Wrong. Evolutionary theory is not a religion, or at least, it shouldn’t be. It is a system of propositions which one can learn, apply, and test, and while so doing, “believe,” in the mundane sense that one must fix the propositions under test as provisionally true until shown to be otherwise. No scientist or philosopher should believe in the sense that he will undergo a religious conversion if he ceases to hold something to be the case for the purposes of understanding or testing it.
Parallel: an economist (monetarist) who is required by his university department to teach the Marxist theory of value. Does he believe the Marxist theory of value? Yes, if that means he understands it, how it is grounded, what it says about the world, how it fails.
Does he believe the Marxist theory of value as you, John, appear to see “belief” in evolution? Hell no. And it is unseemly, to put it mildly, to interrogate another person about his or her beliefs, as if they had any bearing on the question at hand (UCD, CD, their empirical content). That is neither science or scholarship. It’s heresy hunting.
I will have Amazon send you the Zondervan volume if you really want to see it, but I’ll need a mailing address to do so.
You make me wrong only by redefining the word “believe”. I find your entire comment an exercise in transparent sophistry. My question about your YEC opinions was intended purely to establish whether the statement “I used to believe that too” was true; clearly it isn’t, for any reasonable definition of “believe”.
Did you really intend to say “I used to understand it, how it is grounded, what it says about the world, how it fails too”?
I’m not sure I want to see it, given the quality of your argument here. But don’t you have a PDF of the chapter?
I’m preparing a response to your “statistics saves the day” argument, which I hope to post next week. I may do this as an Evolution News & Views blog, and provide the link here for further discussion, as ENV has no reader response capability.
Statistics is an integral part of hypothesis testing. You can’t do science without statistics. For example, statistics is the basis for the scientific conclusion that smoking increases the risk of lung cancer. When I do a large qPCR expression array, I use statistics as a first pass to see which changes in gene expression are significant. In mouse models, how do you tell if a drug is effective? Statistics. How many mice do we need in each group before we can say that we will see an effect, if it is there? Statistics.
Can statistics give us a false positive or false negative? YES!!! That is why repeatability and consilience is so important in science. If you test a hypothesis using multiple independent tests and methods and you see a statistically significant signal in all of those independent tests then that gives you much more confidence that your hypothesis is correct. Science is always tentative, but that doesn’t mean we hold off on making conclusions until we have 100% knowledge of everything in the universe.
Let’s note that Paul’s test is not a test of a hypothesis, and I presume it isn’t intended to be. It’s a manufactured demonstration that character change and homoplasy happen, and this supposedly disproves common descent.
Thanks for the offer to send me a copy of your book. You can save a lot of future effort, though, by making a pdf. Just scan the chapter. I’ve done that for a couple of early publications.
This is yet another reason why I’ve found most of the “ID theory” I’ve read to be philosophy and not science. There seems to be lots of confidence in the various authors’ intuition and philosophical underpinnings as various science topics are discussed but little rigorous scientific methodology, especially the intensive statistics of hypothesis testing.
Moreover, isn’t this lack of statistical rigor also the reason why “ID theory” has been around for decades but has (from what I can see) produced no impressive testable hypotheses leading to interesting scientific discoveries?
As always, these are just my impressions as a non-biologist. As a Christ-follower I’m fine with a universe created by an omniscient intelligent designer. (Even so, the Wedge Document was rather disturbing to me, for reasons which I don’t think are hard to grasp.) That said, I’d be happy to get corrected on anything I’ve misunderstood about “ID theory.”
Disproof? That would mean UCD and CD have empirical content of their own, and hence can be tested. But the randomness of answers thus far seems to indicate no discernible content, independent of what we know from other sources. The appearance of content is an illusion created by familiarity and seeing thousands of phylogenetic trees. It is impossible, however, to disprove a geometry (common descent) which is actually a formal schema into which data are fitted.
The exercises are meant to provoke (yes, irritate one into) thinking about what UCD and CD actually say about the biological world. That’s not disproving a theory at all.
That’s trying to understand UCD and CD at a deeper level than what textbooks provide.
But of course they can be tested. They’re tested all the time, though we don’t always mention it. Every test of data congruence or the significantly better fit of the data to one tree rather than others, is a test of common descent: bootstrap values, likelihood ratio tests, Shimodara-Hasegawa, etc.
The randomness of answers so far might suggest that you have masked enough of the information that the remaining data, such as they are, say very little. Incidentally, if you leave in the legend for the figure in your spiralian example, correct interpretation of the tree, even masked, shows that spiral cleavage is homologous among taxa.
I do not understand these statements. But I think you’re accusing me and other systematists of being stupid and blind. “Disprove” is not a word commonly used in science, nor is “prove”. It’s certainly possible, however, to reject a null hypothesis of no common descent with high confidence.
It is not irritating in the slightest! Had a blast with it and recommend it to everyone to test their basic knowledge of CD. Both I and @John_Harshman got the same answer without cribbing. Seems to be a reliable way if clarifying who gets the basics and who doesn’t.
I find your resistance to statistics and the claims of unfalsifiability to be very important concessions. Right now, the model that fits the data best is CD. If you don’t like that, produce a better model. This is hard. Especially because CD fits the data so well. Perhaps it is “unfalsifiable” because it is the tru structure of the data.
Moreover, why would reject statistics here, then appeal to statistics as evidence for @Winston_Ewert’s model? Which one is it? Should we be building and statistically testing models or not? You can’t have it both ways.
Regarding logical falsifiability, see your frustration and can show you the way out. Common descent is not falsifiable by purely linguistic/symbolic reasoning about the data, as philosopher such as yourself, expects. CD predicts homoplasy so homoplasy is not evidence against CD, and it predicts a tree too. Very difficult to reconcile with symbolic/Boolean logic.
What is the way out? Quantitative. The case for CD is not a qualitative case, for philosophers to go back and forth to determine the most logical answer. Rather it is driven by math, data, and the patterns of tree vs non-tree data observed in relation to other patterns. What emerges is a tightly coherent picture of the data that is so consistent with the data it is difficult to envision a better model.
Until you start thinking like a quantitative scientist none of this will make sense. What I love about your test is that it makes this clear by setting a trap that no seasoned scientist would fall into. It makes for great pedagogy. Thanks @pnelson!
Please read my statistics, UCD, and CD post at ENV next week, and we’ll resume the discussion then. For the record, I don’t reject statistics. But statistics is simply a set of mathematical tools. The problems with the empirical content of UCD and CD are not mathematical problems, however; they are biological difficulties, and throwing more math at them won’t help.
More next week; thanks to all who contributed.
P.S. to Josh: I’m as much, or more, a biologist than I am a philosopher.
