Category Archives: Polemics

Polemics

How brief was the period in which the Cambrian phyla suddenly appeared?

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The Cambrian explosion refers to the sudden appearance of new body plans in the fossil record. ID proponents think that the period is between 5-10 million years at the most. Naturalists want to stretch out the period in which the body plans appear to tens of millions of years. The two sides can’t both be right. What’s the truth?

Evolution News has the answer.

Excerpt:

To establish the length of the most explosive period of innovation within the Cambrian explosion itself, Meyer cites the work of MIT geochronologist Samuel Bowring and his colleagues as well the work of another group led by Smithsonian paleontologist Douglas Erwin. The Bowring-led study showed that (in their words) “the main period of exponential diversification” within the Cambrian lasted “only 5-6 million years” (emphasis added). Meyer explains:

An analysis by MIT geochronologist Samuel Bowring has shown that the main pulse of Cambrian morphological innovation occurred in a sedimentary sequence spanning no more than 6 million years. Yet during this time representatives of at least sixteen completely novel phyla and about thirty classes first appeared in the rock record. In a more recent paper using a slightly different dating scheme, Douglas Erwin and colleagues similarly show that thirteen new phyla appear in a roughly 6-million-year window. (p. 73)

[…][T]ake a look first at the following figure that Bowring and his colleagues included in their definitive 1993 article, published in the journal Science. They use radiometric methods to date the different stages of the Cambrian period, including the crucial Tommotian and Atdabanian stages in which the greatest number of new animal phyla and classes arise. Note that the so-called Manykaian stage of the Cambrian period lasts about 10-14 million years. Note also that the main pulse of morphological innovation didn’t begin during this stage but rather during the Tommotian and Atdabanian — a period that they describe as taking between “5 to 10 million years,” and in a more detailed passage as taking about 5-6 million years.

[…]In the figure above, the Tommotian and Atdabanian stages of the Cambrian period together span only about 5 million years, starting at about 530 and ending about 525 million years ago. Bowring’s figure also depicts the total number of classes and orders present at any given time during the Cambrian period. The biggest increases in morphological innovation occur during the Tommotian and Atdabanian stages. Indeed, during this period the number of known orders nearly quadruples. Moreover, Bowring and his colleagues also make clear that this period corresponds to the main pulse of Cambrian morphological innovation as measured by the number of new phyla and classes that first appear. They note that, while a few groups of animals do arise in the earliest Manykaian stage of the Cambrian, the most rapid period of “exponential increase of diversification,” corresponding to the Tommotian and Atdabanian stages, “lasted only 5 to 6 m.y.”

You can see the figure they are reference in the Evolution News article.

Also, check out these clips that explain the Cambrian explosion:

Part 1:

Part 2:

The first clip features James Valentine, a professor of biology at the University of California who just co-authored a new book on the Cambrian explosion and is not a proponent of intelligent design.

The consensus among scientists regarding the period of time in which the new body plans appear is 5-6 million years. Biologically speaking, that’s a blink of an eye. You aren’t going that kind of complexity and innovation in such a short period of time any more than you can expect to win the lottery by buying 5-6 million tickets when the odds of winning are 1 in a googol (10 to the 100th power – 1, followed by 100 zeroes). You don’t have enough lottery tickets to make winning the lottery likely. Similarly, 5-6 million years is not enough time for naturalistic mechanisms to code brand new body plans from scratch. It would be like trying to research and write a Ph.D thesis during a single lunch hour. It’s just not enough time to produce the amount of information that’s required.

Polemics

Mark D. Linville: does Darwinian evolution make morality rational?

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Have you ever heard an atheist tell you that naturalistic evolution is an answer to the moral argument? I have. And I found a good reply to this challenge in the book “Contending With Christianity’s Critics“. The chapter that responds to the challenge is authored by Dr. Mark D. Linville. It is only 13 pages long. I have a link to the PDF at the bottom of this post.

First, a bit about the author:

Blog: The Tavern at the End of the World
Current positions:

  • PhD Research Fellow
  • Tutoring Fellow in Philosophy

Education:

  • PhD in Philosophy with a minor in South Asian Studies and a specialization in Philosophy of Religion, University of Wisconsin-Madison
  • MA in Philosophy, University of Wisconsin-Madison
  • MA in Philosophy of Religion, Trinity Evangelical Divinity School
  • MA in Theology, Cincinnati Christian Seminary
  • BA in Biblical Studies, Florida Christian College

Here is his thesis of the essay:

Darwin’s account of the origins of human morality is at once elegant, ingenious, and, I shall argue, woefully inadequate. In particular, that account, on its standard interpretation, does not explain morality, but, rather, explains it away . We learn from Darwin not how there could be objective moral facts, but how we could have come to believe—perhaps erroneously—that there are.

Further, the naturalist, who does not believe that there is such a personal being as God, is in principle committed to Darwinism, including a Darwinian account of the basic contours of human moral psychology. I’ll use the term evolutionary naturalism to refer to this combination of naturalism and Darwinism. And so the naturalist is saddled with a view that explains morality away. Whatever reason we have for believing in moral facts is also a reason for thinking naturalism is false. I conclude the essay with a brief account of a theistic conception of morality, and argue that the theist is in a better position to affirm the objectivity of morality.

And here’s a sample to get your attention:

But even if we are assured that a “normal” person will be prompted by the social instincts and that those instincts are typically flanked and reinforced by a set of moral emotions, we still do not have a truly normative account of moral obligation. There is nothing in Darwin’s own account to indicate that the ensuing sense of guilt—a guilty feeling—is indicative of actual moral guilt resulting from the violation of an objective moral law. The revenge taken by one’s own conscience amounts to a sort of second-order propensity to feel a certain way given one’s past relation to conflicting first-order propensities (e.g., the father’s impulse to save his child versus his impulse to save himself). Unless we import normative considerations from some other source, it seems that, whether it is a first or second-order inclination,one’s being prompted by it is more readily understood as a descriptive feature of one’s own psychology than material for a normative assessment of one’s behavior or character. And, assuming that there is anything to this observation, an ascent into even higher levels of propensities (“I feel guilty for not having felt guilty for not being remorseful over not obeying my social instincts…”) introduces nothing of normative import. Suppose you encounter a man who neither feels the pull of social, paternal or familial instincts nor is in the least bit concerned over his apparent lack of conscience. What, from a strictly Darwinian perspective, can one say to him that is of any serious moral import? “You are not moved to action by the impulses that move most of us.” Right. So?

The problem afflicts contemporary construals of an evolutionary account of human morality. Consider Michael Shermer’s explanation for the evolution of a moral sense—the “science of good and evil.” He explains,

By a moral sense, I mean a moral feeling or emotion generated by actions. For example, positive emotions such as righteousness and pride are experienced as the psychological feeling of doing “good.” These moral emotions likely evolved out of behaviors that were reinforced as being good either for the individual or for the group.2

Shermer goes on to compare such moral emotions to other emotions and sensations that are universally experienced, such as hunger and the sexual urge. He then addresses the question of moral motivation.

In this evolutionary theory of morality, asking “Why should we be moral?” is like asking “Why should we be hungry?” or “Why should we be horny?” For that matter, we could ask, “Why should we be jealous?” or “Why should we fall in love?” The answer is that it is as much a part of human nature to be moral as it is to be hungry, horny, jealous, and in love.3

Thus, according to Shermer, given an evolutionary account, such a question is simply a non-starter. Moral motivation is a given as it is wired in as one of our basic drives. Of course, one might point out that Shermer’s “moral emotions” often do need encouragement in a way that, say, “horniness,” does not. More importantly, Shermer apparently fails to notice that if asking “Why should I be moral?” is like asking, “Why should I be horny?” then asserting, “You ought to be moral” is like asserting, “You ought to be horny.” As goes the interrogative, so goes the imperative. But if the latter seems out of place, then, on Shermer’s view, so is the former.

One might thus observe that if morality is anything at all, it is irreducibly normative in nature. But the Darwinian account winds up reducing morality to descriptive features of human psychology. Like the libido, either the moral sense is present and active or it is not. If it is, then we might expect one to behave accordingly. If not, why, then, as a famous blues man once put it, “the boogie woogie just ain’t in me.” And so the resulting “morality” is that in name only.

In light of such considerations, it is tempting to conclude with C. S. Lewis that, if the naturalist remembered his philosophy out of school, he would recognize that any claim to the effect that “I ought” is on a par with “I itch,” in that it is nothing more than a descriptive piece of autobiography with no essential reference to any actual obligations.

When it comes to morality, we are not interested in mere descriptions of behavior. We want to know about prescriptions of behavior, and whether why we should care about following those prescriptions. We are interested in what grounds our sense of moral obligation in reality. What underwrites our sense of moral obligation? If it is just rooted in feelings, then why should we obey our moral sense when obeying it goes against out self-interest? Feelings are subjective things, and doing the right thing in a real objective state of affairs requires more than just feelings. There has to be a real objective state of affairs that makes it rational for us to do the right thing, even when the right thing is against our own self-interest. That’s what morality is – objective moral obligations overriding subjective feelings. I wouldn’t trust someone to be moral if it were just based on their feelings.

The PDF is right here for downloading, with the permission of the author.

Polemics

Dr. Walter Bradley explains the requirements for life of any imaginable kind

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I was talking to a friend of mine earlier this week about my experiences as an undergraduate in college, and it turns out that both of us relied on the same web site to get us through our late teens and early 20s. The web site is Leadership University, and it features articles on many different topics from Christian professors.

Here’s an article by famous mechanical engineering professor Walter Bradley to explain what it takes for a universe that supports complex, embodied life.

Excerpt:

We teach mechanical engineering students to begin the design process by specifying as clearly as possible the “needs statement” for their project. Then, the assignment for the semester is to develop a design solution that accomplishes the “need(s)” specified for the project. In similar fashion, the minimal needs to be satisfied for a universe to be capable of supporting life of any imaginable type, not just life as we know it, must be identified. Like our automobile illustration, many of the specifications will necessarily be interrelated to make a functional universe. From this essential “needs statement” we can then see how these needs (or design requirements) are met in our universe. We are essentially doing reverse engineering, constructing the blueprint backwards from the product (like an illicit manufacturing company copying a competitor’s product). Only then will we be ready to entertain Dawkins’ question, “Are there many ways in which these requirements could be satisfied within nature?” Or are the conditions so unique and interrelated that their collective satisfaction by accident would be a “miracle” in its own right? Let us then begin by drafting a “needs statement” for a habitable universe. Then we shall see how these requirements are satisfied in our universe.

Needs Statement for a Suitable Universe

An abbreviated list of requirements for a universe suitable to support life of any imaginable type must include the following items:

  • Order to provide the stable environment that is conducive to the development of life, but with just enough chaotic behavior to provide a driving force for change.
  • Sufficient chemical stability and elemental diversity to build the complex molecules necessary for essential life functions: processing energy, storing information, and replicating. A universe of just hydrogen and helium will not “work.”
  • Predictability in chemical reactions, allowing compounds to form from the various elements.
  • A “universal connector,” an element that is essential for the molecules of life. It must have the chemical property that permits it to react readily with almost all other elements, forming bonds that are stable, but not too stable, so disassembly is also possible. Carbon is the only element in our periodic chart that satisfies this requirement.
  • A “universal solvent” in which the chemistry of life can unfold. Since chemical reactions are too slow in the solid state, and complex life would not likely be sustained as a gas, there is a need for a liquid element or compound that readily dissolves both the reactants and the reaction products essential to living systems: namely, a liquid with the properties of water.
  • A stable source of energy to sustain living systems in which there must be photons from the sun with sufficient energy to drive organic, chemical reactions, but not so energetic as to destroy organic molecules (as in the case of highly energetic ultraviolet radiation).
  • A means of transporting the energy from the source (like our sun) to the place where chemical reactions occur in the solvent (like water on Earth) must be available. In the process, there must be minimal losses in transmission if the energy is to be utilized efficiently.

Unless ALL of these conditions and many more not included in this list are met, we would have a universe that would preclude the possibility of conscious, complex life forms. However, it is possible to meet all of these conditions for the universe and still not necessarily find a suitable habitat in the universe for complex, conscious life. Therefore, we might say that the above requirements for our universe are necessary, but not by themselves sufficient, conditions for a habitat suitable for complex human life. Next we try to identify the additional conditions within such a suitable universe that would provide a place of habitation for conscious, complex life.

Needs Statement for a Habitat Place in the Suitable Universe for Complex, Conscious Life

An abbreviated, but illustrative, list of additional requirements must be specified for a place of habitation in this universe. First, we need a star that is located in a relatively “quiet” region of the universe (e.g., not too many neighbors that are producing high intensity, sterilizing radiation). This star needs to have its highest intensity of radiation in the range that is suitable to drive the chemical reactions essential to life without destroying the products of these reactions. Furthermore, this star needs to have a very special satellite within its solar system. A partial list of the requirements this satellite must meet include:

  • a planet or moon that is terrestrial–or, solid rather than gaseous;
  • a temperature range suitable to maintain the universal solvent as a liquid rather than a solid or gas;
  • just the right concentration of heavy (radioactive) elements to heat the core of the planet and provide the necessary energy to drive plate tectonics, to build up land mass in what would otherwise be a smooth, round planet completely covered with solvent;
  • just the right amount of solvent (carefully coupled to the plate tectonics activity) to provide a planet with similar proportions of its surfaces as oceans and land mass;
  • just the right protection from the destructive forces in nature such as radiation and asteroids over a reasonable amount of time; and
  • just the right stabilized axis tilt and angular velocity to give moderate, regular, and predictable seasons and moderate temperature fluctuations from day to night.

While one is temped to think that these requirements are easily met, given the large number of stars, it should be noted that there are few places in the universe sufficiently free of sterilizing radiation to provide a suitable solar system. The number of candidate “neighborhoods” is further reduced by the requirements of a sun with the right amount of mass to give the right electromagnetic radiation spectrum. Furthermore, the occurrence of a suitable satellite in conjunction with such a star is even more problematic. Only the earth in our solar system of sixty-two satellites meets the above requirements for a “home” (earth) in safe “neighborhood” like our sun and solar system, which are well placed in a quiet place in a suitable universe as described above.

In the next sections, we will see how these universal and local “needs” (or design requirements) are met by: the specific mathematical form encoded in nature, the exact values of the universal constants in our universe, and the remarkable “coincidence” that initial (or boundary) conditions are exactly what they must be. We will also see that the “evolutional” or developmental path that our universe navigated is consistently remarkable, making the origin of our “Garden of Eden” all the more wondrous and enigmatic.

If you want to see the next sections of his article, you can click here to read the rest.

Why is this important? It’s important because a lot of people on the other side want to dismiss the fine-tuning argument by saying that if the fundamental constants and quantities specified in the Big Bang had been different, then the results would be a universe that permits life of some other kind. That’s false. If you vary the constants and quantities, you lose things that are required for any conceivable kind of complex life. You can’t form stable, metal-rich stars. The universe recollapses into a hot fireball. You have only hydrogen. You have NO hydrogen. It’s not just that people have some ridges on their noses or maybe an extra pair of arms. It’s that there is no life, period.

This is important. There are minimum requirements for life of any conceivable kind, and messing with the fine-tuning of the universe destroys the ability of the universe to provide those minimal requirements. Naturalists can smirk and shrug this off, but this is the science that we have today and we have to deal with it.