Saturday, August 8, 2015

Evolution as Fact

The National Center for Science Education (NCSE) recently had a couple of posts (part 1 and part 2) on this subject, so I decided to repeat myself and add a few things on the subject of Evolution as Fact, Evolution as Theory and Evolution as Path.

Previously, and often, I have discussed Evolution as Fact and Evolution as Theory.  The Path element is something I hadn't really considered.  One of my issues when it comes to Creationists is they tend to treat them either as one in the same, or they tend to slip from one to the other without warning so the listener/reader doesn't understand the context of a comment.  It's like trying to hit a moving target.  While early on I thought they did they accidentally, but soon realized it was a tactic specifically designed to confuse people.

How often has someone said "How can evolution be a fact when it's just a theory?"  Sometimes it's coming from a Creationists, but also it comes from people who simply do not understand the difference and are honestly questioning it.  Frequently the comments comes from political figures who have some philosophical axe to grind.  In any event, it's important to understand the differences.

So let's start.  Is Evolution a Fact?  Yes!  But before trying to convince you, let me reiterate an old example.  Is Gravity a fact?  Yes!  To test it, drop something -- preferably nothing of value.  What happened?  It fell down, toward the mass of the Earth.  Without getting into the why it fell down, can we all acknowledge that it fell down?  There is your fact.  Facts are generally evidence of something happening, an occurrence, a happening.  The pencil you dropped fell down.  It's hard to argue fact.

So from the point of view of Evolution, is it a fact?  Looking at the evidence of life on this planet and the incredible changes it has undergone over long periods of time, yes Evolution is a fact. The evidence of biology, paleontology, biodiversity, comparative anatomy, to name a few, are factual pieces of evidence.  It is so factual that many creationists don't even bother to argue against the evidence -- which is why they try and confuse people by claiming fact and theory are somehow the opposite of each other or they create an imaginary line between what they call micro and macro evolution.

One thing I will say is that the Fact of Evolution cannot be tested quite as easily as dropping a pencil.  But that doesn't mean it cannot be tested.  Have a DNA test of yourself and a relative and you can see examples of evolution.  Look at the preponderance of evidence that's been collected for centuries.  Why is there no evidence of human beings before about 250,000 years ago?  Why do we see such geographical biodiversity?  Why do we have evidence of nearly every lineage of plants and animals changing over time?  Evolution is a fact and the facts of evolution deserve to be taught in science class.

Now, how about a Theory, is Evolution a Theory?  Yes again.  And using the same term to describe both a Fact and a Theory can be confusing, we do stuff like that all the time.  A recent Jeopardy question asked about a three-letter verb that applied to sports, the theater, and politics.  The answer was 'run', and the meaning of each usage was considerable different.  Seriously many of the words we use have multiple definitions depending on the context, so why is it so hard to grasp that with Evolution?  In reality it's not, unless you don't want to recognize it.

Like Gravity (fact), there is a scientific Theory of Gravity that explains why and how the fact occurred.  That's all a scientific theory is an explanation, but not just any explanation.  It's one that explains the available facts in the most accurate way possible.  Theories are not carved in stone, but fluid.  As we learn more, theories change and adjust based on our knowledge.  There are countless examples from Gravity from Newton to Einstein, just as there are countless examples within Evolutionary Theory, like from Darwin to Gould.  The explanation of the fact of Evolution is generally referred to as the Theory of Evolution.  Charles Darwin would probably not recognize much of the current theory, but he would recognize many of the underpinnings.  Fact and Theory, same term, but very different meanings.  The Scientific Theory of Evolution IS the best current explanation of the Fact of Evolution that we have.  It isn't an absolutely perfect and complete explanation, because there are things we do not know yet and the work continues.  But what we do know, what we can support with actual evidence, and the explanations we know of all fit within the current Theory.

As with Gravity, theories do change, but that is the strength of a scientific theory.  Various creationists try and paint that as a weakness.  But seriously, how many of you would like to get treated in accordance to the Miasma Theory as it existed in about 1850?   Yet when it comes to Evolution, so many people want to demolish 150+ years of science.  The problem is they do not want to destroy it because it's wrong, it's because they believe that it threatens their precious religious beliefs.  And one of the tactics they use is to confuse Fact, Theory, and Path!

Speaking of Path, the third way of looking at things is sorta new to me.  I hadn't given it much thought, but recent comments by folks like the Discovery Institute made this make perfect sense.  Aside from the Fact of Evolution and the Theory of Evolution, there is the detailed specific instance of how one structure over time because very different.  In other words what was the pathway that whales took from the sea to the land and back to the sea?  What was the path that took a injector to an outboard motor?  What was the path from our ape-like ancestor to human beings?  Here is where a lot of the modern work on evolution is occurring.  We might never know the exact path, but every day we are learning more and getting more evidence.    We speculate on potential paths and other scientists measure up how our probable path matches the available evidence.  Pieces and parts of ancient organisms are racked and stacked in order and as we learn more, re-racked and re-stacked, like archeopteryx for example.  Of course we will never please many people, especially those with a philosophical grudge, but the more complaining they do, the closer I feel we are getting to actual answers.

Often folks attacks the Path and use it to try and attack the overall Theory and the Fact of Evolution.  The Discovery Institute is frequently guilty of this, it's one of the tactics they use to make people mistrust science.  The problem is even if a biologist doesn't have to precise path from dinosaurs to modern birds, the relationship is well supported and also supports the theory and fact of evolution.  Work will continue, which is something the DI can't seem to say about their religious ideas, can they?  Have they managed to produce anything that takes their idea beyond pseudo scientific wishful thinking?  Not yet!  Claiming to be science doesn't make your ideas automatically scientific!  If that were the case then we would also be teaching Astrology alongside Astronomy and Numerology with Mathematics.  What a frightening thought!

The Path, the Fact, and the Theory are three different contexts in which we use the term 'evolution'.  They are related, but not interchangeable.  The Theory, even changes to the Theory, doesn't change the Fact.  The fact [pun intended] that we don't know a specific Path of a change, doesn't mean Theory should be discarded, or make the Fact irrelevant.  Be clear in your context and it certainly makes things a whole lot clearer as you think about and discuss Evolution.

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