Joined: Oct. 2006
Creationists, especially the intellegent design crew, hinge much of their anti-evolution rhetoric on the idea of complexity--e.g., organisms are "too complex" to have evolved therefore God or some unnamed intelligent designer put them there. Now the colloquial meaning of the term "complexity" refers only to the ability of Homo Sapiens to understand things. Easily comprehensible things are "simple" while difficult to comprehend things are "complicated." This concept can not be divorced from subjective human understanding. Complexity, defined colloquially, is not a physical quantity and has absolutely nothing to do with phenomena themselves but only how human perceive it. Hence, such an idea is all but meaningless in a scientific context; for how can a concept rooted in human psychology mean anything when applied to phenomena independent of that psychology? Does anybody disagree with me so far?
Now, from this list of scientific definitions of the term we see complexity defined exclusively in terms of quantities related to the order of algorithms. These are still not physical quantities. We can compute the complexity of an algorithm used to manufacture a watch, but we can't say a watch itself has this complexity, or any complexity at all--as opposed to mass, volume or temperature. There is no way algorithmic complexity can be attributed to physical phenomena. Again, does anybody disagree with me?
Now, where I'm confused is how the term is used specifically in biology. Biologists do discuss a distinction between "simple" and "complex" organisms. A bacterium is simple because it has only one cell without a nucleus while a human is complex because she has trillions of diverse cells all with nuclei. However, this seems no different from the colloquial idea discussed above. Is an H. Sapien more complex than an E. Coli merely because the former has more parts to be understood by other H. Sapiens, or does biological complexity have a more rigorous definition?