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Friday, February 19, 2010

Fine Tuning and Design

There's been an upsurge in talk about the fine tuning argument for the existence of God. This is a favorite of theists since they claim that it is scientific evidence of God.

There's also been some discussion about design in nature. We're familiar with the old theistic claims that design proves God but many biologists also claim that nature looks designed—only they think that natural selection accounts for the appearance of design.

Here's Neil deGrasse Tyson poking fun at both claims and making Richard Dawkins look decidedly uncomfortable. As he says, life doesn't look terribly designed once you start paying attention.

Please, let's stop saying that life has the appearance of design. You can say that there are some features of organisms that are adaptations and these features have the appearance of design but it's silly to say that all life looks designed.

[Hat Tip: Mike's Weekly Skeptic Rant]


  1. Oh come now Larry. You're attacking a straw man here. Even people who do make optimality arguments won't say that precludes the existence of foetal mistakes. And that there is more superficial appearance of design in living organisms than, say, the surface of the moon isn't some blasphemous statement either - it's better still a statement on how life tends to be self organizing and complex, compared to other things we observe.

    If you want to do something other than attack adaptionist strawmen, the Sceptics Guide to the Universe had Simon Conway Morris on in their podcast #238. There are plenty of actual dumb adaptionalist things to take issue with there, instead of trying to find some to peg on them.

  2. Larry,
    I totally agree with your statement, "let's stop saying that life has the appearance of design."

    The notion that living organisms "appear designed" really grates on me. It's really bothersome hearing it come from the likes of Dawkins and Dennett. Knowing that neither of them is suggesting that some designer is involved makes it even more disconcerting for those of us wanting evolution to be better understood, since they are so often quote-mined by religious frauds and charlatans working to undermine science.

    I don't see hydrogen or oxygen as designed, and I don't see hydrogen peroxide, water or a hydroxyl ion as designed. I don't see amino acids, sugars, or alcohols as designed - all have been found in interstellar space. And I don't see naturally-occurring aggregations including them as designed, including those intricate aggregations we call life.

  3. It seems to be a semantic debate. I can say as an evolutionary biologist "the eye is designed for seeing" which is a stand-in for "the thing we call the 'eye' has evolved over evolutionary time into a structure with photoreceptive cells that gather light such that those individuals possessing eyes tended have higher relative fitness by virtue of possessing this structure"...or more simply "the eye is an adaptation for seeing."

    However, in both a semantic and mechanistic sense I don't find it problematic to say that "the eye has the appearance of design," in so far as I mean that natural selection was a predominant force in shaping the structure of the eye.

    And yes, I understand there are imperfections in the eye (the "backward photo receptor cells, the blindspot, etc.) but recognizing this is not incompatible with saying the structure of the eye is "designed" (by selection + existing anatomical/neurological constraints) to gather light.

    I think the better question is "design" versus "logical or good design." Natural selection can be said to engage in the former, but has no control over the latter.

    But to say all life is designed is naive and to say all life is logically designed is asinine.

  4. How do you determine that a given phenotypic feature of an organism is the product of random genetic drift?

  5. Its important to differentiate between teleology and teleonomy

  6. I guess your problem with design is mainly due to the English language.

  7. Michael asks,

    How do you determine that a given phenotypic feature of an organism is the product of random genetic drift?

    It's not easy to determine whether a certain phenotype is due to chance or selection. That's why one should avoid jumping to the conclusion that a given feature is an adaptation without evidence to support that assumption. Until you have evidence favoring one mechanism and not another you should reserve judgment.

    That's the pluralist position.

  8. The problem with this video is that the stuff is becoming old hat.
    YouTube, internet, books, - the same stuff is churned over ad nauseam. Sadly.
    To counter the inanity, but forcefulness of religion, preaching to the choir isn't getting scepticism or atheism anywhere.

    Wonder if RD was squirming because the content was not so very interesting any more? Been there, done that??

  9. Is not the biosphere what you get when living things use evolution to respond to the requirements of geophysics?

  10. "It's not easy to determine whether a certain phenotype is due to chance or selection."

    Yes, but what constitutes evidence that a phenotype is the product of genetic drift?

  11. Michael wrote, "Yes, but what constitutes evidence that a phenotype is the product of genetic drift?"

    This is a pretty complex question. In most cases, you can sug drift played a major role in shaping a trait when you have ruled out an adaptive basis for the trait. One way, for example, is to plot the trait versus some measure of fitness for individuals in a population. If there is a correlation between the trait (say height) and fitness, this can hint that selection might be operating and the next step is to find how the trait and fitness are causally associated. If there is no association, then this can be taken as evidence that the trait largely shaped by non-adaptive forces, with drift being a good candidate.

    You can also develop models of trait evolution as a function of drift and mutation, but not selection; these are usually called "neutral phenotypic evolution models" and you can compare how a simulated trait evolves over time against the observed evolutionary trajectory of a real trait.

    What I've written above is the "standard" answer. A deeper discussion of this issue is given in Chapter One of Pigliucci and Kaplan's recent book "Making Sense of Evolution: The Conceptual Foundations of Evolutionary Biology."

  12. Not sure why some url got embedded into my answer.

    It should read, " can suggest drift..."

  13. Tyson is obviously correct, and I don't think Dawkins would disagree with him.

    I believe what Dawkins is saying is that some *parts* of the universe appear designed for life, or some parts of life appear designed, and that these are unable to be plausibly explained by random chance.
    They can be explained by natural selection.

    Even if at times too eager to see selection over drift, the main point they make is that the appearance of design hints towards natural selection- not divine intervention.

    Tyson's point did not at all seem to be anti-Dawkins or anti-adaptionist, just anti-IDiot.

  14. From a 2004 journal article entitled "Positive Selection on the Human Genome:"

    "In studying human-specific traits, it is necessary to investigate the selective forces that gave rise to them. Evolutionary biologists have typically invoked two types of selective forces that shape the evolution of species. One is purifying selection, which favors the conservation of existing phenotypes. The other is positive selection (also known as Darwinian selection), which promotes the emergence of new phenotypes. Positive selection can leave a set of telltale signatures in the genes under its influence, such as the rapid divergence of functional sites between species and the depression of polymorphism within species. On the basis of these signatures, investigators are beginning to identify likely target genes of positive selection in the human genome." [Citations omitted.]

    So there apparently are some indications of selection vs. drift at the genetic level. I don't know what sort of progress has been made toward associating phenotypic changes with particular genotypic changes that have been identified as the result of selection, or of drift.

  15. OT but is Prof. Moran going to comment on Chris Mooneys' being awarded a Templeton Fellowship?

  16. No.

    It seems perfectly logical to me that Chris Mooney would be seen as an ally by the Templeton Foundation.

  17. Getting and keeping money from Templeton doesn't mean that the awardee finally publishes anything. E.g., William Dembski