Tuesday, June 24, 2008

Teaching the "weaknesses" in evolutionary theory

Oh, let's do!

I looked at the website where the Texans for Better Science Education lay out examples of the "weaknesses" that should be taught. They're pretty weak, all right. I think that most of these could be included in a science course as "common myths about evolutionary theory."

Consider these:

The Cambrian explosion quickly produced all of the basically different body structures, and some of these have since become extinct. This is very different from the evolutionary tree of life, which suggests a slow and gradual increase in body structures.

No, no it doesn't. Evolutionary theory provides no reason to think that body structures should change at a slow constant rate. The synthetic theory emphasizes why bursts of adaptive change should happen episodically.

Many life forms persist through large expanses of geologic time with essentially no change. Evolution theory suggests that mutations occur randomly over time and are selected to produce continuing change as the environment continually changes.

No, no it doesn't. Some organisms may well have relatively constant environments for millions of years.

Selective breeding has produced only very limited change with no new structures occurring over thousands of years and multitudes of generations of selection.

Umm... teosinte? I think that biology texts should devote a lot more attention to selective breeding, as the best concrete examples of evolution in action.

So, that reflects on the basic problem with the idea of teaching evolution's "weaknesses": A real weakness is not a matter of ignorance, but a matter of evidence weighing in favor of some alternative hypothesis. We don't have that here.

No comments: