This new video from the Discovery Institute is a clear and concise explanation of why we should doubt the power of random mutations and natural selection to build new, functional information content in DNA. Here are some excerpts, but watch the whole video (below) to see the helpful way they illustrate the truth of this:
According to modern evolutionary theory, new proteins and new forms of animal life arise through random genetic mutations, sifted by natural selection. But in an alphabetic text or a section of computer code, random changes typically degrade meaning, or functionality, and ultimately generate gibberish.
STEPHEN MEYER: “As we've come to appreciate the digital or typographic character of genetic information…it raises some really interesting questions about the efficacy of that mutation-driven mechanism…. If you start making random changes to a section of computer code, you're much more likely to degrade the information that's there already than you are to come up with a new operating system or program.” …
Scientists in the 1960s didn't know how many of [the possible arrangements of amino acids] were actually functional…. That didn't stop evolutionary biologists from speculating. Many argued that there must be a high proportion of functional sequences among all possible sequences so that a random search for a new functional sequence would have a high probability of success.
STEPHEN MEYER: “The way they did that is to say, well maybe biological sequences are…not nearly as picky about which characters are where as written language is or as computer code is…. Maybe proteins don't really care which amino acid is where and there’s a great deal of variability, and therefore you can have the same function performed by a huge number of protein chains and a huge number of genes.”
But recent experiments in molecular biology and protein science have replaced speculation with data. These experiments have established that DNA-based sequences capable of making functional proteins are, in fact, extremely rare among the vast number of possible sequences….
For even a single functioning protein fold to arise, the mutation selection mechanism would have time to search just a tiny fraction of the total number of relevant sequences—one ten-trillion-trillion-trillionth of the total possibilities. It follows that it is overwhelmingly likely that a random mutational search would have failed to produce even one new functional protein fold in the entire history of life on Earth.