Intelligent Design. Kevin delaplante Dept. of Philosophy & Religious Studies

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1 Intelligent Design Kevin delaplante Dept. of Philosophy & Religious Studies

2 Some Questions to Ponder In evolutionary theory, what is the Hypothesis of Common Ancestry? How does it differ from the Hypothesis of Natural Selection?

3 Common Ancestry: All living organisms on Earth are evolutionarily descended from a single common ancestor. time now variation in species form Note: CA says nothing about the mechanisms that bring about evolutionary change

4 Darwin's own drawing, from Origin of Species

5 The alternative to Common Ancestry is known as the hypothesis of "Special Creation" (actually, a family of hypotheses): time now variation in species form Note: this is not a religious hypothesis

6 The Hypothesis of Natural Selection: The primary mechanism of evolutionary change is unguided natural selection. time Natural Selection (VSR): * random VARIATION of traits * SELECTION of adaptive variants through differential survival * RETENTION of selected traits through heredity variation in species form Note: Natural Selection does NOT entail Common Ancestry - these are logically independent hypotheses

7 There are many possible alternatives to Natural Selection: e.g. Lamarckian evolution -- a different mechanism "inheritance of acquired characteristics" time Lamarckism: * forms change through usage in a single lifetime * changes are inherited, passed on * nature "strives" to become more complex, adapted, perfected variation in species form Also: "self-organization" hypotheses genetic drift etc.

More Questions to Ponder... 2. Which has the strongest scientific support?

8 More Questions to Ponder Which has the strongest scientific support? i) the hypothesis common ancestry? or ii) the hypothesis of natural selection? Interesting: biology students regularly get this wrong

9 Answer: Common Ancestry - empirical evidence is OVERWHELMING Natural Selection - THAT it plays an important role in evolution is clear - that it is the PRIMARY MECHANISM responsible for the evolution of all the complexity and diversity we observe in the natural world, is a more speculative claim - however, this is the working hypothesis of standard Darwinian evolutionary theory

10 How does ID differ from creationism? Common Ancestry Natural Selection Old-Fashioned "Scientific" Creationism REJECTS ACCEPTS Intelligent Design ACCEPTS REJECTS Intelligent Design theory specifically rejects the claim that natural selection is SUFFICIENT to account for all of the complexity and diversity we observe in nature. But it accepts the "branching tree" story of the history of life on Earth.

11 The ID Argument 1. Let X be some structure or process in nature. 2. X is either the product of unguided natural processes, or the product of intelligent design. 3. X is not the product of unguided natural processes. Therefore, X must be the product of intelligent design. Most of the efforts of ID proponents are directed at supporting premise 3 for specific cases of X.

12 Example: Michael Behe - coined the term "irreducible complexity" - favorite example: the bacterial flagellum

13 ID proponents try to argue that the bacterial flagellum COULD NOT have evolved by natural selection. But this is a very difficult thing to prove. (How would you establish it?) At best, they might argue that we don't YET have a good evolutionary argument for the flagellum. But this position is vulnerable to refutation by scientific progress.

14 These arguments came under scrutiny in the recent Dover "ID" trial: Kitzmiller et al vs. Dover Area School District (2005) The Dover (Pennsylvania) school board was requiring high school science teachers to present ID as a scientific alternative to standard evolutionary theory. 11 parents sued the school board, claiming that this was unconstitutional. The case went to the US District Court in Pennsylvania. The school board tried to show that ID was science, the defense tried to show that it was not science, but religious creationism.

15 The Judge's ruling: "After a searching review of the record and applicable caselaw, we find that while ID arguments may be true, a proposition on which the Court takes no position, ID is not science. We find that ID fails on three different levels, any one of which is sufficient to preclude a determination that ID is science. They are: (1) ID violates the centuries-old ground rules of science by invoking and permitting supernatural causation; (2) the argument of irreducible complexity, central to ID, employs the same flawed and illogical contrived dualism that doomed creation science in the 1980's; and (3) ID's negative attacks on evolution have been refuted by the scientific community."

16 A final interesting question: 3. Should science reject all explanations that appeal to the supernatural? Is this a position that can be defended, or is it a philosophical dogma (as ID proponents contend)? "methodological naturalism" vs. "metaphysical naturalism"

Darwinist Arguments Against Intelligent Design Illogical and Misleading

Darwinist Arguments Against Intelligent Design Illogical and Misleading I recently attended a debate on Intelligent Design (ID) and the Existence of God. One of the four debaters was Dr. Lawrence Krauss{1}