June 6, 2004 - June 12, 2004 Archives
Columnist Linda Seebach of the Rocky Mountain News has written a column on Project Steve, the NCSE’s parody of creationist lists of evolution-doubting scientists. These lists, touted most prominently by the Discovery Institute, consist of scientists (and random other people) that are creationists, that doubt evolution in some way, or that are willing to put their name on a certain-to-be-abused vague statement encouraging “careful examination of the evidence”.
The first Icon I will explore is the Icon of the Explanatory Filter being reliable, or in the words of Dembski “No false positives”.
Dembski’s opinion on “false positives” seems to have evolved over time. From an initial claim of reliability and “no false positives” via an admission that if the filter erroneously attributes design, it is useless to acceptance of “false positives”, the “Explanatory Filter” evolved from reliable to useless.
Despite the fact that “false positives” are inevitable and thus the filter is not only unreliable but in fact useless, Dembski and the ID movement seems to continue to insist that the Explanatory Filter is a reliable theoretical foundation for detecting design.
Intelligent Design creationists are extremely fond of diagrams like those on the right. Textbook illustrators like them because they simplify and make the general organization of the components clear—reducing proteins to smooth ovoids removes distractions from the main points—but creationists like them for the wrong reasons. "Look at that—it's engineered! It's as if God uses a CAD program to design complex biological systems!" They like the implication that everything is done with laser-guided precision, and most importantly, that every piece was designed with intent, to fill a specific role in an apparatus that looks like it came out of a high-tech machine shop at a Boeing aerospace lab.
This is, of course, misleading. Real organelles in biology don't look glossy and slick and mechanical; they look, well, organic, with fuzziness and variability and, most importantly, mistakes and slop. What these biological machines look like is not the precisely engineered output of a modern machine shop, but like bricolage. Bricolage is a term François Jacob used to contrast real biology with the false impression of nature as an engineer. It's an art term, referring to constructions made with whatever is at hand, a pastiche of whatever is just good enough or close enough to the desired result to make do. It covers everything from the sculptures of Alexander Calder to those ticky-tacky souvenirs made from odd bits of driftwood and shells glued together that you can find at seashore gift shops.
The closer we look at the developmental biology of organisms, the more apparent the impromptu, make-do nature of their construction is. This is not to imply that they don't work well or efficiently, but only that the signature of intent is missing. What we see is function cobbled together out of scrap from the junkyard. One clear example of this property is a gene, nanos, in Drosophila.
Continue reading "Bicoid, nanos, and bricolage" (on Pharyngula)
(Note: Pharyngula will be inaccessible for much of the day on Sunday, 13 June, while maintenance work is done on the electrical system out here in Morris, Minnesota. Look for it to be back online in the early evening.)
As I explained before, entropy may appear to be a simple concept but is easily confused. A good example is the claim made by Jerry Bauer who claims to be using Feynman’s equation to calculate the entropy of mutations.
Let’s see what Jerry claims and then compare this to what he should have said. I pointed out to Jerry that Feynman presented a hint to Jerry as to how to calculate entropy correctly:
I've written before about Casey Luskin and his IDEA club, which exists to promote Intelligent Design on college campuses. I've criticized it for having purely religious motivations (which Luskin tries desperately to conceal), and for their very poor understanding of the science they claim to criticize. Jack Krebs and Wesley Elsberry here at the Panda's Thumb have also ripped into Luskin over both of these issues.
Luskin, as you might guess, is indignant. In particular, he is irate that he was caught with a current listing at a conference that describes the IDEA club as a "ministry". It wasn't his fault, he protests. At length. At extravagant length.
But a look at the history of the IDEA club reveals a different story.
Continue reading "Casey Luskin and the evolution of an IDEA" (at Pharyngula)
One of the characteristics of science is that it is self correcting. One of the most common and successful methods for self correction involves peer review. In case the reviewers do not catch the errors, comments from colleagues can result in a later correction of the mistake. Examples of such can be found throughout the scientific world. Relevant to evolution the following examples come to mind: Piltdown Man, Haeckel embryos, Nebraska man. (See Is Evolution Science?. Scientific theory is always tentative, open to refutation, reaffirmation, and alteration when more and more data become available.
Despite this we see ID proponents such as Nancy Pearcey speaking out against what they consider to be “defenders of falsehoods” when accusing Darwinists of refusing to correct errors in textbooks. Most of their perceived ‘errors’ are in fact overblown. What is relevant however is that ID proponents seem to expect Darwinists to be ‘self correcting’.
Paul Nesselroade similarly observes that when it comes to public trust, science should be self-correcting .
The public trust afforded to science comes, in part, from its own claim that it is self-correcting, constantly engaged with the evidence and paying tribute to no person, philosophy, or creed. But how can this basis for trust be reconciled with a refusal to hear challenges or examine its own presuppositions?
Then there is David Buckna who argues without much supporting evidence that:
Good science is always tentative and self-correcting, but this never really happens in the case of evolution.
Often the ID proponents seem to confuse legitimate debate about issues as a weakness of evolutionary theory.
Another major misconception is that science is simply the accumulation of observational fact, and theories are merely unsubstantiated guesses. This “facts only” view of science misses the core of what the scientific enterprise really is. In my opinion, nothing could be more deadly to teaching science than to divorce it from the unifying theories which give observations meaning. They make the world comprehensible. They also generate the testable hypotheses (expectations) that drive further exploration and discovery. When science is taught as only factual observation (something the standards passed by the Board would encourage), then disagreements among scientists and changing scientific views are seen as weaknesses and failings of scientific knowledge. However, the exact opposite is the case. It is the dynamic, changing, self-correcting nature of science that is its very strength. The less science is seen as a body of established knowledge, the more inherently interesting and exciting it becomes.
Keith B. Miller in The Controversy over the Kansas Science Standards
So how does the Intelligent Design movement, which claims to be a scientifically motivated movement deal with correcting its own errors and omissions ? In the next few postings that will start with the title “Icons of ID:” I intend to explore some icons of the ID movement and show how corrections are being handled. I intend to show that the ID movement is far from self correcting when it comes to their own arguments and claims.
Niall Shanks has informed me that his recent debate with William Dembski at UCLA will be broadcast by CSPAN-2 this Saturday at 9:30 A.M. I already have my VCR programmed ...
A hot-off-the-presses article in Science describes the discovery of bilaterian fossils in the Doushantuo Formation, from roughly 570 million years ago.
Ten phosphatized specimens of a small (<180 µm) animal displaying clear bilaterian features have been recovered from the Doushantuo Formation, China, 40 to 55 million years before the Cambrian. Seen in sections, this animal (Vernanimalcula guizhouena gen. et sp. nov.) had paired coeloms extending the length of the gut; paired external pits that could be sense organs; bilateral, anterior-posterior organization; a ventrally directed anterior mouth with thick walled pharynx; and a triploblastic structure. The structural complexity is that of an adult rather than larval form. These fossils provide the first evidence confirming the phylogenetic inference that Bilateria arose well before the Cambrian.
This is exciting news, not because it revolutionizes our understanding of evolutionary history, but precisely because it is nothing surprising at all—we expect, from molecular/phylogenetic evidence, that complex animal life arose long before the Cambrian 'explosion', and what these fossils represent is a satisfying confirmation of that expectation (and they neatly fit predictions about bilaterian evolution that Erwin and Davidson made in 2002). It is actually expected, though, that bilaterian coelomates are even older than the 570 million years of the Doushantuo Formation; the last common ancestor of protostomes (arthropods and others) and deuterostomes (vertebrates and others) is estimated to have lived somewhere between 600 and 1200 million years ago.
Continue reading "Pre-Cambrian coelomate!" (on Pharyngula)
I just wanted to let everyone know that after a two-week vacation, EvolutionBlog is back. I make regular posts Sunday through Thursday evenings. Stop by for a visit!