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New Analyses Bolster Central Tenets of Evolution Theory

"Evolution is a way of understanding the world that continues to hold up day after day to scientific tests," Lander said.

By contrast, said Alan Leshner, chief executive of the American Association for the Advancement of Science, Intelligent Design offers nothing in the way of testable predictions.

"Just because they call it a theory doesn't make it a scientific theory," Leshner said. "The concept of an intelligent designer is not a scientifically testable assertion."

Asked to provide examples of non-obvious, testable predictions made by the theory of Intelligent Design, John West, an associate director of the Discovery Institute, a Seattle-based ID think tank, offered one: In 1998, he said, an ID theorist, reckoning that an intelligent designer would not fill animals' genomes with DNA that had no use, predicted that much of the "junk" DNA in animals' genomes -- long seen as the detritus of evolutionary processes -- will someday be found to have a function.

(In fact, some "junk" DNA has indeed been found to be functional in recent years, though more than 90 percent of human DNA still appears to be the flotsam of biological history.) In any case, West said, it is up to Darwinists to prove ID wrong.

"Chance and necessity don't seem to be good candidates for explaining the appearance of higher-order complexity, so the best explanation is an intelligent cause," West said.

Simple and Hard

The controversy that has periodically erupted around evolution can be attributed at least in part to the fact that it is both simple to understand and hard to believe.

Charles Darwin and Alfred Russel Wallace, working independently in the early- to mid-1800s, each came up with the concept of "natural selection." Each sought to explain the astounding diversity of life he found in exotic places, Darwin in the Galapagos Islands and Wallace in Brazil.

Their idea was this:

By some accident of nature whose workings neither man could explain, an organism may exhibit a variation in shape, color or body function new to the species. Although most of these new traits are damaging -- probably lethal -- a small fraction actually help. They may make it easier to hide from predators (like a moth's coloration), exploit a food source (an anteater's long tongue), or make seeds more durable (the coconut's buoyant husk).

If the trait does help an organism survive, that individual will be more likely to reproduce. Its offspring will then inherit the change. They, in turn, will have an advantage over organisms that are identical except for that one beneficial change. Over time, the descendants that inherited what might be termed the "happy accident" will outnumber the descendants of its less fit, but initially far more numerous, brethren.

There are two important consequences of this mechanism.


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