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I was just listening to a caller on an old episode of The Atheist Experience (about 1 hr 3 min in – I love that show). The caller was quite disingenuous, asked Matt and Jeff what their degrees were (they have none), went on to present his own bona fides (computer programmer “degree”), and then asked what their proof was for the origins of the universe. Matt headed the caller off at the pass quite nicely. He said (quite rightly) that that did not matter, since even if we had no explanation this lends no credence to any other hypothesis. Competing ideas are simply not necessarily equal in terms of their truth value, and just because someone considers one false does not make their own idea true, unless we are speaking of a true dichotomy (which this most definitely is not). A further problem is the caller desired “proof”. The only place the word “proof” is applicable is in mathematics and logic. In the natural sciences, conclusions are drawn based on evidence – we do not deal in “proof”.

The caller also committed another fallacy, claiming that if we do not observe something directly then it is not scientific. We did not observe the universe come into existence, therefor we can not say that Big Bang model is correct. That is patently absurd. All experiments – even those in a laboratory – are indirect measurements. When we mix chemicals in order to observe how they react, we are not directly looking at the individual molecules. We might see a color or temperature change in the mixture, but does the fact that these are indirect observations of what is going on invalidate the idea that a reaction has taken place? Even if we identify the product, it is still historical even if it happened only a few minutes ago. Historical evidence is simply another type of indirect observation. Jeff made a good point that since we have only known of Pluto’s existence for about six decades – far less than it takes Pluto to make a complete orbit – the caller must conclude that we can not know that Pluto orbits the sun!

Think of it this way. You come home to find the family cat looking guilty in front of an overturned plate of unsecured leftovers. There are many possible explanations for this scene, but are they all equally likely? Perhaps it was death rays from Mars – in a plot by Martians to assassinate my cat who is secretly the only thing standing between us and a planetary invasion – missed, the rays striking the plate on the counter sending it careening onto the floor. Does anyone really think that this explanation is on a par with the possibility that the cat (in its gastronomic zeal) pushed the plate off the counter and followed it onto the floor to finish off the leftovers? I don’t think so. Yet each explains the scene fully.

The truth is, each and every one of us uses historical evidence daily, yet this caller chose to claim that in this specific instance – coincidentally one in which he found it convenient to do so – one could not validly arrive at a scientific conclusion in this manner. This is obviously nonsense. Certainly, the caller is correct in one aspect – that we did not directly observe the Big Bang event. But this event gave rise to observable consequences. From astronomical observations (such as Hubble’s observation of a red shift proportional to the distance a galaxy is from ours) and particle physics cosmologists have built a model to explain what they see. Even more importantly, this model makes testable predictions – observations that weren’t been made at the time the model was proposed but what would be expected to be observed if we look, such as the cosmic background radiation and relative abundance of primordial elements such as hydrogen, helium and lithium.

Evolution as Darwin presented it similarly relied on historical evidence (it no longer does – evolution is being observed in action, such as the Pod Mrcaru lizard introduced onto the Croatian island in 1971 for this specific purpose). Predictions came fast and furious. It was hypothesized that horses evolved from mammals with more than one toe. This hypothesis was rapidly followed by its confirmation, particularly from North American fossil finds. There have been thousands of such finds. The whale evolved from a land mammal and its fossil lineage is incredibly well defined, right down to our ability to see how the position of the nasal passage moved from the front to the top of the head. Lineages derived from comparative morphology match those derived measuring genetic differences as predicted by the modern synthesis. These evidences all confirm predictions made by evolutionary theory and thus strengthen it greatly.

In short, conclusions based on historical evidence are perfectly valid and scientific. The only difference between doing an experiment in a lab and drawing conclusions from historical evidence is that there are tighter controls and a greater ease in adjusting variables in former. That’s it. The Earth, the universe- these are laboratories and nature itself has done the experiments. In both situations we are observing the results and explaining them. Rejection of this always seems to be associated with an incompatibility between closely-held ideas and reality. For those who deny evolution and Big Bang cosmology, grow up. If you think that when science conflicts with a held belief, so much worse for science, then you have abandoned reason and the only thing left which might get through to you is mockery.

Matt had as good a response. He hung up on his ass.

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9 Comments

  1. Well put. Does this show come in podcast form? If so I will have to add it to my routine.

  2. Hell, ya. It comes in various formats, including video and mp3. The archive is available here. Matt et al also do a non-call in podcast called The Non-prophets, which is also really good. The Atheist Community of Austin is very diligent about keeping the archive up-to-date. I arranged to have Matt give a talk over Skype later in April, which I look forward to.

  3. The show completely rocks. So does The non-prophets. I don’t feel like my weeks are complete until I’ve had my dose!

    thanks for this…very well put!

  4. Good argument. Thank you.

    Except, what happened to the lizard on the island of Pod Mrcaru, I would not call evolution but genetic adaptation. Well, I know for most evolutionary biologists this is just the same though not for me as if brought back home all changes will reverse probably, and it will not result in a new species, a more capable lizard, or a more complex ecosystem.

    Please allow to add an other thought to your historical argument. As you correctly stated, in science we accept to be true what is the most likely and the most parsimonious explanation, not what we sense as our senses can be tricked. Just to give a striking example: a man feeling his toes of an amputated leg.

  5. Except, what happened to the lizard on the island of Pod Mrcaru, I would not call evolution but genetic adaptation. Well, I know for most evolutionary biologists this is just the same though not for me as if brought back home all changes will reverse probably, and it will not result in a new species, a more capable lizard, or a more complex ecosystem.

    Evolutionary changes cannot reverse. It would be possible for the lizards to converge to their cousins in many respects, but this requires further genetic changes. Saying that evolution can reverse is like saying that when Michael Jackson did the “Moonwalk” he was moving backwards in time. In short, this is a new species. I highly doubt that this population would interbreed with the parent one. All speciation is is a sufficient amount of genetic change between an isolated sub-population and its parent population. This kind of change is more than enough to have produced mammals from reptiles, for instance (extraordinarily well documented in the fossil record, by the way).

    But even if we re-introduced these lizards to the parent population, they would still end up as a separate species. These new lizards – even after a mere three decades – are on a different evolutionary path. That’s why evolution is a bush, not a ladder. Historical contingency is an extremely important concept in evolution, and is responsible for the rather uneconomical anatomical oddities in our own bodies (the weird wiring of our retinas and the convoluted paths of the vegas and phrenic nerves, for instance). Your term “more capable lizard” is disconcerting. Evolution is not a path to perfection, whatever that word means. Both the parent and new species are each well-adapted for their respective ecological niches. There is no such thing as a “more capable lizard”.

    And, yes. “Genetic adaptation” is indeed evolution, and the evidence that genetic change produces new species is overwhelming. Presumably, your term “genetic adaptation” describes changes in the genome. If a species is largely defined by its genome, why would you think that significant changes to it would not result in a new species? That perplexes me.

    There are lots of books out there not written by the liars (I don’t use this term loosely or without a lot of thought behind it) of the Disco Institute that discuss the evidence.

    Please allow to add an other thought to your historical argument. As you correctly stated, in science we accept to be true what is the most likely and the most parsimonious explanation, not what we sense as our senses can be tricked. Just to give a striking example: a man feeling his toes of an amputated leg.

    Which is exactly why I define knowledge as that which can be independently verified. That’s what science does – it uses various methods of verification to increase our confidence that what we call knowledge can indeed be legitimately called knowledge.

    Let me ask you a question: if you had a missing limb, how would you know that your senses had deceived you, and that the sensation of feeling a part of that missing appendage was only a vestige of what was once there? The ironic thing is that it is impossible to come up with an example of where our senses are being deceived without knowing through independent verification that they are being deceived. Of course, it is possible that we are just brains in vats, but then anyone claiming this might as well be a solipsist and I openly mock them.

    Not only is the toolbox we call science the best path to understanding the universe, it is the ONLY way that can verifiably allow us to do so.

  6. Evolutionary changes cannot reverse.

    Exactly! And that’s why I’d not call it evolution as I’m convinced these changes can reverse. Admittedly this is but supposition. One should prove it experimentally. I hope someone will, and I’m eager to learn the result. Besides there exists a similar example already. As you are familiar with evolution you probably know the stickleback example, the variation in lateral plate pattern and number probably depending on predators (http://www.jstor.org/pss/4535321).

    However, there are two ways that evolution actually occurred in this lizard example. Please allow to outline this on my own blog in more detail. Thank you for your inspiration, indeed, and feel free to answer on your blog. I will follow it.

  7. Exactly! And that’s why I’d not call it evolution as I’m convinced these changes can reverse. Admittedly this is but supposition.

    Let me put it another way… “Genetic adaptation” can not be reversed, either. I’m not sure how the stickleback example (I am familiar with it) applies here. The Pod Mrcaru lizards have actually evolved genes encoding new enzymes which allow them to follow a totally different diet from the parent population.

    In sticklebacks, the changes in fin rays occur through developmental gene timing. Sean Carroll describes this in detail in The Making of the Fittest. And these changes won’t reverse (I mean reverse in its truest sense), though it is possible that changes in fin rays and armor plates can converge to the older version of the fish. But this isn’t a reversal in the sense that the mutations all change back to the way they were. That is impossible. Such convergence can only happen through further gene changes.

    It would be an interesting experiment to re-introduce them to the parent environment. But there’s a pretty good chance that they would die out. The change in dietary needs worked okay one way, but changing it back may not be possible.

  8. |But this isn’t a reversal in the sense that the mutations all change back to the way they were. That is impossible. Such convergence can only happen through further gene changes.|

    Exactly. That’s why so many species on earth can’t back breed. Think about it: Two species that are closely related but that live in very different environments (or were separated for quite a long time) would encounter complications if they bred. And in most cases, they can’t. Too much difference in genetic information. (Of course, humans have experimentally mixed all kinds of different species and usually, if successful, produce sterile offspring – which sort of proves the point).

    An example more personal to us is the Neanderthal genome project. The results show that Neanderthals and humans, although they coexisted, were quite different. To illustrate, most humans differ by about 8.0 substitutions in their mitochondrial DNA, while humans and chimps differ by about 55.0 substitutions. Humans and Neanderthals differ by about 27.2 substitutions.

    Anyway, Paul, you should really read Dawkins’ latest book, “The Greatest Show on Earth.” It’s a treatment of the evidence so far for evolution by natural selection. It might answer some of your questions (although, for some strange reason, he doesn’t include the Neanderthal genome project in his book).

    • Over the last several years there has been a spate of good lay books on the subject of evolution. Jerry Coyne’s Why Evolution is True, Sean B. Carroll’s Endless Forms Most Beautiful and The Making of the Fittest, Neil Shubin’s Your Inner Fish, Daniel Fairbanks’s Relics of Eden. Not long ago about the only book you could find was Dawkins’s The Blind Watchmaker, perhaps the best one ever written for a lay readership.


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