is evolution a repeatable science?

January 5, 2009

Most people familiar with the Wedge Document created for the Discovery Institute at its inception, know that it’s a battle plan for advancing creationism in science classes through a tactic called “teaching the controversy.” Creationists portray evolution as a hotly debated topic within the scientific community and insist that intelligent design provides an equally scientific alternative. Another, less used tactic is declaring that evolution isn’t a scientific theory but a circular argument preached with the zeal of a religion. Evolution, they say, isn’t repeatable under laboratory conditions and if it’s not repeatable, it’s not science.


Oh the irony! The biggest charge levied against creationism by scientists is that a designer or a deity isn’t repeatable in a lab and is subjectively defined, therefore creationism isn’t science. If this isn’t a textbook case of mental projection on the part of the creationists, I don’t know what is. Why? Because if we use the proper principles of evolution rather than the quasi-Lamarckian fallacy presented by creationists in their lengthy and passionate denials, we can put every one of the mechanisms vital for evolution to take place to the test in an objective, repeatable form, starting with mutations and ending with natural selection and speciation.

Mutations are supposed to be random changes of the genetic code which happen when a DNA strand is replicated. When we don a white coat and test how accurately DNA is replicated, we’ll see that on average, every 100,000 base pairs or so, there’s some sort of error. Base pairs are missing, doubled up or the wrong base pairs are copied. We can take any organism with DNA, study its genome before and after replication, note all the errors and do it again and again. As it continues to replicate, we’ll see that the mutations change from replication to replication and there doesn’t seem to be an order in which the mutations take place. Hence, random mutations are repeatable under laboratory condition and are hence, science.

But hold on, what about whole limbs and different body parts? Ah, that’s where the lab reigns supreme because we can not only observe the biology at work, we can control it. By simulating signals from Hox genes and artificially duplicating active areas of stem cell development in any embryo, we can create new pairs of arms and legs, even chimeras and conjoined twins. We can see it just happen in a small percentage of cases and we can replicate what we see in a normal embryo with the same result. It’s not just repeatable science, it’s a bona fide experiment with every trapping of the scientific method to it. What do you think scientists do with fruit flies in a darkened laboratory, hunched over their tiny eggs? They conduct experiments on Hox genes and genetic toolkits that control the organism’s development and body plan.

Next we can tackle natural selection. We can catalogue animals in a given population and their genetic makeup. Then over generations, we know how many survived, how many died and how many got the chance to pass on their genes. A few dozen generations later, we can take a DNA sample from the resultant population and compare it to the original samples taken at the start of the experiment. What we’ll notice is a genetic drift towards the genomes of the survivors in the original population. We can see this in fruit flies, humans, birds and just about any animal we’ve studied extensively. Once again, it’s repeatable, testable science.

Finally, we can take on the biggest test of evolution, speciation. How do we prove that a species can split into two different, non-interbreeding populations? Easy. Just repeat the experiment to tack natural selection and genetic drift but split your original population and put the halves in different environments. Different animals survive in different conditions and over a very long stretch of time, you can track the cumulative differences. A big enough difference makes them two different species and over time, they will drift so far apart from each other, producing any sort of hybrids would be impossible. Take grizzlies and polar bears for example. The two don’t like each other and mate so rarely, only one polar/grizzly hybrid is known to exist and the few rumored to be out there are just Arctic tales told over a campfire. But they started out as one species, proven by the fact that they can hybridize. We see it nature, we know how to replicate it with an experiment. Bottom line, it’s testable, repeatable science.

In creationist circles, there’s an overwhelming desire to call evolution a religion because that’s how they view it. To them, science is the gospel of atheism designed to undermine their belief system in favor of another. This is why they approach it the way religious zealots deal with any competing faith. Just like they believe that their religion holds truths and is repeatable because hundreds of millions of people think the same way, they disregard the actual science behind a complex theory and use the old religious rallying cry of my-truth-is-truer-than-your-truth. But even more perplexing and alarming is the fact that because evolution isn’t aligned with a book they consider sacred, it must be wrong. How much of their faith comes from a book and how much of it comes from the heart? Even the Bible advises us to believe with our hearts but seek the truth with our eyes. Denying the repeatable nature of evolution isn’t seeking the truth with one’s eyes. It’s closing one’s eyes to a small part of a truth we’re just beginning to unravel.

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  • Matt

    Nicely thought out post.

    Good work.

  • DTV

    The problem isn’t just with microevolution, what your experiments deal with. The problems is that many creationists have problems with the concept of macroevolution, the changing of dinosaur to bird, for example, despite the evidence of transitional forms. How could we experiment with that?


  • Greg Fish


    I’ve written before about transitional fossils (as well as after this post). There’s certainly evidence of transitional forms, it’s just being fervently denied either for the sake of denial or because creationists ascribe to their own definitions of the theory of evolution which allow them to reject the evidence more easily.

    With the second experiment, you can turn birds back into dinosaurs within certain size constrains. It’s already being done.

  • Lone Wolf

    People buy into such arguments cause when it comes to science education, the schools in this country are failures. People think that “re[eatable” means that you have to repeat “it”. They don’t know that “repeatable” means an experiment or study has to be repeatable, not the event, thing or action.

    If the schools would just teach the scientific method.

  • really?

    if “repeatable” means an experiment or study has to be repeatable, that is not science.

    Hypothesis: 2+2=4 is an equation that is created by flying invisible cows.

    That is repeatable and testable.

    Is that science?

  • Greg Fish


    I think youre confusing the requirements for a scientific theory with the stages of the scientific method. If your hypothesis is that theres an equation created by flying cows and youve designed an experiment to prove or disprove that assertion, its scientific, no matter how odd it sounds. Ok, so theyre invisible, but you can still prove the existence of an object invisible to us by its detecting its effects on the surrounding environment.

    Now, if you say that theres a equation created by flying cows and you know it for certain because you were told so in a dream you once had or you read it in some book then thats not scientific.

  • jypson

    It must be very frustrating dealing with creationists and ID zombies tearing apart the scientific method to try and ‘prove’ their beliefs. In my profession, we have our own cycle, and its never diluted or substituted. Planning Collection Processing Analysis/Production Dissemination – and repeat.

  • Loeck

    You’ve addressed almost all of my questions/misunderstandings, except for one. How would a fish that has evolved to the point where it has “feetfins” and can go on land and is at the point that it’s basically amphibian,but it’s instincts tell it to stay under water and not go out of water, and so all of it’s land walking abilities are rendered useless because the animal doesn’t want to go on land, how is this an advantage, or on the flip side it has the instincts but cant breath air?

  • Earl

    A great difficulty for evolution is where did the basic materials for evolution come from?Evolution depends upon a “Big Bang” creating the basic building block of the Universe(hydrogen) from nothing.Nothing means NOTHING! Something cannot come from nothing without a cretive power bringing it to pass.All mumbo-jumbo about “quantum fluctuations” is fairy tale nonsense.All the laws of physics as well as common sense militate against it.This can only believed by adherents of evolution as a religion.Boyle’s Law proves that a cloud of hydrogen would only disperse.Also,there must be chemical evolution to form heavier elements.Even the hydrogen bomb could not form an element heavier than helium.Finally,where did the angular momentum come from as virtually everything in the Universe,as well as the Universe itself, is spinning?

  • Greg Fish

    “Evolution depends upon a “Big Bang” creating the basic building block of the Universe(hydrogen) from nothing.”

    And you’ve now demonstrated that you a) don’t understand that you can’t explain one theory with another or apply it where it wasn’t meant to go, and b) don’t know that the Big Bang was not an explosion out of nothing and is not how it’s defined in cosmology.

    But thanks for playing and feel free to try again when you find a clue!

  • Rob

    First of all, I will explain that I agree, creationism is not a science, it is a belief, which cannot be proven. Second of all I am a believer, not a scientist, but I believe based on the life that I’ve seen and I seek truth and I have a few questions: Even if there are random repeatable mutations, which I don’t deny; how many of them are usable and beneficial to the organism? If species have been evolving over the past 100 million years, shouldn’t there be overwhelming samples of transitional fossils, instead of a random breaking edge one here and there? We should be finding these things all over, in every continent, even in our own back yards.

    Limb replication and Natural Selection are not exclusive to the theory of macro evolution. Natural selection is merely the changing of dna within a species, as in breeding, we never observe breeding one kind of organism into another, only vastly different breeds, as in dogs. Genetic drift and the inability to mate, doesn’t necessarily change a species into a new species, because there are physical restrains involved like size and appeal. Polar and Grizzly are not different species but two vastly different breeds within the sam species.

    I understand that the big bang doesn’t claim everything out of nothing and cosmology doesn’t explain the origins of space and time, because it can’t, we can’t repeat or grasp such things.Science cannot “prove” the past, because time is a specific, relative variable. The past can only be believed, not proven. If a person won’t believe solid evidence like yesterdays newspaper, then thats up to them. I wonder how us, humans on our little planet, in our little solar system, in our little galaxy can conclude from our tiny perspective that we know how the universe was formed, that a higher being, God doesn’t exist and couldn’t have been involved in creating this universe. We are not even a spec in the dust of our own galaxy, much less the universe. Criticize me all you want but the truth is the more we learn, the more we learn what we don’t understand…