Simply reading through news articles, watching online videos and generally surfing the web, you can come across many sites, articles, videos et cetera which attack evolutionary theory. Many claims are made about the validity of the theory and then parts or the entire theory is supposedly refuted in one fail swoop. The arguments presented may even sound “logical” or correct to the average reader. Of course, why would we see a chimp give birth to a human? That’s simply ridiculous!

It is ridiculous dear reader, it truly is. The twist is that evolution does not propose such a thing. In such an instance you have been fed a strawman argument which we went over in the introduction. Some do this knowingly but many do it unwittingly – they don’t realize that they’ve presented a distorted version of evolution. This can usually be explained by simply not understanding what evolution is.

So what is evolution? Excellent question, let’s find out!

Audesirk, Audesirk, and Byers (2002) define evolution as, "the descent of modern organisms with modification from preexisting life-forms; strictly speaking, any change in the proportions of different genotypes in a population from one generation to the next." (G-9).

Alters (2000) defines evolution as, "a scientific theory of organismal change over time originally developed by Charles Darwin; it embodies the ideas that species alive today are descendants of species living long ago, and that species have changed and diverged from one another over billions of years; the process of change over time by which existing populations of organisms develop from ancestral form through modification of their characteristics." (G-10).

These definitions may be in contrast to the idea that many hold of evolution. It is often thought to be a progression of some sort toward a particular goal (usually thought to be us Homo sapiens sapiens). This concept is incorrect and a fairly old one. It is akin to the antiquated idea of a hierarchy of organisms – much like Aristotle's great chain of being or scala naturae. These ideas about life are wrong yet they persist. While it served as his attempt at organizing life into groups and is one of the first attempts at taxonomy, it is nonetheless, wrong. Evolution has no predestined goal, no achievement to shoot for. It is a continual, unyielding process with no predetermined goal. Professor Paul Olsen (2004) points to some underlying motivations for this ladder concept stating it, "Supported feudal social stratification as well as putting everything in its place - we still have strong vestiges of that concept."

At the very bottom of this chain we find minerals such as soil, rocks, sand, metals and so forth. At the top we will find God, the “creator”, the prime mover and et cetera. Below him are the angels and demons and smack in the middle of the chain are humans. We are placed above other animals but below angels and demons. This idea was so powerful that it persisted for centuries – even residing still in the 21st century.

The Problem of Equivocation

Another problem in understanding what evolution is – equivocation. Equivocation occurs when someone utilizes a word which has several meanings within two different contexts. A formal explanation is given by Kahane and Tidman (1995):

“A term or expression is used ambiguously or equivocally in an argument when it is used in one sense in one place and in another sense in another. When we fail to notice a shift in meaning of this kind and are led to accept a conclusion that we otherwise would have denied, then we are victims of the fallacy of equivocation (p. 311).”

We can often see this fallacy at work in arguments against evolution. It may be the product of ignorance or it may be intentional, nevertheless, the fallacy is committed. Let me give you an example. When debating evolution, I often have people point to “cosmic evolution” or “chemical evolution” and ask how Darwin’s theory explains aspects of them. My usual reply of “it doesn’t” is met with confusion and usually a proclamation of victory. However, they aren’t talking about Darwin’s theory. A common colloquial usage for “evolution” can be found in the dictionary and defined as:

“A gradual process in which something changes into a different and usually more complex or better form” (Pickett, 2001).

This is a different definition than the ones we have seen previously. What we have is the term evolution with two different definitions which are determined by the context in which you use the word. When someone speaks of cosmic evolution, they are speaking about the gradual process of change the universe has gone through up to present time. No where in Darwin’s “On the Origin of Species” will you find him explaining the life cycle of a star or the formation of galaxies nor will you find this in any evolutionary biology book.

The definitions we first encountered in this article refer to the specific scientific theory of biology. It concerns populations of living organisms, not galaxies or solar systems. Equivocation can be a subtle fallacy which is why asking someone to define the terms they use.

Another often equivocated term is “theory”. We hear people say over and over again, “evolution is just a theory” or “you can’t say it’s fact since it’s only a theory” and on and on and on. The term “theory” also has different contextually dependent definitions. In one sense it can mean:

“An assumption, conjecture” (Pickett, 2001)

We hear this sense of the word utilized, for instance, when someone might say, “I have a theory about that…”. What they are saying is that they have an idea, a conjecture they have thought of regarding a particular subject. This usage of the term differs significantly when someone refers to a theory in a scientific context. A scientific theory is defined as:

“A set of statements or principles devised to explain a group of facts or phenomena, esp; one that has been repeatedly test or is widely accepted” (Pickett, 2001).

A scientific theory is much more than a mere conjecture, much more than a simple guess. Those who hurl the “it’s only a theory” argument can be shown the error of this argument by letting them know that there are many theories such as the germ theory of disease, the theory of gravity, cell theory of biology et al. These are more than just guesses that scientists have conjured up. For those who intentionally utilize this fallacious argument, their hope is to cast doubt upon the veracity evolution. They hope to tear it down by proposing to expose critical flaws in the framework of the theory – many attempts of which utilize the strawman fallacy. This was recognized by Isaac Asimov when he stated:

“Creationists make it sound as though a 'theory' is something you dreamt up after being drunk all night.”

So, we now have a solid definition of evolution and know what it means to be a scientific theory. Simply knowing these two things has put you, my readers, ahead of much of the populace in respect to this topic. We’re not done yet though, oh not by a long shot my friends. We still have to get to know the basics of evolution and the mechanisms involved therein. Look for Part II where we will begin to explore the mechanism of natural selection.

References
(In order of appearance)

Audesirk, T., Audesirk, G., & Byers, B. (2002). Biology: Life on earth. (6th ed.). Upper Saddle River: Prentice Hall.

Alters, S. (2000). Biology: Understanding life. (3rd ed.). Sudbury: Jones and Bartlett Publishers.

Olsen, S. (2004). Evolution in Hawaii. Washington, D.C.: The National Academies Press.

Pickett, J. (Ed.) (2001). The American Heritage Dictionary. New York: Dell Publishing.

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