Science reporting as it should be

By Sean Carroll | September 26, 2005 11:12 am

As PZ and Chris Mooney point out, we finally see an article about evolution and creationism that gets it right — by making it clear from the outset that evolutionary theory is well-established science and supported by mountains of evidence.

When scientists announced last month they had determined the exact order of all 3 billion bits of genetic code that go into making a chimpanzee, it was no surprise that the sequence was more than 96 percent identical to the human genome. Charles Darwin had deduced more than a century ago that chimps were among humans’ closest cousins.

But decoding chimpanzees’ DNA allowed scientists to do more than just refine their estimates of how similar humans and chimps are. It let them put the very theory of evolution to some tough new tests.

If Darwin was right, for example, then scientists should be able to perform a neat trick. Using a mathematical formula that emerges from evolutionary theory, they should be able to predict the number of harmful mutations in chimpanzee DNA by knowing the number of mutations in a different species’ DNA and the two animals’ population sizes.

“That’s a very specific prediction,” said Eric Lander, a geneticist at the Broad Institute of MIT and Harvard in Cambridge, Mass., and a leader in the chimp project.

Sure enough, when Lander and his colleagues tallied the harmful mutations in the chimp genome, the number fit perfectly into the range that evolutionary theory had predicted.

Their analysis was just the latest of many in such disparate fields as genetics, biochemistry, geology and paleontology that in recent years have added new credence to the central tenet of evolutionary theory: That a smidgeon of cells 3.5 billion years ago could — through mechanisms no more extraordinary than random mutation and natural selection — give rise to the astonishing tapestry of biological diversity that today thrives on Earth.

Evolution’s repeated power to predict the unexpected goes a long way toward explaining why so many scientists and others are practically apoplectic over the recent decision by a Pennsylvania school board to treat evolution as an unproven hypothesis, on par with “alternative” explanations such as Intelligent Design (ID), the proposition that life as we know it could not have arisen without the helping hand of some mysterious intelligent force.

Kudos to Rick Weiss and David Brown of the Washington Post. And to everyone else: see, it’s not that hard!

CATEGORIZED UNDER: Science and the Media
  • MobyDikc

    I’ve heard that Bonobos are closer to humans than Chimpanzees are.

    Can anyone clear that up definitively?

  • Lee

    The Post also reported today on a trial in federal court in Harrisburg, PA involving the Dover, PA school board’s insistence that its students be read a four-paragraph statement regarding ID:

    All of this comes as I read the following, written in 1974, from the preface to the third edition of A History of Pi by Petr Beckmann:

    “Ignorance, anti-scientific and anti-technology sentiment have always provided the breeding ground for tyrannies in the past. The power of the ancient emperors, the mediaeval Church, the Sun Kings, the State with a capital S, was always rooted in the ignorance of the oppressed. Anti-scientific and anti-technology sentiment is providing a breeding ground for encroaching on the individual’s freedoms now. A new tyranny is on the horizon. It masquerades under the meaningless name of ‘Society.’

    “Those who have not learned the lessons of history are destined to relive it.

    “Must the rest of us relive it, too?”

    Those words seem all too relevant thirty years later. Perhaps the best argument for a good science education is that an informed society is more likely to be a free society. I know that my liberal arts education provides some basis for guaranteeing the same freedoms, but I also know too many of my liberal arts friends with pseudo-scientific proclivities who are willing to give ID some credence.

  • John Landon

    Unconvinced: still no clarity over evolution versus natural selection.

  • Torbjorn Larsson

    Moby, even if gene sequencing for bonobo’s probably remains, here is a recent text that suggests that the answer is more complex than direct lineage, due to the common ancestry:

    “The control mechanism is also present in humans’ two closest cousins, the chimpanzee and the bonobo, and bears on a controversy as to which of the two species humans more closely resemble.

    Chimpanzees operate territorially based societies controlled by males who conduct often-lethal raids on neighboring groups. Bonobos, which look much like chimps, are governed by female hierarchies and facilitate almost every social interaction with copious sex.

    The DNA sequence of humans, chimps and bonobos is generally very similar, but in the section that controls response to the hormone vasopressin, the Emory researchers have found the human and bonobo versions differ significantly from that of the chimp. Though not too much can be deduced from a single gene, the result shows that bonobos should be taken very seriously as a guide to human behavior and that the chimp is not the only model, said Dr. Frans de Waal of the Yerkes National Primate Research Center in Atlanta.

    Dr. de Waal, who is writing a book, “The Inner Ape,” said the last common ancestor of all three species presumably possessed the elements of both chimp and bonobo behavior, and that humans also “unite all these aspects.” ”

    ( )

  • Torbjorn Larsson

    BTW, reflecting on the different behaviour between chimp and bonobo, perhaps reconnecting to the topic of the thread, one wonders which species creationists think are created most innocent of the two; the warmongering chimp or the sexually frivolous bonono. And neither is apparently as sinful as humans…

  • Kate

    Just finished reading Kuhn’s The Structure of Scientific Revolutions, and a quote I found particularly apt was this:

    “One of the strongest, if still unwritten, rules of scientific life is the prohibition of appeals to heads of state or to the populace at large in matters scientific.”

    Too bad IDers don’t actually care about science…

  • Clifford


    I’ve heard that too, but the distinction is quite fine as they are very very close cousins. I don’t know what the facts are though (re: DNA, etc), but behaviourally, I believe that this is motivation for a lot of interesting work by anthropologists. See my post mentioning Amy Parish’s work. I’m guessing some googling starting there might turn up something.


  • Plato

    Kate ,

    I wouldn’t rely to much on Kuhn, or you might open youself to a new debate?I’ve read it as aweel and undrstand revolution in thnking does. What it has to contend with.

    But to Lee’s comment about historical reliving of science perceptive events. Will persons experience be equally valid from insight, that one man might initiate? It takes time, and the important questions for the scientist are very much different from perspective, of those of the ordinary citizen. Lisa made this clear in the article I think. It did not mean “society” was incapable of understanding

    While it is indeed a wonder about having society fogged by the struggle by capitialism, that such extremes might see leftism far from it’s objective goals, so which person in balance would you trust having all the information availiable? That society will function consistently from those negatives, for which ever side you assign these left and right “views” to truth?

    “Education” then, becomes a interesting feature about bargaining, all the while some insight is developed from the mathematicain, nobel prize awarded and genius misused, by substitute of, “a beautiful mind.” (Clifford might be happy here?) Complex math and abstract, yet very real in a dynamical society.

    The math had then been camouflouged by real events now, and history has played itself out. It al looks very natural and before this, is was just math in somebodies beautiful mind?:)

  • Dave

    For scientists it is no doubt clear that ID is religion in disguise, and to be used as an alternative to evolution which has a wealth of evidence to support it, is laughable to even consider ID as an equal.

    Which is why I find as a layman that ID can even be taken seriously in an academic setting is a sign that education is on a decline. Of course science has always played the part of revealing new aspects of nature at first hard to accept, but in my opinion if it weren’t for religious beliefs acting as an inhibiting force, the paradigm shift from a creationists worldview to an evolutionists world view would be a much smoother process, not to mention sooner. Religion still plays the part of holding back society, instead of having freedom of religion, we should be free of religion.

  • Pingback: Rage on Omnipotent » Blog Archive » Predicting from Darwin()

  • Cian

    I agree with Dave. I sincerly believe that religion today does a world of harm and provides very few benefits to modern society. It stands in the way of intellectual freedom, demands following without good reason and – in the worst cases – lets people justify acts of violence and terror.

    Perhaps ignorance is bliss, and if I never think about the big questions then maybe that’s ok. But to me anyone who takes a serious look at this whole ID vs evolution debate can only come to one conclusion. Anything else and they are kidding themselves, and (if they’re good enough at it) perhaps even the generations that follow.

  • Jack

    Over on Lubos Motl’s blog there is a discussion of “Christian Mathematics” for schoolkids.
    Christian Mathematics!! How would that work?
    “If it takes two Roman soldiers 10 minutes to drive three nails into one Messiah, how long does it take for five Roman soldiers to drive……”

  • SM

    Perhaps the rest of you know that it is not worth engaging this Landon fellow, but here goes.

    Landon – I think what you are failing to understand is something we physicists understand phenomenologically as ‘sensitive dependence to initial conditions’. Let me explain. If there exists a mutation in a gene regulatory element within the germ line of an organism (the germ line bit plays the part of the biological initial condition), then the sensitivity to that small microevolutionary event can have immense macroscopic consequence (the examples in the Post article are pretty good I thought, especially making reference to Lenski’s work with his 12 bacterial cultures) – whether it be a new limb, or a macroscopically observable change in nutrient metabolism, or a macroscopically observable change in the growth rate of cells, etc. Now given that a macroscopic change has taken place, the change can help the organism produce more offspring than its fellow organisms, can hurt the organism into producing fewer offspring than its fellow organisms, or will have no effect at all – this is the core of the natural selection principle. The Post article actually has a very neat little paragraph that puts it better than I can:

    “Giraffes do not decide to grow long necks to browse the high branches above the competition. But a four-legged mammal on the savannah once upon a time was endowed with a longer neck than its brothers and sisters. It ate better. We call its descendants giraffes.”

    This giraffe story is exactly what is happening to Lenski’s bacteria – you should read up on that work because it is really quite interesting – as the article indicates he has observed the beginnings of speciation in the laboratory since the different bacterial cultures mutated in different ways to survive in the same stress environment.

    But perhaps you’re like me, a theorist who needs something more precise and quantitative before actually believing something (besides just ranges of acceptable harmful mutation, though that calculation is pretty impressive considering how simple the ideas are for a process so complex). So my plea to you is this: you give us some time to work out the physics of biological networks (maybe formulate a theory of nonequilibrium statistical mechanics on the way), and we might be able to talk about this from first principles :-) But the experimental results on artificial speciation are starting to come in and look good, we are really getting better at understanding how small perturbations are amplified in the highly nonlinear networks biology gives us (such as a cell’s transcriptional program), and so natural selection definitely seems to be Nature’s method.


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About Sean Carroll

Sean Carroll is a Senior Research Associate in the Department of Physics at the California Institute of Technology. His research interests include theoretical aspects of cosmology, field theory, and gravitation. His most recent book is The Particle at the End of the Universe, about the Large Hadron Collider and the search for the Higgs boson. Here are some of his favorite blog posts, home page, and email: carroll [at] .


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