Wednesday, March 25, 2009

Stasis Is Data, says Don McLeroy

 
Don McLeroy is a creationist dentist from Texas. His claim to fame is that he is the current chair of Texas State Board of Education. That board is trying to insert creationist-friendly standards into the state curriculum.

Today, the Austin American Statesman published an op-ed piece by McLeroy in which he defends creationism: Enlisting in the culture war.

It makes for amusing reading. I want to address one particular issue that illustrates how creationists misunderstand the science they criticize. It vividly points out what we are up against. The opponents of science don't even take the time to understand what they oppose.

Let's start by looking at the chart (right). It illustrates the now-famous pattern of punctuated equilibria as detected in the fossil record. What it shows is that speciation by cladogenesis (splitting) is associated with morphological change. When a new species evolves from a parent species it does so quite rapidly. After the speciation event (horizontal lines on the chart) the two species exist side-by-side in the same environment for millions of years without significant morphological change. Eventually they becomes extinct as shown by the termination of the vertical lines.

Species exist for 5-10 million years. During most of that time they do not change very much. This is what Eldredge and Gould called "stasis." The entire pattern is one of stasis interrupted by short periods of evolution at the time of speciation, or "punctuated equilibria."

The patterns in the fossil record raise interesting questions. One of the most important is whether it represents the normal pattern of evolution or whether it is confined to a minority of clades. What causes stasis? Why is change associated with cladogenesis? Why do species go extinct? All of these are widely discussed in the scientific literature.

None of the questions is a challenge to evolution. Punctuated equilibria is a pattern that might lead to an extension of evolutionary theory.

Now let's look at what McLeroy writes in his op-ed piece.
It is absolutely safe to say that if you meet somebody who claims not to believe in evolution, that person is ignorant, stupid or insane (or wicked, but I’d rather not consider that).

Richard Dawkins
The next step in resolving this controversy is simply to use the scientific method to weigh in on the issue of evolution. Consider the fossil record. What do we actually observe? What are the data?

Stephen Jay Gould stated: "The great majority of species do not show any appreciable evolutionary change at all. [This is called 'stasis.'] These species appear ... without obvious ancestors in the underlying beds, are stable once established and disappear higher up without leaving any descendants."

"...but stasis is data..."

Once we have our observations, we can make a hypothesis. The controversial evolution hypothesis is that all life is descended from a common ancestor by unguided natural processes. How well does this hypothesis explain the data? A new curriculum standard asks Texas students to look into this question. It states: "The student is expected to analyze and evaluate the sufficiency or insufficiency of common ancestry to explain the sudden appearance, stasis, and sequential nature of groups in the fossil record." It should not raise any objections from those who say evolution has no weaknesses; they claim it is unquestionably true.
I don't see a problem with explaining punctuated equilibria to high school students, assuming, of course, that Texas has competent science teachers. It would teach students about critical thinking and reinforce some of the fundamental concepts of evolution.

This isn't what McLeroy has in mind. I think it's very clear what he thinks about punctuated equilibria. He thinks it supports some (unstated) version of creationism. The point of his op-ed piece is to convince his supporters that scientists are trying to hide important evidence for creationism.

I'm assuming that McLeroy simply doesn't understand the science behind punctuated equlibria, or evolution, and that's why he misrepresents it in his article. This means that McLeroy is ignorant, stupid, or insane. There's another possibility but we won't consider that.

Here's something I found on the Wikipedia website for Don McLeroy.
In 2009, McLeroy spoke at a board meeting with several quotes from scientists in an attempt to discredit evolution. The quotes were later revealed by a biology teacher to be incomplete, out of context, or incorrect taken from a creationist website.[10][11] McLeroy said that while "some of the material was taken from the creationist site, he added: “A lot of the quotes I did get on my own.”
You may be wondering if these out-of-context quotations include anything on punctuated equilibria or stasis. It would be embarrassing to find out that McLeroy repeated those misleading quotations only a few weeks after learning that they were wrong. Here's the list: Collapse of a Texas Quote Mine.

Pray for Texas. The decision on education standards will be made any day now.


[Image Credit: Punctuated Equilibrium and Patterns from the Fossil Record]

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