Turned up to eleven: Fair and Balanced

Thursday, February 07, 2002

Just a quick post about evolution, I think that there is a level of opportunity given to those who don't accept evolution that is simply undeserved. The evidence for evolution is absolutely, stunningly, overwhelmingly huge. Simply put, every scrap of observed evidence supports the theory that all life evolved from a single progenitor cell. The fossil record is often percieved as sparse, and this is considered evidence against evolution. But there is a massive amount of evidence besides the fossil record, such as DNA and RNA sequence evidence, that argues for the currently held view. A quick primer on this subject. Among the many parts of a cell, one of the ones that is absolutely necessary is something called a ribosome. A ribosome is made up of proteins and RNA, and its purpose is to "translate" RNA messages produced from genes into proteins. This activity, sometimes written DNA>RNA>Protein, is sometimes referred to as the "Central Dogma" of Molecular Biology. Because ribosomes are so vital to the viability of a cell, they have existed for a very long time, and are considered likely to be a constituent of the very early cells. The ribosomal RNA, in particular, is very well "conserved", which means that everyone has it, and it is similar in every living thing. Interestingly, it has regions that are almost identical in everyone, and other regions that are not so similar, that do not play as direct a role in its function. This molecule has been used as a "molecular clock", in which differences from one species to another can serve as a way to measure the relatedness of various organisms. Other methods, such as DNA-DNA hybridization, and comparisons of other genes by sequence, have added to the phylogenetic "tree of life". This is really interesting biology, and in many ways the overall structure of the tree (its really more of a bush, branching out in all directions), is only explained by the evolutionary "single origin" theory. Now, no one can ever "prove" that evolution happened, i.e., prove that it is the only explanation, as long as supernatural explanations (God did it) are allowed. The argument, therefore, is largely irrelevant to the science at hand. Those who truly want to understand evolution, however, should study the work of Carl Woese (a founding father of phylogenetics), or the popularizations by Stephen Jay Gould and Richard Dawkins. Many will want to read the work of Michael Behe as well, but I really recommend reading that with a skeptical eye. He basically argues a dressed up "God of the Gaps" tack. He says that there are enzymatic pathways which cannot be altered, and therefore God must have designed them. This argument is in fact very old (ever seen half an eye?), and has been discredited by scientific advancement at every turn. That's two long boring posts today. No more geeky science stuff, I promise (for a while!)