Amino acids are rather complex, and anything complex is fairly unlikely. Then again, solar systems and galaxies, water and rock cycles, and particle physics are all magnificently complex too, and they all happen to exist. Even just within inorganic chemistry, plenty of naturally, randomly occurring compounds are more complex than amino acids.
Its very uncommon, but it has been found that, under just the right circumstances, amino acids can form spontaneously. Just the right mix of carbon and nitrogen, some oxygen and hydrogen, maybe just a touch of sulfur, make it all aqueous (dissolve it in water, so they can all move around) and maybe zap it with a bit of that proverbial lightning for good measure - at this point it is still nothing more than an ordinary chemical reaction - and you got yourself one of the fundamental building blocks of life.
We know the end of the story, but considered alone there is nothing especially special about some random amino acids floating around in puddles. Just about everything is made of compounds (two or more elements mixed together), not-particularly-sexy things like rocks and dust and air and water. Some have more different elements mixed together than others.
Granite is made of several compounds, (quartz, mica, and feldspar), themselves made up of combinations of oxygen, silicon, aluminum, iron, magnesium, potassium, calcium, sodium along with trace amounts of other elements. It makes up the vast majority of the surface of the Earth, (there is somewhere on the order of 20 billion times more of it than there is of all living things on the planet - plants animals, bacteria, everything combined)
In comparison with granite's 8+ elements, amino acid's 4 seems almost simple, and compared to its abundance, amino acids are downright insignificant.
Out of context, they don't seem like much to get excited about. But then some of them started interacting with each other, and forming bigger, more complex molecules. Proteins. And for reasons the world may never know, one or some of them formed a very special kind of protein-like molecule that we refer to today as deoxy-ribose nucleic acid (except that that name wouldn't have made any sense at the time, seeing as it wasn't in the nucleus of anything - there was nothing to be inside of, cells hadn't been invented yet!). Of all the random collections of elements floating around, this one had the peculiar and rare property that, by sheer virtue of its chemical structure, each part of it happened to attract a corresponding equal but opposite part to it. This was certainly not unprecedented in the natural world of physics; magnets, for example, naturally attract other like-minded but opposite elements to itself. Since it was floating around in oceanic soup, there were plenty of pieces of amino acid around to attract, and as it did, they formed a pattern that matched that of the DNA string. Again, uncommon but not unheard of. Put a stick in a glass of hot sugar water, maybe with a dash of food coloring for fun, and you can watch molecular self-replication in action (and end up with a tasty rock candy on a stick as a bonus!). Any crystal, in the presence of a super-saturated aqueous solution containing its own constituent molecules, will attract said molecules to itself, and prompt them to arrange themselves in the same pattern as the crystal itself already has. You can think of DNA as a sort of soft crystal, with an unusually complex pattern.
None of this was particularly good nor bad, and probably not the least bit interesting, (if there had been anyone around to either be interested or not). It just was, just the way Jupiter endlessly circles around the sun, not for any good purpose, but just because, what else is it gonna do? It could go flying off, but then it wouldn't be there for me to comment on, and I'd be using something else as an example. But I'm not, so clearly it didn't, and here we are.
All this jumble of amino acids and DNA and proteins is just following the basic laws of chemistry, seeming at first glance to defy the laws of entropy with its complexity but remember, its all getting stirred up by the sun, and just a tiny fraction of it's energy is going into order, so the laws of physics are obeyed, and the universe does not collapse into itself in protest. The universe doesn't even notice.
Most of these little bits of proto-protein aren't doing anything. They form, they float around, some of them cause their own pattern to be replicated, and then they get broken up by a strong bit of current or UV sunlight or a falling pebble or whatever, and the broken pieces get incorporated into some other molecule. And by most I mean the vast majority, practically all of them. Except for one or two or a few dozen that happen to fall into a pattern where when it builds a duplicate of itself, and then that duplicate forms a duplicate, it ends up building something else, something with some other properties than the original had, and whose property just happens to have the effect of causing that original molecule to last a little longer before it gets destroyed. And now all of a sudden the whole game had changed, because things aren't happening by chance anymore. The fact that the protein this bit of DNA builds prevents the DNA from being destroyed quite so quickly kickstarts the process we know as "natural selection" way back then, back before there is even anything which we would call "life". We are still talking random chemical reactions among basic elements, but now the strand of DNA which happens to build the more useful protein is more likely to exist long enough to create more copies of itself, so it will come to be more common than the ones that just build random useless protein. Given enough time of random trial and error, some could create various different molecules that had various features due to their particular shape, much like you can build anything you can come up with with just a couple shapes and colors of Lego. Since its all just floating around and nothing is keeping anyone separate, different strands of DNA may bump into each other, and stick together, thereby combining their creations, "working together" as it were; although its important not to anthropomorphize these bits of carbon, nitrogen, oxygen and hydrogen - they no more had a goal than those sugar molecules have the goal of making you candy on a stick, or than a bit of feldspar has of being part of a continent. These are just things that happen... Eventually at some point somebody came up with lipids (fancy science word for fat molecule) which paved the way for a bi-lipid membrane, and now things finally start to get interesting, because if one of these bits of carbon and nitrogen, some oxygen and hydrogen and just a touch of sulfur that generates copies of itself when in a solution of similar molecules and ultimately create proteins that do something that prolongs the existence of itself, which has joined up with several other similar bits but which create different proteins if this whole thing generates enough of this bi-lipid stuff, and it spreads out and surrounds the DNA, until the bi-lipid membrane comes all the way around and meets itself on the other end, so that the DNA is completely enclosed within it, well now you basically got yourself the fundamentals of a cell.
This means that stuff won't change as quickly, as the DNA is isolated from other DNA that may have interesting stuff going on. This slows down new useful protein inventions, but it also keeps out a whole lot of crap, and it protects the DNA from the environment. Which is important, because the absolutely perfect combination of water and sun and chemicals that spawned the first activity can't last forever, and outside of absolutely perfect conditions the DNA dries up or gets burned by the sun or broken by a falling bit of rock or some other random crap. When its covered, the covering protects it from all that, and when cosmic forces cause environmental conditions to change, any DNA which had come up with this "cell membrane" trick survives, while everything else is erased and broken down to nothingness just as randomly and meaninglessly as it was first created. If the cell membrane wasn't created in time, then all of them would have been stirred back into the pot, and the story would have ended there.
At this point its still debatable if what I'm describing can be called "alive" or not, but it is certainly getting very close. So lets just go ahead and gloss over approximately a billion years of refinement and skip ahead to fully formed bacteria. These things are amazing. They have whole separate structures - "polyhedral organelles" - that perform specific functions, they use various organic or inorganic compounds or even sunlight to turn ADP into ATP which is then used to provide energy for growth and metabolism and even moving around from one place to another. They can "sense" things, in a sense - again, its vital not to anthropomorphize; they don't "want" energy or to reproduce or anything else, nor do they have any ind of awareness of... well of anything, including their own existence - in that certain structures have developed on the cell membrane which react to various stimuli. Produce chemical X when encountering a concentration of ___% of chemical blah blah. Inside other things have a set response to the production of that chemical, and the end result is the cell swims this way or that in response to concentration gradients. Its all a system of IF xxxxxx is true, THEN do yyyyyyy. Basically a tiny little soft robot. A robot who's programming says to acquire energy, grow, and once a certain size is reached, split in half into two equal copies. Eventually, just as independent strands of DNA (genes) joined forces to make bigger more complex genomes, eventually cells themselves started sticking together (literally and figuratively) and creating larger independent units, organisms, all following their own instructions, which has them working together to the same basic goals of survival, finding and ingesting food, and reproducing. That reproducing part means that there keeps being more and more of them, as each generation there are twice as many as last generation, just as there would be if robots were roaming around with coding that said for each one to build another robot which had coding to build another robot. In each new generation there is a chance that there will be a mistake in the copying of the DNA. These mistakes will normally be irrelevant, since much of the DNA is random junk that doesn't really do much, and when they aren't, they will cause problems, as important things won't get made properly, and life is a delicate balance. Those who have bad mistakes die, and that's that. Every once in a very great while the mistake just happens to do something useful, and evolution proceeds. Little by little the cells become more complex, and therefor more efficient and/or more able to handle varying environmental conditions.
Since these simple organisms can react to their environment, and some since you can say they can sense. As they will actively engage in behaviors that lead to survival, you could say that they have goals. But they don't think, they don't feel, they don't want. They don't want to live, or to eat, or to reproduce. They just do things. They are just like the sugar crystals. Pretty much just basic chemistry, following the laws of physics, only very, very complex.
This is enough to explain all bacteria, fungi, plants, and the very simplest of animals, like jellyfish, starfish, sea anemones, and sea cucumbers.
And if you have a basic background in biology, none of this is the least bit surprising or even new information. This is all stuff that has been well understood, in much much greater detail than I have spelled out, for a pretty long time. Here is just a brief summary of one process, animated down to the molecular level:
The use, duplication, or distribution of this material for any commercial purpose is strictly prohibited
All of that is going on inside many of your 50-100 trillion cells, right this moment.
Evolution can explain life just fine. If you want a whole lot more detail, I highly recommend Richard Dawkin's "The Selfish Gene".
None of that is the Last Big Question.
Many a philosopher, religious person, and even scientist, understanding the mechanics of life, is still left wondering how it is that we not only exist, but we know we exist. Is a plant any different from a rock in terms of self-awareness? Probably not. But we know, because we think, therefore we are. We have something extra. Something intangible. What religions refer to as the soul. The essence of what makes us what we think of ourselves as.
We think, we feel.
How can evolutionary biology, which is really just complex applied molecular biology, which itself is just complex applied chemistry (which itself is just complex applied physics) explain something as ephemeral and wondrous as awareness?
The standard way to deal with this question is to simply throw in the towel with the answer "it can't" and be done with it, or to say this hasn't been answered... yet... and still call it a day.
But I have an alternative proposal.
I propose we already have the tools to understand it.
Back to my story...
Having no more than biochemical feedback responses does the job just fine if you are a single asexually reproducing creature floating around in the world, just finding food and not doing much else in life.
At some point, though, a creature and its progeny tried dividing the task of reproduction up between two separate individuals and that caught on in a big way, because it meant that evolution could proceed much more directly toward useful changes, rather than the strictly trial and error (mostly error) mutations of evolution up until then. Not that these collections of cells particularly wanted to evolve, or even to survive, per say - its just that those that didn't develop in the direction of survival, didn't survive, and so there is nothing left of them. If you happen to be a plant, all you need do is throw some sex cells to the wind and "hope" for the best (I just can't seem to get away from these anthropomorphic terms, can I?). If you have the power of locomotion though, this suddenly makes life a lot more complicated. Where the world was once divided up into "potential food / not potential food", it now has to include recognition of what is your same specie, and therefor a potential mate. In addition, with locomotion comes the ability to evade that which sees you as potential food, so there is reason to recognize potential predators as well. Detecting chemical concentrations (i.e. "smell"), and basic touch receptors can help with those tasks, but it isn't precise enough on its own. Enter eyes and ears.
Now simple chemical receptor feedback organs are not enough to process all of the information accessible to our rapidly evolving sacks of amino acids we call "animals". Having an organ dedicated purely to information processing becomes worth all the extra energy and vulnerability that goes along with having it. But having a central information processing center does not necessarily imply having consciousness. A Commodore-64 or RadioShack TRS-80 had centralized information processing units (or CPU), but it doesn't mean they had self-awareness or feelings.
At the level of insect, life is complex enough to require dedicated data processing, but life is no more complicated than what we could program a robot to do back in the 1990s.
The digger wasp has a complicated set of steps it goes through to make life as easy as possible for the next generation.
After finding a mate, and successfully mating, the female then searches for a suitable nest, and having found one, then finds a delicious insect that her babies can eat once they hatch, maybe a bee or a cricket. Instead of killing it, she sets her stinger to "stun" so that it will be fresh once the kids are ready for their first breakfast. She drags it back to the nest site by its antenna, and then leaves it, alive but totally paralyzed, just at the entrance to the nest while she goes inside to look around, inspect it for safety, maybe clean up a little, and, if everything checks out, she retrieves the living breakfast, drags it inside by its antenna, lays eggs inside, comes out, and seals up the entrance to keep the breakfast in and predators out.
Its easy to look at this from our own human point of view, and think she must be thinking about actions and consequences, planning out steps, and executing them deliberately.
It tells a very different story though, when something doesn't go according to plan...
If, after the wasp comes out after the nest, a mischievous human comes along and, right in front of the watching wasp, disrupts the nest to a standard that would not have passed inspection, she will continue on regardless, dragging in the paralyzed prey and depositing the eggs. The "inspect nest" step has been completed, she she moves on to the next step. If, instead, the human waits until the insect is inside, and then reaches in and takes it back out and puts it right in front of the entrance, she will not retrieve it. She will lays eggs and seal up the entrance, right in front of the breakfast insect, which of course means the newly hatched young will starve to death without ever having had a chance to dig their way free. The "move insect inside nest" step has been completed.
If, during inspection a human moves the insect a couple inches away from the door, when she comes out, and, finding it missing, looks around. She finds it, and, again, drags it to the entrance. But when she gets there, she drops it again, and goes in to do the inspection over again. The instructions say "drag insect to just in front of door, then go inside to inspect". The fact that it was moved a few inches away resets that step. If, during the second inspection, someone moves it a few inches away again, she, upon finding it, will leave it at the door, and inspect a third time. She will do this indefinitely, until / unless she comes outside after inspection and finds the insect exactly where she left it, at the doorway.
If, instead of moving it, the human snips off the antenna, the wasp is stuck. Its per-programmed instructions say to drag prey by the antenna. They don't say anything about dragging it by a leg or mandible or any other contingency. So it will leave it there, and has to start the entire process of finding suitable prey over again.
This is the sort of behavior you would expect of a computer. It doesn't have any real goals, it just goes through the steps it was programmed with in order. It doesn't think about how to achieve any particular step, so it has to be spelled out in detail in the programming.
This is what we refer to as "instinct". It is more than just stimulus-response, as it can result in a complex set of behaviors, and not just a reaction to the conditions of the moment. It requires not just a central nervous system to collect sensory data, but a brain to process it all, as well as house the instructions. But it still doesn't require anything like what we know consciousness to be.
There are obvious drawbacks to the likelihood of survival to being an automaton. Sometimes things don't go according to plan. Sometimes the insect gets moved, or it is missing its antenna.
Sort of like the change from 2D linear video games to the "sandbox" type, having open-ended goals is a total sea-change from the old system.
There is an advantage to be gained by having just a general goal, and saying "engage in whatever behavior will lead toward this goal".
To do so requires not just the ability to interpret and enact behavioral instructions, it requires logic and deduction. It requires some degree of learning, which requires memory. It requires, in short, intelligence.
But that is only half the equation.
We can build a computer that has intelligence. In fact, technology has become so advanced that intelligent computers are already commonplace. Artificial intelligence is used to allow self-driving cars and planes to figure out on their own how to deal with changing conditions. Watson beat actual humans on Jeopardy, and Siri is basically a pared down Watson that nearly a quarter of Americans carry around in their pockets every day.
But we humans actively tell our computers their goals, even when they figure out how to achieve those goals on their own.
Imagine the worlds most intelligent super computer, with access to all the information on the internet and control over a highly articulated and mobile robot.
In countless sci-fi stories the robot decides to take over the world, or wants to become more human, or has some other unintended consequence, but much more realistically, a computer/robot with intelligence but no specific request from its programmer would just sit there, doing nothing, indefinitely.
It may know how to do just about anything, but it has no motivation. It has no reason to do anything, because it has no desire.
That is an absolutely vital component that is needed if you are going to have a system (whether biological or synthetic) actually go about the world doing things using open ended intelligence and logic. Even self-preservation is not particularly logical, unless you have already somehow established that existing is a "good" thing.
So, in addition to the intelligence to apply deduction and logic, simultaneously the qualities of pleasure and pain have to evolve, in order to ensure an individual organism uses those abilities to achieve the genes "goals" of self-preservation and reproduction. Again (I know I am repeating this a lot, but its important, because it is so hard for us, from our cultural perspective, to not think of things in terms of how they seem to us) the word "goal" is in quotes because it isn't a goal in the literal since. Its just that those genes which lead to building organisms that feel pleasure from things that tend to increases its chances of existing in the future are more likely to exist in the future, and those that don't (say, one that lead to feeling pain from sex, or pleasure from consuming bleach) die out quickly.
Pleasure and pain are our genes way of getting us to do the things that makes their own survival more likely, and to avoid those things that make it less likely. Sugar tastes "sweet" because it gets us to eat things that we can metabolize. Healthy creatures of our own specie but different gender look "sexy" in order to induce us to mate. Every value of something as good or bad, desirable or detestable, is created directly by our genes' building of our minds.
And now we get to the most crucial, pivotal part:
In order for the creature to experience pleasure or pain, there has to be some part that "experiences".
That part is what we call awareness / consciousness.
It is an inherently necessary part of having intelligence as a survival strategy. Without it, we, like the super computer, would just sit there, smart enough to build civilization, but with no motivation to do so.
Instinct doesn't require awareness, but it can't deal with as many types of problems.
Therefore, far from being an unexplainable part of evolution, consciousness may be a natural consequence of it.
It only seems amazing and wondrous and hard to come to terms with to us, from the inside - because we are programmed to think we are special. That's part of the self-replication goal programing itself. Drawing a distinction between life and non-life keeps us from obliterating the eco-sphere with nuclear missiles (not to mention keeping us from eating our children).
At this point we can probably explain many chordates (amphibians, reptiles, fish - but how the hell do I know what they experience?)
We've accounted for consciousness itself, finally, but there is still a little further to go.
It is now possible, with the invention of intelligence and pleasure / pain, to have individual problem solving, but its behavior is still limited to hedonistic feedback to the individual. This can, in fact, lead to things like eating ones own young, as some simpler chordates are occasionally known to do. There can be further advantages to coordinating behavior between multiple individuals of a specie. To do so as effectively as possible sometimes requires an individual going against their own best interest. Pleasure and pain can not induce altruistic behavior, which can sometimes be more beneficial for a gene's survival (more true the closer the individuals are related) than selfish behavior. A robot programmed with intelligence and the ability to feel would act, but it would be a sociopath. It wouldn't be immoral, but it would be amoral.
In order to manipulate an individual to act against its own best interests, evolution invented emotions.
Emotions are our genes way to get us to do what our genes want us to, even when they aren't in our best interests as an individual.
Almost all of our emotions - anger, loneliness, jealousy, pride, love - directly relate to interaction with other's of our own specie. If you stub your toe on a rock, most people don't get angry at the rock. The only emotions that don't deal with social interaction, which have relevance even when no one is around, are those such as fear or joy which can relate directly to physical hedonistic pleasures or pain.
-As an interesting side-note, notice that this theory suggests that intelligence must evolve before emotion, the opposite of what is frequently assumed. Emotion without the means to carry out steps to achieve a goal would be pointless.-
Now we can finally explain the behavior of birds and mammals and ourselves, as well as our subjective experience of existing. If we didn't experience it, there would be nothing to do the thinking, nor the feeling, and then there would be no means by which to apply our intelligence to problem solving to reach particular goals. We feel to direct our behavior toward particular things, including sometimes things which fail to maximize physical pleasure for ourselves as individuals. This is mainly manifested in situations where altruism benefits the group as a whole (i.e. other copies of a gene we share).
Charity and giving and being moral feels good to us for the same reason sugar tastes sweet: it gives us a goal which tends to increase the chances of survival of the human genome, and, ultimately, the genome of all living things, which for the most part is pretty much the same. How likely we are to care about a given specie (monkey, cat, frog, insect, plant) is in direct proportion to how many genes we share with it. We rationalize this is being related to how conscious it is...
(and I admit that I do think level of consciousness is a valid measure for making ethical decisions, and I still think it is entirely valid, although this isn't the place for that digression. I will elaborate on that some day; and hopefully I'll remember to come back and add a link to it here when I do)
...but ultimately it may be no more than an application of our own selfish genes prioritizing those lifeforms most likely to have copies of themselves inside. It happens to be very convenient that this so closely correlates to brain size and intelligence. Perhaps if ants had ethics, they would consider all arthropods more valuable than annelids or chordates, but less so than insects specifically. Perhaps they would eat worms without a second thought, but petition for the ethical treatment of aphids.
Point is, far from being evidence of a higher consciousness, our feeling of morality itself is easy to explain by ordinary evolution.And when you think about it that way, it can take not just the mystery, but some of the profoundness out of the whole thing.
If some being from another dimension came here, would they necessarily find anything more interesting about the complexity of amino acids than the complexity of the rock cycle? If they looked at bacteria, and they looked at us, would they necessarily see the same distinctions we do?
As individuals we have free will, but our will itself is determined by our genes, and collectively our behavior is exactly what would be expected of us. Any one person may choose not to reproduce, but overall we do, and that's enough to keep the human genome going.
I propose that from an outside perspective, if there could be one, we would just look like a colony of large ants. Like them, our collective behavior could be explained, ultimately, by physics.
Spirituality is applied psychology is applied sociology is applied biology is applied chemistry is applied physics.
None of this is to say that life is not wonderful. And valuable. As I alluded to earlier, I will explain the valuable comment in a future post. And that it is amazing and wonderful, well that doesn't need qualification. Because we aren't some neutral outside observer. We are us. And I mean, come on, just look around! Look at the first video in this post. Look at - freakin anything!!!!!!!! Look at your hands. Look at a building or a car sometime. Look at all this stuff that exists, much of what we created on purpose. Things we take for granted are, they are just, unbelievable! Look, understand where babies come from doesn't make sex less fun or pleasurable. Understanding calories and carbohydrates and the ADP/ATP cycle doesn't make ice cream any less delicious.
Consciousness may not be mysterious or improbable, but it is sure nice it exists. Because otherwise, nothing would be nice! There would be no such thing as niceness.
It may be the genes talking, but I am quite glad I have it.