it simply uses up a lot of glucose and amino acids and fatty acids to repair when damaged and to grow when reproducing.
- Internal/Osmotic Pressure: Change the internal pressure of your cell to allow it to migrate to other parts of the ocean with different water pressure levels.
- Invaginations/Folded Membrane: Increases the surface area on your cell.
- Vacuole: Allows the cell to store things more efficiently by inverting part of its membrane to form internal sacs.
- Contractile Vacuole: Allows your cell to change its internal pressure by sucking in or ejecting fluids, allowing it to tolerate a range of pressures.
- Endomembrane System (Endoplasmic Reticulum + Golgi Apparatus): Should this require invaginated membranes or vacuoles? Allows the cell to do something, but I’m not sure what, since it appears prokaryotes can already create proteins aka agents. (???)
- Nucleus: Encloses the DNA inside an inner membrane. Not sure what evolving this would do. Maybe this has a small chance of unlocking when you consume other cells? Should the Nucleus be included as part of the same adaptation as the Endomembrane System? (???)
Cilia: Come in three forms.
- Motility Cilia: Cilia adapted to move the cell. Grant the player small boost in speed and good maneuverability for medium ATP cost.
- Sensory Cilia: Cilia adapted for sensation.
- Directed Cilia: Cilia that beat to push surrounding molecules or cells into a “mouth” area on the membrane. (???)
Flagellum: Grant the player high boost in speed and small maneuverability for high ATP cost.
- Pilus: Replaces an existing flagellum. Allows the cell to ram into and puncture other cells. Stronger at physical damage than a fimbria.
- Fimbria: Replaces an existing flagellum. Allows the cell to ram into and puncture other cells and steal their DNA or inject them with toxins or steal their compounds.
- Cilia: Come in three forms.
- Anti-freeze Protein: Allows this cell to survive sub-freezing temperatures (down to around -25 degrees Celsius).
- Heat Resistant Protein: Allows this cell to survive temperatures above 40 degrees celsius. (Each upgrade to this protein boosts the cap with diminishing returns. The boosts plateau at around 80-100 degrees).
- Lysosomes: Allows the cell to much more effectively digest large molecules and other cells that it consumes.
- Digestive Enzymes: Allows the cell to eject proteins that will digest hostile cell walls or cells or large molecules, which the cell can then go and slurp up.
- Peroxisomes: Allows the cell to detoxify hydrogen peroxide and alcohols and other things that are toxic to it (like oxygen if the cell is anoxic). (???)
Photoreceptor Protein: Allows the cell to detect light. Step 1: Presence/Absence, Step 2: Gradients/Direction.
- Lightspot/Eyespot: Requires photoreceptor protein. Allows the cell to more easily see light and have an expanded visibility radius.
- Chemoreceptor Protein: Allows the cell to detect chemicals. Step 1: Presence/Absence, Step 2: Gradients/Direction.
- Thermooreceptor Protein: Allows the cell to detect heat. Step 1: Presence/Absence, Step 2: Gradients/Direction.
- Electroreceptor Protein? Mechanoreceptor Protein?
- Binding/Adhesion Protein: Allows the cell to stick to other cells of its species.
- Signal Protein/Agent: Allows the cell to communicate and coordinate with other cells. Comes in different forms. Allows cells of the same species to recognize and not attack each other. Later iterations allows them to cooperate and then even coordinate (Quorum Sensing).
- Bioluminescent Protein: Creates bioluminescence.
- Pigment Protein: Allow your cell to withstand UV radiation and gives it a particular colour.
- Acid/Base Resistant Protein: Allow your cell to withstand more extreme acidity/basicity.
- Energy Synthesis Proteins
- Photosynthetic Protein (Chlorophyll): Allow your cell to perform photosynthesis.
- Respiration Protein: Allow your cell to aerobically respire (breathe oxygen).
- Fermentation Protein: Not sure what the chemical process would look like. It looks like there are a few different forms of fermentation. Is this just glycolysis?
Chemosynthetic Protein: The problem is there is no one set way to perform chemosynthesis, it’s just a category for many ways to obtain energy from chemicals.
- Nitrogen-fixing Protein (Nitrogenase): Allow your cell to perform chemosynthesis by turning nitrogen into ammonia.
- I’m not going to go through all of them right now. This page goes through many of the possible chemosynthesis, photosynthesis, and thermosynthesis processes that are possible. The point here simply is that eukaryotes must evolve an enclosed organelle to perform these processes inside of, but prokaryotes can just evolve a protein and do it in their cytoplasm. The question is what happens when a photosynthetic prokaryote becomes a eukaryote. Does it automatically acquire a chloroplast? I feel like that would be the simplest solution.
- Cryobiosis/Endospores: Allows your cell to freeze all processes and enter a dormant state until conditions are favourable again.
- Horizontal Gene Transfer I: The cell can try to acquire the DNA of cells that it eats (Transformation). This has the same effects as absorbing a plasmid.
- Horizontal Gene Transfer II: Requires HGT I. The cell can stick to other cells and try to acquire some of their DNA (Transduction/Conjugation).
- What can the prokaryote not do because of the lack of nucleus and golgi+ER? How do we incentivize the player to evolve these? (I thought they wouldn’t be able to produce proteins/agents but turns out they have ribosomes as well)
- Yes, this is a belgium-load of adaptations, but I think if we can present them properly to the player it will make the game more fun not more confusing. It will make it possible to have so many different types of life in different environments and each replay of the game will feel different.
- We do need to rescale the hex grid to allow smaller organisms, since prokaryotes are about 100x smaller than eukaryotes.
- Adaptations that we want to restrict to prevent cells from acquiring right away can be locked at first and require acquisition of plasmids or DNA stealing from other cells to unlock.