Real Controversies in Evolutionary Biology
John Timmer of Ars Technica has written a very good article in his journal regarding what he learned are the real controversies in evolutionary biology. Any evolutionary biologist will tell you that there are real controversies; they're the driving force behind scientific progress. They are not weaknesses or holes, they're simply things that scientists are still working out. As our knowledge of the simplest things grows, we move on to tackling the more difficult questions. Some are difficult because it's hard to find data and some are difficult because of technical considerations. This, too, is how science works.
What Timmer does in his article, though, is to make crystal clear the differences between the manufactured controversy of the Discovery Institute and its lackies and the real controversies in real science. It's well worth a read, and here are a few excerpts:
Evolution: what's the real controversy?Well, that came out a bit longer than I'd intended. Nonetheless, Timmer's outstanding comparison of the controversies that are and those that Neocreationists simply wish there were is an excellent piece, particularly if you aren't someone who spends much time following the nuts-and-bolts of recent research in the various disciplines that add up to evolutionary biology. Have a good read.
The scientific study of evolution is filled with controversies. That was one of the messages coming out of a two-day symposium on the latest in research from the field that was hosted by Rockefeller University last week. I'll discuss the scientific details of some of the talks separately, but it's worth analyzing these controversies in light of the "academic freedom" bills that are being considered by a number of states, which purport to protect teachers who discuss controversies regarding evolution.
Nationwide, nearly half a dozen states are considering variants of such bills, some of which throw in the origin of life and climate change for good measure... These bills appear to have originated at the pro-Intelligent Design thinktank the Discovery Institute, and constitute part of its latest effort towards reducing the teaching of evolution in public schools...
So, might Discovery actually be on to something here? It's worth doing a comparison of the controversies they'd like to see taught with the topics that are considered controversial within the actual scientific community... Those ostensible controversies fall into three major groups: existence of common descent, power of natural selection, and the existence of proteinaceous machines...
...In the real world of science, common descent of animals is completely noncontroversial; any controversy resides in the microbial world...
Russ Doolittle presented an analysis based on individual folds in proteins that clearly resolved the Bacteria, Archaea, and Eukaryotes, while a distant relative, Ford Doolittle, argued that the prevalence of horizontal gene transfer at the bacterial level made any such trees questionable, or at best uninformative. Meanwhile, Thomas Cavalier-Smith argued forcefully that gene-based trees miss out on significant evolutionary events, such as the transition that gave the Archaea a radically different membrane chemistry...
Selective pressure made appearances in nearly every session. Selection for self-replicating RNAs and for enclosing biochemical precursors within membranes were central to the origin of life work of Gerald Joyce and Jack Szostack, respectively. At the other end of the spectrum, the researchers exploring human evolution (Katherin Pollard, Bruce Lahn, and Svante Pääbo) spoke of the challenges of identifying signs of selection amidst the genetic drift that's occurred within the genomes of mammals in general and primates in particular.
Here, it was clear that there simply is no controversy. In contrast to the arguments over bacterial trees and the origin of eukaryotes, none of the researchers felt compelled to explain or justify their focus on the role of mutation and selective pressure. Concerns, when they arose, were simply focused on identifying the consequences of selection. As such, Discovery's focus on presenting a controversy here seems hallucinatory...
Michael Behe, a Discovery fellow, has advanced the argument that some aspects of cellular life are analogous to machinery, and thus must have required the same attentive design that a machine does... But items Behe might consider molecular machines did appear in the talks, and their role was informative.
The proteasome is one complex of dozens of proteins that was mentioned in a couple of talks. Despite the enormous complexity and large number of specialized proteins in a proteasome, evolution readily explains its origins through gene duplication and specialization. Simplified forms, with fewer proteins, exist in Archaea and Bacteria. Not only are these simple versions of the proteasome an indication of its evolution, the gradual increase in its complexity allowed researchers to use it to infer evolutionary relationships among the three branches of life...
Evolution clearly has no shortage of controversies. But none of those controversies involve the basic principles of evolution, and all of them operate within a framework where random mutation and selection play a key role in creating diverse species that are related by common descent. It's clear that the Discovery Institute is trying to introduce controversies that don't exist, while ignoring those that do. That's why the academic freedom bills it's promoting are such dangerous things; while supposedly promoting intellectual analysis, they're actually an attempt to pave the way for misinformation to enter the scientific classroom...
