We start our journey at the smallest scale of us – our cellular biology. We start here as it help set some of the foundational interactions that at scale make you you, me me and them them.

The very basic cell

Life is incredible. That incredibility can be looked at different ways. One way is the philosophical one of beauty. Another equally beautiful view is of chemistry and biology where the interactions of atoms and molecules drive the formation of complex things resulting in us, our brains, and our consciousness to a point where I can write something, you can read it and machines can translate into other languages. It can also create things of horror and pain that are hard to imagine. In order to understand this complexity let’s break things down into simple models.

The cell is the single unit of all sustainable life (viruses are cheeky as they hijack the cell to make copies of themselves before infecting others). All cells have three main parts that we are going to start with:

1. Instructions: a set of instructions to make more copies (reproduction)
2. Engine: apparatus that enables the cell to grow by taking in nutrients
3. Boundary: a barrier between the inside and the outside

That’s it. Clearly it’s more complicated but this will do for now. The next thing we need to add are the components needed for growth.

1. Materials or building blocks
2. Energy
3. Oxygen

Again to keep things simple I’ll ignore organisms that don’t use oxygen to live and all those awesome things are live in awesome conditions like super hot, super acidic and other super conditions. These are extreme and aren’t relevant to explaining how we work. The conditions I’m talking about are aqueous (based in water) which is moving a little, temperature is around 15 degrees Celcius. These conditions are easy to understand as they are the conditions we see everyday. Now, acidity is little complicated but again let’s say it’s neutral which means there are no additional hydrogen ions floating about (I’ll explain why acidicity is important later on; for now just add it to the list of things that can change.

OK. Now, a key thing to realise is that this is pure chemistry – there is no one making decisions just chemicals bouncing around into each other joining together, breaking apart, wobbling randomly. However, chemistry is complicated so I’m going to use a metaphor of building objects that we live in. To make things hopefully simpler I’m going to add two characters. Character one is the Administrator – I’ll call her Lore. Lore is responsible for the growth of the building. Lore looks after the instructions. Character Two is the Engineer – I’ll call him Ed. Ed is responsible for the running of the Engine, taking in materials, energy, and oxygen to grow the thing we are living in and maintaining the boundary. Lore and Ed both sit in the middle of the building to begin with.

Level 1 – Type of Life: Adsorption | Object: Camping Tent

We start with a camping tent. Inside the tent Lore has given Ed the instructions to simply build bigger. Ed can stitch materials from around the tent that are stuck to the outside of the tent making more tent. After a short period Ed has used all the materials from around the tent and can’t grow the tent anymore as he can’t get hold of any more material close by. At this point the tent stops growing as both Lore and Ed can’t build any more.

I know what you’re thinking as you’re smart. This wouldn’t happen. As the tent expanded it would come across new materials that would expand it outwards until it reached the edge of the materials. And you are right – the tent in theory could get bigger to this point. However as the tent grows we introduce a few problems.

1. The ability to move materials from the outside to the inside – Ed and Lore are situated in the middle of the tent so moving material in and then out again is a challenge the bigger the tent becomes to the point where it requires a lot of energy in transporting things around.
2. The by-products of building start to build up – as new material is added this creates unwanted waste materials. Let’s be kind and call these off-cuts of materials that jam up the machine (in reality these are waste products that are toxic to be held in the tent).
3. Communication between what to build takes longer – as the tent grows the distance between Lore’s instructions and Ed’s construction increases. This takes time and messages may be confused.
4. Building and repair becomes challenging – as the tent gets bigger it starts to wear and needs repairing. The bigger the tent the more materials just needed to keep things working by keeping the barrier intact.

This is what stationary cells do. They adsorb materials in their near vicinity until the material are used up and when the balance between sustaining the cell and growing the cell is in balance. The cell is pretty small and boring as it just lets life happen to it.

Level 2 – Type of Life: Splitting | Object: two tents

With the tent limited in size due to the reasons explained above there a few choices on how to get bigger. In the spirit of keeping things simple and moving Lore decides to write a new set of instructions that allow the tent to split in half when it reaches it’s maximum size. This is a considerable step as the instructions not only show how to split the tent but also how to create copies of both Lore and Ed to live in the new tent that will be half the size of the maximum size tent. We now have a tent that will split after it grows to a maximum size.

This is what bacteria and other cells do when they reach a maximise size – they split in a process called cell fission. Cells continue to do this until they reach the edge of any nutrients and they stop as there is no material to build further.

Level 3 – Type of Life: Moving | Object: Boat

Things start to get interesting now as Lore has written new instructions that allow Ed to build two new features: 1) material detector/sensor: these sense that tell Ed where material is when the tent bumps into them and, 2) to allow the tent to bump into things there is now a motor that spins a long narrow propellor. The tent has changed from one that is no longer fixed in position but can move towards new materials. In order to control this Lore instructs for a new character who tells the tent when they have detected materials and another character that changes the direction of the tent to point in the direction of the detection. Let’s call these characters Sensa and Moto.

In order to move through the watery environment changes are made to the tent transforming it into a boat with the senses at what we’ll now call the front and the motor and propellor at the back. For now we are a circular blob whizz around from sense point to sense point. This movement creates two new properties: 1) Direction – forwards and, 2) Orientation – a position relative to another position – front (anterior), back (posterior), top, even as a blob.

Level 4 – Type of Life: Eating | Object: vaccum cleaner

With our capability to move forward we now have to build from the front as that is where the material is found. This is not great as it slows us down as we have to go, build, go, build cycle. Lore brings three new instructions to help: 1) change shape to be tube like rather than a blob – this will help movement through the water as it’s more fluid dynamic, 2) at the now anterior end a concave structure that has greater surface area to bring in more materials as we swim through them and, 3) an change to the engine that not only makes more materials for growth but also can transport materials through out tube like structure and expel waste by-products. In affect we can move through material hoovering up materials and expelling them as we go.

This adaption makes us more efficient and allows us to grow to a point but as we get longer and thinner communication between Sensa at the front and Moto at the back become difficult. Also the amount that we could adsorb at the front is less than when we were stationary due to a reduction in surface area. How do we get bigger?

Level 5 – Type of Life: Multi-uni-cellular | Object: Tube

We now have two key capabilities that will super charge our growing – division and movement. Our problem at the moment is surface area to absorb materials; we need to increase the relative surface area to volume and to do that we go multi-ball!

Lore writes an instruction that is super complicated as it involves coordination sticking other objects together in a stable formation all in the correct orientation. The result is six long combine harvestors formed into a tube allowing more materials to be absorbed through the middle and waste to be removed as we travel. We can get pretty big now and this going to cause more challenges for growth.

In cellular terms we are now simple-complex. We have multiple cells stuck together with are largely independent but benefit from being together. Each cell has all it needs and the ability to stick to two other cells so the motors are at one end and the senses are at the other. This configuration allows the tube to sit in a stream of nutrients and hover them up say for example in a hydrothermal vent in the deep ocean. Organisms here can grow very big they just need to attach to the vent and grow.

Level 6 – Type of Life: Cross-cellular | Model: ???

Things now are pretty complex with lots of instructions, lots of building, lots of sensing and lots of motoring. The next stage is to make the cells communicate with each other as we have got to stage where conditions on one side of the tube can be different to the other. For example whilst wondering around hovering stuff up one side becomes too hot which affects the working of that side or more materials appears to the front left and a quick turn is needed. To cope with this Lore adds more instructions that adds another another level of feature that allows for each tube to communicate with it’s neighbour by sending a message through the boundary. When the message is received the neighbour changes shape from being long and thin to short and fat. This contracts the tube and turns the tube in the direction of the contraction. As this results in being more effect at finding materials as we can detect and move more efficiently.

More instructions code for more messages and responses.More messages can be sent from one tube to another to change shape or other properties. Other properties like growing outside ways to stick to something or grow out finger like structures to increase surface area even further. As more messages are used across boundaries things get very interesting as the we can now not just react to the immediate environment but also develop differently as we grow: we can be fast to begin and then grow out – signals can be used to change shapes depending on both immediate circumstance and long term growth goals.

Level 7: Type of Life: Cross-instructional | Model:

So far Lore has been working very hard to create new instruction for everything needed in to build the model. Ed has been just as busy taking the instructions from Lore and building the new things she has asked for. Hard work. Slow work. Objects split and grow sucking up materials until we run out of materials.

This all changes when Lore comes across a different model adminstrated by Enzo. Enzo has an Ed, a Sensa and a Moto with six cells like Lore’s model but it isn’t a tube – it’s a six pointed star! Enzo’s world has develop so the single tubes didn’t align into a large tube but into a star formation where 6 cells had formed into one central core where all the messaging goes through a centre with each ‘arm’ having a Sensa and a Moto working with the other arms to move in a coordinated directions through messages passed through the core.

In a process that don’t require any details Lore and Enzo come together to share their instructions. The sharing of instructions rapidly changes the model into something new which is tube with 6 legs spread across the tube and central core in the middle. This model can now move quicker and take in more materials.

Level 8: Type of Life: Electrical | Model: Computer

But there is a big problem. How to coordinate all these parts? The message system currently is too slow as messages are made, transported, read, and responded to. With the new combined model, the administrator (now named Lorenza) introduces a new feature that is super cool and one that we’re been using to drive the motor: electrical signal (I’ll differentiate message to mean a chemical signal and signal to mean an electrical signal)

The way the signal works is surprisingly simple. The model pumps out positive charge from the inside to the outside through the barrier. This creates an electrical potential difference like a battery. When a message is needed to quickly go around the model the electrical charge travels around the outside until it reaches it’s designed target which then releases a message that does something to that part of the model.

With a rapid electrical system to transfer signals from the edges of the model to a central place to pass them on we reach the end of our journey of development. Clearly, there is more to this from a biological point of view but it will set the scene for how really complex animals develop their electrical or nervous systems to first coordinate themselves through to complex computation and thought.