Monday, April 23, 2007

The theory of evolution

Today I showed a colleague my blog, and he noticed my post on "Darwin-related activities". He asked me if I believe in Darwin's theory of evolution. To say I was surprised by this question would be an understatement. The way he phrased it and the tone in his voice, made me turn around to look at him. With his interests in phylogenetics and systematics, surely he stares evolution in the face every day!

The closer look at his face confirmed my suspicion. Uh oh. My colleague is not convinced evolution is real.

We could not talk for very long, I still had stuff to finish up in the lab and I had to leave to pick up the kids 20 minutes later, but we talked briefly.

I explained that in my opinion "believe" is the wrong word to use with regard to a scientific term like "evolution." I accept evolution as the best explanation of both the diversification of and similarities between species, until a better theory comes along.

Scientists come up with theories. Based on those theories they formulate hypotheses that can be tested by doing experiments. They do the experiments, collect data, analyze the results, which either support their hypothesis or don't. If they don't, they formulate another hypothesis and the cycle starts all over. The accumulation of experimental data and results as published in reputable, peer-reviewed journals forms the basis of how widely accepted a theory becomes.

The theory of evolution has withstood thousands, and thousands of papers published over many years, all of which have ultimately supported the theory. Or more accurately, to the best of my knowledge, no publication exists with evidence that is incompatible with the theory of evolution*. That would have forced scientists back to the drawing table. If there was evidence that clearly disputed the theory of evolution, there would be an army of scientists on it right now.

After talking with my colleague for a few more minutes it became clear that he is aware of different proposed mechanisms for evolution. Scientists agree that evolution is a result of accumulation of mutations, with different ideas about the nitty gritty details of the mechanisms of speciation. How fast, what causes different rates of evolution. It is possible that his indecision lies there, with the mechanisms of evolution, instead of evolution itself.

Well, I suppose we'll continue the discussion, hopefully tomorrow. I'm curious to find out more about his opinion.

*Note: Bible quotes do not constitute evidence.

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