Introduction

4. What are the Main Arguments for Evolution?

It would be exceedingly difficult to summarize all of the arguments for evolution in a concise fashion here. However, the most important point to remember is that evolution theory, like all scientific theories, was originally a solution to a problem. What's remarkable about anti-evolution propaganda is that it never acknowledges this fact, and so never takes on the burden of producing a better explanation for that original problem.

So what was this original problem that evolution theory was invented to solve? It's called the Linnaean Taxonomy, named after Carl Linnaeus (1707-1778). If you are not familiar with the term, it is the categorizations of plant and animal species into a hierarchical structure. This structure has 7 layers: Kingdom, Phylum, Class, Order, Family, Genus, and Species. Now, the remarkable thing about this system is that the early naturalists classified animals into a hierarchical "family tree" structure long before the theory of evolution was proposed. In other words, all naturalists agreed long before Darwin that the animal kingdom appeared to be a family tree.

Now the question becomes: why did they do that? The theory of evolution did not exist yet, so they obviously didn't do it to please "evolutionists", as creationists are wont to call them. What was their reasoning? Well here's where we run into an interesting coincidence in the animal kingdom: the appearance and development of animal features also looks like a family tree. In other words, you can take any given feature and trace its appearance, in various levels of complexity, along lines of animal species. Sometimes a feature will change in one direction for one branch of the tree and another direction for the other branch of the tree, and as you examine more complex organisms on any given branch, the two diverging features always (I must repeat this: ALWAYS) stay that way. They never jump back and forth; while features can jump between bacteria due to genetic material exchange (they're so small that they can literally swap pieces of DNA), we have never observed a feature exchange between complex organisms. There is no reason why an engineer would steadfastly refuse to take features from one product line and use them in another, so why would this be the case for an engineered biosystem?

This is a classic example of a problem in need of a solution. It is not enough to classify it as coincidence, not when it is so incredibly consistent. And the problem gets worse: when those early naturalists examined the geographical distribution of the animal kingdom's "family tree", they discovered yet another impossibly unlikely "coincidence": species which appeared to be very close to one another on the family tree were also geographically close to one another. And whenever someone found what appeared to be an exception to this rule, they discovered a migratory path. Centuries later, the rule is unchanged: when species show a biological connection, they also show a geographical connection.

The significance of these two intertwined globe-spanning coincidences cannot be overstated: it was an enormous problem for taxonomy. If someone had indeed designed and created these species, he went to enormous lengths to make them appear to be related, by carefully arranging their structures and geography to match! Why would he do this? There was no intrinsic need for this, as we have proven in the last century by artificially moving species outside their natural habitat and seeing that in many cases, they thrive in far-off environments. There was no intrinsic need for features to be arranged in a hierarchical fashion, or for structural proximity to invariably mirror geographical proximity. So why would the designer do this? No one ever provided an answer ... until Darwin.

This, then, is the single largest argument for evolution: it is a solution to a problem that no other theory can explain. Creationists often try to argue that God could have chosen to make the animal kingdom look that way, but they can't explain why or how. And if they can't explain why or how, then they actually do not have an explanation. Can anyone explain how you would derive the prediction of a "family tree" animal kingdom from the idea of God? It's not enough to say that God reused previous designs; that would explain the similarities but not the divisions in the family tree. The Linnaean taxonomy is a family tree, not a family sponge. Only evolution offers a real explanation: the kind of explanation where you can start from its mechanism and use it to logically work forward to predict the outcome.


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