The Basic Building Blocks of Life: My Analogy for Evolution
The origins of life on planet Earth is a fascinating subject. Ask yourself this question: how did the basic elements and chemicals that enrich our planet ultimately become the life we know on Earth today?
My analogy for evolution, called The Basic Building Blocks of Life, is designed to help illustrate how the basic principles of evolution can be applied to very simple systems. We’ll show that, given a few basic principles, what start off as simple blocks will evolve into more complex systems through similar ways to how elements and molecules could have evolved on Earth. From simple chemistry to life; let’s dive in!
To build our analogy we must define our world. This is a very simple world where there are magnetic blocks that have the ability to connect to one another. Blocks can connect their red sides to another block’s blue side. Like magnets, two same-colored sides would repel each other. Blocks can have red and blue sides in different arrangements, allowing for complex shapes to be formed when the blocks are connected.
In our world, lone blocks don’t last long! The Sun’s energy burns down upon them with unfiltered radiation, blasting them into nothingness. To survive, the blocks must group together and become something bigger and better.
Much like how different molecules on Earth can have vastly different properties, unique block combinations show a wide range of properties as well. Stacks of three blocks will act differently than stacks of four blocks. Blocks in an “L” shape react with other blocks differently than configurations in a “T” shape. This is analogous to how chemistry actually works. For example, water (H2O) and hydrogen peroxide (H2O2) are almost identical in composition but yield very different properties.
Now that we have a mental picture of this simple, block-ridden world, we can break down the fundamental properties of evolution. By understanding the basic principles we can begin to see how the simple building blocks of life can evolve into more complex systems. The principles we’re going to cover are energy, randomness, survival, and replication.
In order for a system to evolve, pieces within that system must be able to move. In order for things to move, they require energy. While the motion can technically be at any speed, such as slow moving plate tectonics, faster motion will help things evolve faster. One of the reasons that water is such a great facilitator for life on Earth is that it allows for a lot of fluid motion. Water, in its liquid or gaseous form, is very good at dispersing energy. Energy from the Sun and from the Earth’s core move water around. This movement, caused by the changing of densities and pressures, is critical for life formation since the movement instigates the mixing and combining of various chemicals.
Our simple building blocks are no different, if there was no energy to help move them around they would never have the chance to connect and make more interesting shapes. A cold, dead, motionless world is not going to evolve.
Reality is inherently random, which is great for evolution. Combining randomness with motion can yield some surprisingly ordered results, including creating something complex from something simple. Imagine a set of blocks whose motion is fixed (not random), oscillating back and forth next to each other for all eternity.
Combining randomness with motion can yield some surprisingly ordered results, including creating something complex from something simple.
Not very exciting. Without some randomness to spice things up evolution would not be possible; things would just follow their predefined paths and never go down the road less travelled which leads to exciting new possibilities that are unimaginable in a world with only fixed motions.
Survival of the Fittest
If evolution could have one defining feature it would be survival of the fittest. This concept is not only applicable to macro-sized animals where one needs to kill the other to survive, it also applies to the tiniest of systems. In our analogy we define that the more blocks that are stacked together the longer they will survive. Given random motion and enough time there would be lots of three-block stacks, four-block stacks, and probably some five and six-block stacks. These longer and longer stacks of blocks will connect to become “stronger” and build more and more complex systems. The random stacks of blocks that can live longest in their dangerous environments will be the ones to go on and possibly replicate.
Surviving is great, but no individual system can reasonably be expected to survive forever. In order for something to truly survive on a planet as dangerous as earth, the evolving system needs the ability to replicate its information. It’s great if a 500-block megastructure can survive a glacial ice-age, but eventually it will get destroyed by something, perhaps by a 6km wide meteor, and if it does not have the ability to replicate then it will be destroyed forever, never to be seen or heard from again in the remaining lifespan of the Universe. Yikes!
The best chance anything has for longterm survival is to replicate itself. Survival of the fittest does not only refer to the survival of individuals. It’s more about survival of the information that defines the system. Modern life on earth has evolved using DNA as the common surviving bit of information. Our analogy using the Building Blocks of Life has the fabled twenty-block hypercube.
The hybercube block configuration has a very special property: it can turn other groups of twenty blocks into a hypercube shape as well. By doing that, this block configuration will continue to replicate and yield more and more hypercube shapes. In time, these shapes may turn into an even more stable and complex system, such as the hundred-block megacube, which has the unique ability to protect other hypercubes nested within it from destruction.
Given even more time, motion, and randomness, when a thousand megacubes combine, a new block configuration is born: the omegacube. These omegacubes can replicate and spawn additional megacubes. Randomness also plays a very important role when systems are replicating. For example, a system that can replicate with slight variation, such that each offspring is unique, will evolve quicker. This is due to the random survival advantages that some of the offspring will have. If our omegacube structure is spawning slightly varied megacubes then maybe some of those new structures will be able to survive longer and make new, better combinations.
You get the point. The block configuration can continue to get more and more complex if they have the ability to replicate their information. The system will evolve even quicker if the replicated systems can have variations.
Evolution doesn’t happen overnight. In fact, it’s one of the slowest and most complex processes that exist on earth, taking billions of years to get to where we are today. For some insights into how complex life has evolved, one of the most basic organisms we know of, a single-celled bacteria called Mycoplasma genitalium, could be partially simulated by using 128 computers which needed to run for 9 to 10 hours and generated a half-gigabyte of data; and that’s just a very basic, single cell.
In comparison to our humble block analogy, that would be equivalent to the cell being composed of a hundred million blocks in thousands of different configurations which work perfectly together to create the different parts of the cell. In reality, that’s all that a cell is: billions of molecules making up hundreds of small, individual systems that work together to keep the cell alive and help it replicate.
Millions of blocks are not going to magically become a cell overnight. Cells are incredibly complex and took nearly a billion years to evolve. However, parts of the cell could begin to evolve from raw materials particularly quickly, such as the cell membrane, which could have started as a simple chemical structure that had the ability to protect the contents of whatever was within.
So, how did life evolve from simple chemistry on earth? Energy, randomness, survival, replication and time. With those simple processes, all of which are wonderfully abundant on our ever changing planet, what started as simple elements and molecules became the life we know and are today over three and a half billion years.
I find this absolutely fascinating and utterly humbling. At this point in time we don’t know if there’s any other intelligent life in the universe. There’s a very real chance that we are the only life that has been able to evolve to intelligence and consciousness and are still alive today. Our planet may be one of a hundred billion-billion planets that could sustain evolution successfully for billions of years to get to where we are today. The DNA that’s inside you, me, and every other life form on earth has survived glacial ice ages, global warmings, asteroid impacts, volcanic apocalypses, and a thousand other world-altering events.
If that is so, then the humans that are alive today are possibly the most complex and amazing creatures that exist in the entire universe.
You may feel a bit small and unimportant at times, but know that you are special, and I mean really special. You are unique and completely one of a kind. It’s taken nearly four billion years for you to show up and read this, and I find that amazing!
— C.C. Edgar