Wednesday, August 24, 2005

[geek] "Testing Darwin"

In light of the recent controversy over the non-controversy that is evolution, I found the above-linked article quite interesting - digital life, a software package named 'Avida', evolving in ways that Creationists and Intelligent Design advocates say can't happen:
The researchers set up an experiment to document how one particularly complex operation evolved. The operation, known as equals, consists of comparing pairs of binary numbers, bit by bit, and recording whether each pair of digits is the same. It's a standard operation found in software, but it's not a simple one. The shortest equals program Ofria could write is 19 lines long. The chances that random mutations alone could produce it are about one in a thousand trillion trillion. To test Darwin's idea that complex systems evolve from simpler precursors, the Avida team set up rewards for simpler operations and bigger rewards for more complex ones. The researchers set up an experiment in which organisms replicate for 16,000 generations. They then repeated the experiment 50 times. Avida beat the odds. In 23 of the 50 trials, evolution produced organisms that could carry out the equals operation. And when the researchers took away rewards for simpler operations, the organisms never evolved an equals program. “When we looked at the 23 tests, they were all done in completely different ways,” adds Ofria. He was reminded of how Darwin pointed out that many evolutionary paths can produce the same complex organ. A fly and an octopus can both produce an image with their eyes, but their eyes are dramatically different from ours. “Darwin was right on that-there are many different ways of evolving the same function,” says Ofria.
Funny - you can create an irreducibly complex structure randomly: by rewarding greater levels of complexity. If this added complexity confers some advantage to the organism, it will be rewarded. You don't need a designer to get an eye. Remember this the next time you hear someone say that evolution can't be tested in the lab... [stumbled on this indirectly from MSNBC's "Cosmic Log" column]


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