The Judeo-Christian-Islamic view of life is that some deity created all life – plant, animal, human – and set them to multiplying etc.
Every culture has a more or less thrilling and entertaining creation story, but somehow, life began with an already living deity passing on some spark. Like striking a match or shooting off a bolt of lightning, I guess.
Inanimate matter becomes living, breathing, moving.
Life, it seems, is something special, something sacred, something divine.
Except it isn’t.
We have words for life and a life force. Prana, for example, is the Sanskrit word for vital energy, often translated as “breath”.
But there is more to life than breath, which is nothing more than the movement of air in and out of the body. Sure, the air carries oxygen, and carbon dioxide is expelled, but there’s no magic in that. Just chemistry. We know the process, right down to the way the two gases are exchanged in and out of the bloodstream in the lungs. It’s just chemistry and a bit of engineering.
Let’s do a thought experiment. Let’s create life from inanimate chemicals. Let me know where the divine spark of life makes an appearance, will you?
Imagine a sufficiently fine-grained 3D printer. One that operates down to the atomic level. Let’s feed in some basic elements – hydrogen, oxygen, nitrogen, phosphorus, carbon – and make some DNA. All we are doing is arranging lifeless atoms into a simple repetitive structure, much like making something out of lego blocks, except a bit smaller.
We know the exact mechanics of DNA structure and replication. It’s high school science nowadays. DNA is made up of nucleotides, moderately complex molecules constructed of the simple inexpensive elements noted above. Just assemble nucleotide molecules, put them together in the right order, and we have DNA: the genetic information which determines whether a lifeform is a worm or a bear or a shark or a dinosaur.
We know the structure and sequence of DNA for various creatures. Let’s build some with our notional 3D printer. Add in a bunch of spare nucleotides and some enzymes – and the enzymes aren’t alive, they are just specialised molecules, just chemistry – and the strands of DNA will replicate themselves.
There’s no directing intelligence, no guiding hand. It’s nothing but molecules made up of simple atoms rearranging themselves according to simple rules. Do a bit of cooking, and you are doing the same things. Is it the spark of life? No. It’s boiling an egg or flipping a patty or caramelising onions. We’re making a hamburger, not Frankenstein.
Now, replicating DNA is one thing, but it isn’t cell division, and we need cell division to build a body. Again, it is nothing but engineering and chemistry. More complex than DNA replication, to be sure, but there is nothing startling about it. Given the right conditions and nutrients, cells divide all by themselves.
So let’s 3-D print a cell out of basic elements, include the DNA, and set it going.
Aha! “Set it going”. There’s your spark of life!
Well, no. Chemical reactions don’t need anything special to start running. What are you doing when you melt ice, or boil an egg? Just adding heat. Given a hot enough day, eggs will fry themselves.
All we need to set a DNA replication going is DNA and the right enzyme. If they are present along with enough nucleotides, then the thing happens by itself. Likewise with the various cell mechanisms including duplication. Set up the right conditions, including the various molecules in the right structures, and they work all by themselves. Can’t stop them, really, any more than you can stop an egg frying on a hot plate, or water freezing on a frosty day.
What we need to grow a single cell into a living creature is more engineering. Think of all the plumbing and structures that we need to make a human being out of a fertilised egg. Do we need all that?
Let’s start simple. Let’s get a chicken egg – and nobody is going to call a dozen eggs in the supermarket alive – slot in the chicken cell we’ve printed and watch what happens when we keep it warm.
It doesn’t even need to be perfect. Just good enough to set the process going. The DNA coding determines what sort of creature is going to be constructed, and the simple processes of chemistry will follow the pattern encoded to create molecules which will self-assemble into cells and divide into fresh ones, each perfect, each a tiny building block of a chicken.
At no point is there any “spark of life”. The 3-D printer assembles the initial DNA and cell, the egg does nothing more than supply nutrients, we add in enough heat and oxygen to keep the developing chick warm, and voila; three weeks later we have a new chicken and if we get two or more of them, we can keep the process going indefinitely.
Thought experiment? Maybe. But just you read the science papers and at some point it becomes real.
There’s no spark of life or life force in us. Science cannot find any more than chemistry and electricity. In complex arrangements, to be sure, but complexity does not equal a life force, any more than the enormous complexity of a fighter aircraft or a naval destroyer makes the inanimate assembly alive.
Just because we have words for things and concepts, that doesn’t make them into items in the material world. It makes them into words, and we imagine in our brains the things they represent.
As you, dear reader, have just done by reading these words, which are no more than electrical or magnetic charges transformed into glowing pixels on your screen. No chickens, no DNA, no jumbo jets involved. Just imagination.
We imagine life and a life force. Simple as that.