Multicellular Stage: The Beginning

[crodnu]

So, since there’s not a lot of information about the early multicellular stage and how it begins (the most relevant thing i could find being this thread from 3 years ago http://thrivegame.canadaboard.net/t1460-multicellular-stage-design?highlight=multicellular) i decided to make this thread so we can have some general consensus on that.
Warning: i’m not a biologist by any stretch of the imagination and i get info from wikipedia xD

So mi idea is as follows:
When you are done reproducing all your organelles in the microbe stage and are ready to enter the microbe editor you get another button to split but stay attatched, and when you click it you start multicellular stage.
You then get to chose where your new cell will be attatched to (with an in-stage editor perhaps?)
Not a lot happens to begin with (other than changing to the multicellular stage theme if we already have it), and you keep playing as your 2 celled organism.

However this unlocks a bunch of new functionality:
A) You can disable/enable cell reproduction on each cell, and when a cell splits you can only put the new cell besides it (only cells on the outside can reproduce? or in the inside too and it moves all the other cells around? or soft-body magic?). You can make a bunch of them at the time to avoid tedium.
B) You can kill your own cells by clicking on a button and selecting the cells, and this gives you back their compounds (maybe? it could be exploitable). Useful for trichocyst blasts.
C) You can make cells (or groups of cells?) on the outside of the colony detach from it, which would make them act like spores, and after enough of them split (depending on the organism size?) you can reproduce and enter the multicellular editor. You can then continue playing as one of the spores. If the spores are single cells, then you would be back in the microbe stage.

On the multicellular editor you can create new cell types or edit existing ones. Your original cell type (which should also be a part of all the spores) can create all cell types, while the other types can only create more of themselves (or something like that idk, maybe cells can only make similar cell types? and it becomes some sort of a tree?).
It’s also note-worthy that peripheral organelles like pili and flagella are useless in the inside of the cell.

That’s all i can think of so far. Any ideas/suggestions?

[NickTheNick]

Good find, that thread has a lot of the information on the subject.

Basically, I think that Early Multicellular should play out very similar to the Microbe Stage. In fact, in many ways it will be just like you are in the microbe stage, but instead of playing as one microbe you are playing as a bunch that are clumped together.

Also you have some good ideas with being able to toggle the reproduction of your cells, select ones to kill off, and select ones to break off. After discussing the Editor those are some good ideas for talking about the gameplay.

Editor

The main thing that we have concept planned out for is the editor. Basically the Multicellular Stage features the same editor as the Microbe Stage but with some expanded options (let’s just call it the Multicellular Editor for now. In this editor, you edit everything the same way as you do in the Microbe Editor. The difference is that you can now create Types of cells for your colony (like Tissue). All of the cells of your colony start out as the same type. The importance of a type is that any change made to one cell of a type is automatically identically applied to all cells of that type. Add a mitochondrion to the top right corner of one cell of the default type and now all of your cells of that type will have an extra mitochondrion. The duplicates of the mitochondrion are completely free, so the MP cost is still just 25. This represents how these cells are all coded for by the same DNA, so even if there are more of them a change to the shared DNA is reflected in all of them.

However, things start to get interesting when the player makes new types. The player can create a new type and designate however many cells that he wishes to belong to this new type. Now the player can apply changes to one type while leaving the other alone, or vice versa. Using this system of types, you can create a whole set of specialized types of cell for your colony. You start with all of them being default type, then after a few generations maybe half (the ones on the outside) are protective and half (inside) are digestive, then a few generations later and some are motility cells and some are communicative cells, etc.

Also you can always add or remove cells of any type to your colony, and they will always be identical to other cells of that type.

Here’s a summary of it:

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MULTICELLULAR EDITOR

Types of actions
Add/remove cells of a type – 25 MP
Edit the design of cells of a type – Standard Microbe Editor costs
Add/remove types – Free
Designate cells to a type – Free

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I don’t want to throw down too many things to talk about for now, so what do you guys think about the editor concept?

[hhyyrylainen]

I think the editor concept sounds good. But the reproduction needs to be designed, too.

What I’ve been thinking is that in multicellular you initially reproduce by splitting off a single cell of your clump of cells (perhaps a type that’s optimized for being a single cell for a while) and then you get to enter the editor and design which cells your organism will have when fully grown. Then you go around and collect compounds in order to split enough times to finish your organism’s cell layout plan. Then you can reproduce again.

Reproduction would work like this until you develop sexual reproduction when you would have to find another clump of your species to reproduce. I think this is more realistic than the new cell colony starting off with all the cells you have designed. And provides similar gameplay to the cell stage where you collect enough compounds to split.

[crodnu]

I also think having your colony be big after reproduction could be a little unrealistic, that’s why in my idea there are 2 different editor. One is for creating cell types (which would later become tissues, maybe) and the other one would be before reproduction, and it would allow you to place cells in your colony after the cells split. This editor would exist inside of the stage (kinda like the tribal and city editor in spore), and as far as i understand is very similar to what we have planned for plant gameplay.

You need to release a large enough amount of cells/group of cells in ordered to be able to enter the cell type editor, and after that you would play as the spore itself, in the microbe stage if it had only one cell.

[hhyyrylainen]

Do we need an editor for positioning cells inside the stage, or could we do with a predefined cell layout?

Like this: you are now a multicellular thing -> in the editor you can place multiple cells -> you start with the stage with a single cell -> whenever you have enough compounds for your cell to split you split and get one more cell filled in the layout you made in the editor -> once you split enough times to complete your clump of cells you can reproduce and enter the editor again to edit the cell layout and respawn as a single cell to start the cycle over.

[crodnu]

That would require the player to define the entire layout the first time they enter the editor, and it could be complicated to decide the priorities of the cells that get created (it would get especially complicated if cells in the middle of the clump can split). No idea at what point the creatures should start having a predefined look, or what mechanics should dictate that tho…

[NickTheNick]

Hm, this is an interesting point to discuss.

I think the first thing to consider is the transition from unicellular reproduction to multicellular reproduction and making it as seamless as possible. From what I understand, I think the current and default reproduction method is binary fission, where the cells just double in size and then split. So what would be the natural continuation of binary fission in a multicellular colony?

Budding
I feel like the natural continuation of binary fission would be the colony doubling all of its cells in size and splitting them one by one. Either it does one or groups of cells at a time, or it does them all at once. This is basically equivalent to budding. The problem I can see with this (particularly if it’s the default reproduction system) is that it requires a lot of micromanagement to ensure all of your cells are healthy for reproduction to progress.

Spores
I like hhyyrylainen’s idea of releasing a spore to grow a new colony. It’s sort of like you never left the Microbe Stage, because every time your colony reproduces you go back to being a single cell. Plus, it’s a lot easier to manage growing a single cell to a colony, instead of growing a colony to double its size and then splitting it.

Which approach do you guys think fits better as the default reproduction system for multicellular?

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To put the spores idea of hhyrrylainen into context, this is what it would look like in gameplay (from what I understand it, so please correct me if I’m wrong).

• The player is a unicellular microbe.
• The player enters the editor and evolves binding agents and signal agents. When they leave the editor, their microbe splits but the two cells stay attached.* This marks the official transition to the Multicellular Stage.
• The player, now a 2-cell colony, hunts and survives as per usual. When the original cell of the colony reaches double its size, the player reproduces and enters the editor.
• In the editor the player now has access to the multicellular editor. He adds 4 more copies of the default cell type to his colony (bringing it to a total of 6 cells).
• When the player leaves the editor, it shows an animation of a third cell splitting from one of the cells of the 2-cell colony. This third cell is the player, and does not stay attached. Instead it swims off.
• The player in control of this new cell, grows a new colony. As the player hunts and survives, he will naturally split (not entering the editor), creating new copies that stick in place just as was designed in the multicellular editor. This continues until he forms a colony of 6 attached cells. Now the colony is formed, and the next reproduction will take him to the editor, where he can evolve his colony.
• When the player’s original cell doubles in size for the 7th time, now he enters the editor. He makes his changes and when he exits he takes over a new cell that detaches from the colony and starts a new colony.

*If only signal agents were evolved, the other cell would stay around and mimick the player’s actions but not be attached. If only binding agents were evolved, the other cell could detach at any point to do its own thing and would have its own AI.

Did I understand you correctly about your idea?

[hhyyrylainen]

@NickTheNick

Did I understand you correctly about your idea?

Yep, that was pretty much what I tried to say.

[NickTheNick]

Nice! So in that case, which reproduction method do you guys think better suits as the default of the multicellular stage (budding or spores)?

And also, how should new reproduction methods be unlocked (like sexual reproduction)?

[hhyyrylainen]

I think the spores approach would be much easier to implement, so we should try to make that first and expand later.

[crodnu]

I like the spores better too, but i think more than 1 spore should be released maybe.
Also we have to take into account the possibility that the original cell (or any cell really) gets destroyed.
Also i’m still not sure about the layout. Imagine that the colony is a circle of photosynthetizing cells with pili cells on the outside. The best way to grow would be to make a small circle and grow it overtime but if we use a layout it wouldn’t complete the outer defensive layer until the end which would be really disadvantageous.

[hhyyrylainen]

It’s not optimal to create the layout before entering the stage, but it will be much harder to make new editing controls that work inside the cell stage and allow you to edit the position of your cells (in realtime?).

[crodnu]

i meant in inside the stage but paused (like the city and tribal editors in spore), it could be in another editor like the cell type editor but i just thougth that would be kind of annoying to do every couple of minutes.
and setting the priorities in the layout (which cell to make first) could potentially be even harder, with the complexity being analog to the process system (for example, if a colony has a chemosynthetizer cell and a photosynthetizer cell in the layout, which one to make first?)

[NickTheNick]

Hm, maybe we could have a priority list in the editor. You can then categorize the different cell types of your colony into a list, so that when you are multiplying in the environment, the game knows which cells to make first.

Speaking of which, I realized we need some new terminology for these concepts. I would suggest “Proliferation” as the process of having your cell split to form new cells to form/fill-up the colony. “Reproduction”, on the other hand, is when a cell splits to form a spore, which doesn’t attach to the colony and instead swims out to start a new colony (but first initiates the Editor).

Also, crodnu raises a good point. What if the original cell of your colony dies? Should proliferation and reproduction be tied to the original cell? Or should any cell be able to profilerate/reproduce?

[crodnu]

My idea (as i pointed out in my original post) was to make the original cell type the one able to proliferate into other cell types (with other cell types being only able to form cells of the same type), and of course being needed in the spore (which could maybe have more than 1 cell?). The original cell type would then by some sort of embryonic tissue, like the meristems in the plants or the stem cells in the animals.

[NickTheNick]

Ah fantastic idea! That actually got me thinking, what if when the player creates new cell types in the multicellular editor, they form a tree? The player starts with the original cell type at the top of the tree. The first new cell types have to branch off from that original node. However, the next time you come to make cell types, you can branch them off from any of the secondary nodes or the original node. When proliferating in the environment, cells can only proliferate into cells of their node or lower.

EDIT: Something like this:
https://www.researchgate.net/profile/Katherine_King3/publication/51635992/figure/fig3/AS:279058823827473@1443544216249/Figure-1-The-haematopoietic-treeLong-term-haematopoietic-stem-cells-HSCs-have-the.png

Or would that be too much added complexity for not enough gain?

[NickTheNick]

I’ve done some more reading and thinking on the subject and I think I have come up with a concept for reproduction that fits in the evolution of sexual reproduction and is continuous with reproduction in the Microbe Stage.This concept is a fusion of spores and budding. It helps fill in the gaps of what earlier concept was missing.

So, time for some new terminology:

A cell can either be a germ cell or a somatic cell.

1. Germ Cell - Any cell that can split itself to produce “sex cells” (called gametes), such as an egg or sperm cell. One of each type of sex cell must come together to form a new colony.
2. Somatic Cell - Any cell that is not a germ cell. They cannot split to form “sex cells” (gametes).

A cell can also either be a stem cell or non-stem cell.:

3. Stem Cell - Any cell that can split to form different cell types.
4. Non-Stem Cell - Any cell that can only split to form more of itself.

Germ vs Somatic Cells

So a cell can be either a germ cell, where they can form sex cells to form new colonies, or they can be somatic cells where they are just standard.

By default, all colonies will reproduce asexually, so no cells will be germ cells. A colony can evolve its original cell type to become germ cells. Question for discussion: Should we allow any cell type to be able to be evolved into a germ cell type, or only the original cell type? I think that for the sake of simplicity we should only allow the original type to be evolved into germ cells.

Stem vs Non-Stem Cells

A cell can either be a stem cell, where they can split to form other cell types as well, or they can be non-stem (I remember there being a word for this) where they can only split to form more of their own type.

Based off of our discussions so far, it seems like the original cell type should be stem cells and all newly created cell types will be non-stem. In other words, cells of the original type can split to form any other type, but cells of the other types can only form more of themselves.

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With these definitions in mind, let’s now look at reproduction.

The original cell type is somatic and stem (can’t make gametes, can form any cell type). When the player creates new cell types, they will always be non-stem. They will also be somatic.

The player can evolve their original cell type to become germ, but not the other cell types (unless we decide otherwise in the question posed above).

Sample Gameplay

When the player first exits the microbe editor with signal agents AND binding agents, they will see their cell split. However, for the first time, the two cells will stay stuck together and will be simultaneously controlled by the player. This marks the entry to the multicellular stage. These two cells together are the original colony (each hex represents a cell).

These two cells will continue to grow and replicate their organelles and progress towards reproduction just as in the microbe stage. The only difference is, now when the cells complete a cycle of reproduction and make a new copy of themselves, the player doesn’t enter the editor. Instead, they will need ALL of the cells of their colony to duplicate themselves before they can split the colony and enter the editor. For the original colony, this means growing until it goes from 2 to 4 cells.

Once the entire colony has doubled, the colony stops growing and cannot continue to grow (Or, new cells will continue to be produced but they will break off immediately after forming). The reproduce button becomes available for the player and pressing it will take them to the Multicellular Editor (as detailed above). Let’s say that in the editor the player adds two more cells of the original type to the colony.

After exiting the editor, the player watches their colony split. In this example the four cells split into two colonies of two cells. They take over one of these new colonies. The player then grows their colony of 2 cells until it reaches 4 cells, which is the new standard size that was designed in the editor. Then it continues to grow and replicate until it has 8 cells, which is double its normal size and is the first step of reproducing.

So far, this is all based off of the budding approach and not what @hhyyrylainen suggested. The reason I think that budding is better in this part is because it is very similar to the form of reproduction before (grow bigger, then split) and is very simple. However keep reading.

Eventually, the player will develop specialized cells. When a colony starts to grow a bud for a new colony, it only grows the stem cells of that colony. Then the bud will break off and the stem cells will keep reproducing to fill in the rest of that colony. For example, say I have a colony of 5 stem cells (the original cell type) and 5 protective cells (a specialized cell type). When I start forming a bud, the bud grows 5 stem cells, then it breaks off. I take over those 5 stem cells, and they continue to grow and split to produce the remaining 5 protective cells. Now I have a full new colony of 10 cells.

So in this way the cell doesn’t bud off an entire new colony, but also doesn’t just send out an individual cell as a spore. I feel like the problem of unicellular spores, as @hhyyrylainen suggested, is that it means your stem cells have to be very well designed for surviving on their own. It also means quite slow gameplay when you first break off as a spore and have to grow an entire colony on your own.

I would call this form of reproduction partial budding, and it would be the default form of reproduction for every colony. Spores and Full Budding would be possible alternatives a colony could evolve. Spores would be @hhyyrylainen’s idea, and Full Budding would mean growing the entire new colony as a bud before it breaking off (instead of just the stem cells).

Sexual Reproduction

Eventually the player can evolve sexual reproduction. In the editor, they would edit their original cell type and make it into a germ cell. During gameplay it would look like this: The colony is swimming around. When it is ready to reproduce, the stem cells produce a gamete and release it into the environment. If it interacts with a gamete of the other type (male with female or vice versa), then they fertilize and fuse and form the first stem cell of a new colony, which the player now takes over. This stem cell grows until it has become a whole new colony.

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What do you guys think of this concept?

[crodnu]

I think partial budding has some issues:

1. How would the stem cells grow? If it’s not done carefully the player could end up growing a crippling tumor of stem cells.

2. Having just one stem cell is the optimum, since you only require to split it once, which reduces the amount of most likely unwanted stem cells both in your old organism and your new one.

3. How do you handle the stem cell being in the middle of a colony? (a likely scenario because of 1).

4. Sexual reproduction would still turn into something similar to our original concept of spore mechanics (which, btw, i mentioned first )

[NickTheNick]

Very good questions.

1. The stem cells grow only until they reach the number designated by the player in the Multicellular Editor. If growing the stem cells of a bud, the bud will grow on the exterior of the colony. The bud will force the colony to survive with more cells than usual but that would be the tradeoff of reproducing. Also I’m not too familiar with how easy/hard it’d be to code and animate this. I’m just imagine that if an interior cell would split they would push out the surrounding cells. Something like shown in this video (the cells reproducing on the inside):

Bacteria Growth

2. I’m a little confused, what do you mean by unwanted stem cells? Theoretically your colony will never produce excess cells, only the ones designed for your colony in the editor.

3. Stem cells growing on the inside would have to migrate to the edge and then break off. Also now I see what you mean by talking about a crippling tumour, because maybe you have a surrounding layer of protective cells and what if the bud’s growth breaks that barrier. I would say either buds can grow inside as well, or that is the tradeoff of budding and the player would thus have incentive to evolve spores or sexual reproduction. It would give a neat trick to keep budding for smaller organisms (like in LAWK).

4. Ah my bad, credits to you for that then . That’s a good point that spores and sexual reproduction are pretty similar in our current concept, so I think we should make it so that colonies that reproduce sexually receive a 25% discount to all MP costs in the editor. This is to simulate the fact that sexual reproduction offers a species the possibility to have a lot more genetic diversity and each member can have a different phenotype, as well as each sex. In game spores and sexual repro should be distinguished by spores being relatively easy to grow and send out, which can then start growing its own colony immediately, whereas gametes take a while longer to grow and send out, and also need to find and match with another gamete before they can fertilize and start growing. Sexual repro’s tradeoff would be quicker evolution for slower reproduction.

[NickTheNick]

What do you guys think of partial budding? Does it make sense/work as a default mode of reproduction before spores or another system is evolved, or is it better that we stick with Spores as the default mode.