More Denton: A new book (Introduction)

by David Turell , Thursday, February 25, 2016, 00:36 (3195 days ago) @ David Turell

I've been too busy to get beyond Chapter Four, but this review by a physicist is excellent:-http://www.christianscientific.org/review-of-dentons-evolution-a-theory-still-in-crisis/-"In short, his view is that there are pan-phylogenic Types, or Forms, which exist in nature, to which life spontaneously conforms. This view sounds a lot like neo-Platonism, which, following Plato, posits a spiritual world of Ideals which then instantiate themselves in nature. But Denton explicitly avoids spiritual implications and insists on this view as a purely physical and materialist theory. -***-"Denton, following Owen, draws us to look at a glaring and obvious fact of nature: that living organisms do not exist in a continuum of small differences with gradual transitions between them; rather, they exist in highly distinct types and forms, with specific identities and unique features for each type. Thus, for example, mammals all have four limbs, five digits per limb, two eyes, mammary glands in pairs, etc. These patterns persist over hundreds of millions of years despite all manner of selective pressure in different directions.-***-"First, the record strongly supports the view that new Forms appear suddenly, without precursors. This is known as “saltation”—the sudden appearance of a fully formed new structure. In all of the cases we know, the “transitional forms” between one type of organism and another do not consist of creatures with half-novelties, but rather, creatures with whole and complete novelties. Their transitional nature is identified because they have a subset of a larger set of several wholly novel features belonging to later descendents. But in each step that we see along the way, that which is new is whole and complete. The problem this creates for Darwinian evolution is similar to what is called a “topological argument” in physics. There are some things that can be continuously transformed into other things, while some things cannot.-***- "There are also more generalized topological arguments. Some molecular cycles in the cell are circular—the so-called “chicken-and-egg problems” in which element A is required to create element B, and B is required to create C, but C is required to create A. These loops therefore have the same toplogical problem of lack of continuous generation from a prior process.-***-"The transitional forms which indicate common descent also therefore create huge problems for gradual change via Darwinian selection as a mechanism. The most plain reading of the data is “descent with saltation.” This occurs at every level. New organs occur suddenly, new processes occur suddenly (such as human language), and new genes occur: in every form of life there are whole genes (known as ORFans) that appear to be utterly unique to that form, with no homolog in any other type of creature. In some cases, even when genes from an ancestor are used, they are pressed into service to perform utterly new functions via the sudden appearance of a completely new set of switches and timers.-"Denton's second argument against the Darwinist understanding of the Forms is the “robustness” of these Forms—after their sudden appearance, they endure for tens to hundreds of millions of years with little or no change. This is the case even though these Forms in many cases seem to have very little adaptive value—for example, does having five fingers or toes really make a person more fit than having six, or four? From a Darwinian perspective, the less a feature is pressured by natural selection, the more variable it should be.-***-"Another type of of robustness of the Forms is in their origin: when radically different processes give rise to the same forms. This is called “convergent evolution” in standard Darwinian evolution, but giving it a name doesn't solve the problem it creates.-***-"How could such radical saltation of new forms come about? For those adhering to intelligent design, the saltation events could be miraculous interventions. Is 100,000 too many? Why so? What is the maximum number of interventions we may impose on God?-"Denton does not invoke intelligent miraculous intervention. He favors a physical, materialist mechanism. As discussed above, his argument does not rest on having actually found such a mechanism. His argument is entirely empirical—-Comment: No room for more. The reviewer dos not believe there is a third way. Please read it all. I've used all these arguments.