06 June 2017

The Illusion of Choice Part Two: Evolution Is Not "Just" a Theory

            Welcome back to everything that ever was and will be. When we left off, we had just generalized the entirety of the universe to matter interacting in space. Great! Now, let’s take a look at how those interactions got us from rocks to cats. In case you didn’t read the title, here is a hint. It happened primarily through evolution. I would like to take a moment now, to go on a little rant about anyone who has ever uttered the phrase evolution is just a theory, because such individuals are so ignorant to the definition of a scientific theory that I can only imagine they need be told what it means before they immediately and abruptly change their mind.
A scientific theory is based on substantial evidence and might in fact be the only reasonable proposition for a particular phenomenon presently known. Such uncontested theories could even be generally accepted as truth, as there seems little probability of new evidence ever contradicting them. Let me hammer this in even more by naming a few “theories.” Gravity, plate tectonics, and Newton’s laws of motion are all scientific theories. Sure, maybe special relativity has a few holes in it, particularly when you try to fit it to the current model of quantum physics, but do not try to tell me Newtonian physics are just a theory and that we can’t really be sure if friction is even a thing. The problem, I believe, comes from people not understanding the difference between scientific theory and scientific fact. The latter does not actually exist. Scientists deal in evidence, not facts. The very nature of science, is that it can be changed at any point in time by the introduction of new evidence. This holds true for evolution as well, but currently no such evidence would even suggest a plausible alternative.
Okay, rant over. Let’s talk about evolution. I would hope that at this point everyone would know the general principles underlying evolution. Organisms develop different traits through pure happenstance from spontaneous genetic mutations. When such traits provide an advantage for the survival and reproduction of that organism, it increases the statistical probability that its mutated genes will persist. Over very long periods of time these small differences can have significant impacts on the number of organisms that either do or do not possess a certain mutation. Again, over very long periods of time these slight changes will add up and eventually create undeniable distinctions in species. While the differences between some species might be slight and arguably insignificant, there is no denying that cats are distinct from the western lowland gorilla.
That’s the basics of it. Let’s go over some of the aspects that commonly trip people up. There is an all too common misconception about evolution, that humans evolved from monkeys. That is absolutely not true, and really doesn’t even make sense. Evolution is not linear, it’s branching, like a tree. Humans and monkeys share a common ancestor, as do most all species. It is certainly possible that some simultaneous evolution occurred, but this would still go clear back to single celled organisms that happened to develop independently of each other. Another misconception is that humans are the pinnacle of evolution. Just like there is no last branch on a living tree, each species alive today is the most evolved of their kind. This also means that humans will certainly continue to evolve over the years and will eventually become distinct enough from present day humans to be considered a different species. Humans living in different conditions could even branch off to form more than one different species each sharing the common Homo sapiens ancestor.
When did it all begin though. It is fairly easy to picture evolution between closer relatives, and even possible to see it on a very small scale. Imagining something as complicated as animals coming from nonliving matter, however, is a little harder to wrap your head around. This is, of course, a big jump that occurred over millennia. We cannot forget the many steps in between. You can follow more complicated animals back to simpler animals and very simple macroorganisms to microorganisms. The jump from single celled to multicellular organisms was hugely impactful, but not too hard to believe, in hindsight, what with the development of cell walls and compartmentalization. The jump from nonliving to single celled organisms is the real kicker. This is where life as we know it comes into existence. Thinking about it, one might imagine getting something from nothing, but you must remember what life actually is.
Time for a quick biochemistry lesson. Atoms bind together to form molecules. A few examples include phosphates, nitrogenous bases, and monosaccharides also known as simple sugars. None of these are living things, cells, or even appreciable components of such. It would not be beyond belief for them to spontaneously form from water and carbon, nitrogen, and phosphorous compounds in the presence of energy (lightning for instance). So, one time in a billion years, lightning happens to strike a puddle of water, and everything is just right to form some of these chemical compounds. It was bound to happen eventually.
Well, as it turns out, these chemical compounds are the components of ribonucleic and deoxyribonucleic acids (RNA and DNA). You might recognize these compounds as those that encode and initiate the synthesis of proteins as well as self-replicate. It may not seem like much, but really that is all you need. RNA or DNA forms spontaneously by chance, and replication takes over from there. That is life. The first living organism is theorized to have been a single loop of either RNA or DNA free floating within a cell. Everything else, as they say, is history. Evolution took its course and a few billion years later we have cats roaming the earth.
That is how life got here. Humans, though, are a separate beast. Animals developed this thing known as consciousness, and that has made us slightly different from other living organisms. Some animals took it a step farther and developed a sense of self-awareness, an ability to recognize one’s own consciousness and distinction from the environment. Humans took that and ran with it developing communication to such a degree that two individuals can express and understand abstract concepts through an indirect medium, as I am attempting to do right now with you. We will explore this fascinating and complex development in depth next week.


-AMS

1 comment:

  1. See here is my issue... At the end of paragraph 6 you say that all of this random and spontaneous stuff was "bound to happen eventually". I have a hard time agreeing with that.

    The odds of events like that taking place at any given time are extremely small. I don't mean like 0.01% chance, I mean like 10^-100 or some incalculable and unfathomably small number. Now, if the history of time was infinite, then I would agree, it was bound to happen. If there is any chance of some event happening, it WILL happen over an infinite number of years.

    The problem is that time is not infinite. This is the conclusion Einstein came to, and is well-received by both theists and atheist (creation vs. big bang). So even if the earth is as old as scientists believe, roughly 4.5 billion years, that is still not even close to enough time to say that these extremely improbable events were bound to happen. Was it possible that it happened that way? Sure. But I would not conclude that this was bound to happen and is the only plausible scenario.

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