Friday, September 4, 2009

Evolution's Big Mystery: In the Beginning (part 2)

Where did evolution start? Where did that first tiny self-replicating particle come from? This is the biggest remaining question of evolution, the one creationists still like to claim is the fatal flaw of Darwin's theory. (This is part 2 of a three-part blog; you can read part 1 here.)

What do we actually know about the very beginnings of life?

Creationists start this question from a false premise. It's an exact analogy with their classic, "You can't prove God doesn't exist!" That is, they start by asserting that some magical fact is true, and then challenge you to prove them wrong. Since there can't be any evidence one way or the other (it's magic, after all), they cry, "Aha! See, I'm right!"

With the origins-of-life question, creationists' position amounts to the same assertion: They claim that God created life, and then challenge science to prove them wrong. But that's backwards. Anyone who claims they know how life started, including creationists, shares the same burden of proof!

I thought this blog was going to require a huge amount of research, but thanks to the power of collaborative editing, also known as Wikipedia, I discovered not only was all the information readily available, but the breadth and depth of the research into the origins of life is breathtaking. Here is the main article:
http://en.wikipedia.org/wiki/Abiogenesis
I was struck by the variety of proposals. Everything from the classic "primordial soup" proposed clear back in 1924, to this sample of modern theories:
  • Deep sea vents. These volcanic vents spew nutrient-rich superheated water full of reactive chemicals. "Extremophiles" live there, bacteria and such that thrive in 300-degree water!
  • Deep underground. Scientists were amazed to discover bacteria living two miles underground in microscopic fissures in the rocks. Heat, minerals, and organic matter are abundant, and scientists have proposed chemistry that could have created life.
  • The radioactive-beach theory. Billions of years ago the moon was much closer and tides were much stronger than today. Uranium particles and other radioactive material, more prevalent back then, could have been concentrated at the high-water mark, leading to enough radioactivity to trigger chemical reactions that don't occur under normal conditions.
These, and many other fascinating theories are covered in depth in the Wikipedia article.

What's amazing to me is not how little we know, but how much we know. Investigating an event that happened 3.8 billion years ago is an very hard task, and even if we find plausible answers, we can never be sure we're right since we weren't actually there to watch it happen. But there is a lot of really good science that has been done, and some very exciting answers that are emerging.

Getting back to our friendly creationists: If we're comparing apples to apples, what sort of evidence have they provided for their magical (i.e. God) theory of the origins of life? Have they done experiments? Found evidence? Presented peer-reviewed publications subject to scrutiny and debate?

Of course not. All they've done is to assert, with no justification, that their magical explanation of how life started is the prove-me-wrong default answer. They're trying to claim that, because their answer was around long before science, that it's the "king of the hill" that we have to knock down.

Scientists dismissed that specious argument long ago, but unfortunately it still permeates the debate.


2 comments:

Dear readers -- I am no longer blogging and after leaving these blogs open for two years have finally stopped accepting comments due to spammers. Thanks for your interest. If you'd like to write to me, click on the "Contact" link at the top. Thanks! -- CJ.

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