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Friday, July 25, 2014

Evolution and Falsification

Posted by jlwile on June 23, 2010

Sir Karl Popper
from http://en.wikipedia.org/wiki/File:Karl_Popper.jpg

Dr. Hunter had a post on his blog a few days ago dealing with evolution and whether or not it could be falsified. As he states, falsification is an incredibly important part of science. Indeed, the great philosopher Sir Karl Popper pointed out that science cannot prove anything. Instead, the best science can do is pile up evidence to support a theory. The more evidence that supports the theory (and the less evidence that opposes the theory), the more reasonable it is to believe the theory. However, the theory can never be proven.


In Popper’s view (and I agree with him), while you can never prove a scientific theory, you should be able to demonstrate it to be incorrect. In other words, a scientific theory should be falsifiable. There should be the possibility that some discovery would end up demonstrating that the theory is false. If a scientific theory can accommodate any data, it is not a scientific theory. This, of course, makes sense. If a theory is so plastic that it can be molded to fit any data, it is definitely not scientific.

Dr. Hunter says that evolution is not falsifiable because it is a negative argument. As he puts in in the post mentioned above:

Evolution is, and always has been, motivated by failures of creationism and design. If god did not design or create this world, then it must have evolved. Somehow. Evolutionists perform research to try to figure out how evolution could have happened, but it must have happened—that much they know. That is a metaphysical position, not a scientific position, based on a negative argument. It is not falsifiable.

While I agree with the last sentence in that quote, I don’t agree with anything that comes before it.

I don’t think evolution is a negative argument. I don’t think it is simply the result of people thinking God didn’t create. Now don’t get me wrong. There are probably plenty of evolutionists who believe in evolution simply because they don’t want to believe that God created. That’s fine, but it’s not very scientific. It’s also not representative of the majority of evolutionists out there. I think evolutionists believe in evolution because they see evidence for it. Similarities between different organisms, for example, represent (in their minds) strong evidence for common ancestry.

Given that evolution isn’t a negative argument, is it falsifiable? I think that it initially was. Darwin made all sorts of predictions, but many of them have been falsified. In order to “save” evolution, however, evolutionists simply started adding caveats to “explain around” the falsifying data. As a result, we now have an evolutionary theory that is so plastic it can be molded around any kind of data. This makes it not falsifiable, and thus not scientific.

To give you an example of the flexibility of evolutionary theory, lets start with something Darwin said:

If it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species, it would annihilate my theory, for such could not have been produced through natural selection.1

Of course, there is a common example of just such a situation. Indeed, I fight this common example every spring. It is the backyard dandelion. There are many species of dandelion, and most of them reproduce sexually. However, the common backyard dandelion does not. It’s only mode of reproduction is asexual.2

Do you see the problem with this? The common dandelion plant produces flowers, and those flowers produce nectar. Insects love to eat that nectar. Now if the common dandelion reproduced sexually, this would benefit the dandelion. The insects would get pollen on them, and when they went to the next flower, they would transfer that pollen to the next plant, and that would allow the two plants to sexually reproduce. However, the common backyard dandelion doesn’t sexually reproduce, the nectar it produces gives it no benefit. The nectar benefits the insects only. Thus, here is a plant that produces nectar, and that nectar benefits only other organisms. This, of course, is exactly what Darwin says would “annihilate” his theory.

Of course, evolutionists cannot let that happen, so they have to come up with some caveat to fix the situation. As a result, they say that the common dandelion did have a sexual mode of reproduction at one time, but it was eventually lost. Thus, the nectar production is a left-over remnant of a mode of sexual reproduction that once existed.

In the end, I have no problem with that argument. It seems very reasonable. However, please realize what it implies, because it will become important in a moment. The dandelion expends a lot of energy producing the nectar that gives it no benefit. Thus, to believe in this explanation, we must believe that natural selection allows an organism to be incredibly wasteful – it keeps around a vestige from a system it no longer has, regardless of the fact that it is expending a huge amount of energy to keep it.

Why is this a problem? Well, let’s look at another situation. Apes have an excellent sense of smell, but their eyesight leaves a bit to be desired. Humans have much better eyesight than apes, but they have a worse sense of smell. Because of the similarities between apes and humans, it is assumed that they both shared a common ancestor. In addition, it is expected that this ancestor was rather “ape-like.” Most evolutionists, then, assume that through the process of evolution, humans developed better eyesight, but their sense of smell actually got worse.3

Once again, there is a reasonable explanation for this as well. If the common ancestor of apes and humans lived mostly in the woods, the sense of smell would be more beneficial than the sense of sight. Over the course of evolution, however, if humans moved out of the forests and onto the plains, the sense of sight would be more important. Thus, natural selection would select for better sight, and since organisms can’t afford to be wasteful when it comes to resources, it would select against the apelike sense of smell. As a result, humans developed better eyesight, and they ended up with a worse sense of smell in order to conserve resources.

I have no problem with this argument, either. As I said before, it is reasonable. The only problem is that it is incompatible with the explanation regarding the dandelion. In the case of the dandelion, natural selection allows it to waste an enormous amount of energy producing nectar that it never uses. However, in the case of human evolution, natural selection could not even allow the sense of smell to be as keen as it once was, because human beings couldn’t afford to waste resources on a less-useful sense.

This, as I see it, is the reason evolution cannot be falsified. It simply has too many excuses built into it. With enough excuses, you can accommodate any amount of data. As I have mentioned previously, similarities among organisms are supposed to be evidence of common ancestry. However, there are many, many examples of similarities between species that evolution cannot accommodate as being linked by a common ancestor with such a trait. As a result, evolutionists call that “convergent evolution” – a case in which evolution “just happened” to come up with similar traits in two unrelated organisms. In other words, similarities between organisms are evidence of evolution when evolution can accommodate them, and they are simply the result of chance when evolution cannot accommodate them.

When a theory is so plastic that it can be molded to fit any data, it is no longer a scientific theory. That’s where evolution is today.

REFERENCES

1. Darwin, C, The Origin of Species, Penguin Classics, 1985, pp. 228-229 (quote also contained in this free online chapter)
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2. David Sadava, H. Craig Heller, David M. Hillis, May Berenbaum, Life: The Science of Biology, Macmillon, 2009, p. 810
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3. Kitcher, P., Abusing Science: The Case Against Creationism, MIT Press, 1982, pp. 73-74
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Comments

6 Responses to “Evolution and Falsification”
  1. mona says:

    Hi Jay- great article, I really enjoyed reading it. But I wonder if the reason why the common backyard dandelion produces nectar is still to be discovered? Maybe the dandelion has a very important use for it, but just not for pollination. I just find it hard to believe that it would spend energy making something that is completely useless to it. It doesn’t really make sense to me. But I can understand why humans have a worse sense of smell than apes- if we don’t need it then wouldn’t it be smarter not to have it?

  2. jlwile says:

    Hi Mona – Thanks for the comment! I agree with you that the smell issue makes a lot more sense than the dandelion issue. I can see why natural selection would favor genetic changes that reduced the resources put into a sense that is not so important. I can also see how a Creator would not design an organism that wastes energy on a heightened sense it doesn’t need.

    However, it is hard to understand why dandelions continue to produce nectar unless, as you say, there is some “hidden” need for them to produce nectar. As far as I know, however, no such need has been discovered. The one thing I can say is that unlike evolutionism, creationism doesn’t need to look at just one organism. Evolution is all about the organism surviving. However, creation is all about the Creator producing a working system. Could it be that the dandelion is a prolific source of nectar specifically because the Creator wanted to design something to support a large insect population? Thus, the nectar production is something that makes the ecosystem work, not something that makes the dandelion work. I am not saying that is the answer, but it is at least a possibility.

  3. mona says:

    Hi Jay,

    I agree- that could definitely be a possibility.

    How come evolution and creation have to be so separate? Couldn’t it be that our Creator created evolution as a way for our world to improve? I think He has created many other systems more complicated than evolution.

  4. jlwile says:

    Hi Mona,

    Evolution and creation don’t have to be separate at all. Francis Collin’s group, Biologos agrees with you. A succinct way of stating their position is, “God is the who, evolution is the how.” The problem I have with that position is the evidence. A succinct way of stating my position is, “If God created by evolution, He covered His tracks really well.” (I know, Josiah – I don’t really believe God would cover His tracks). So to me, the creation/evolution debate is much more a scientific debate than a religious one.

  5. mona says:

    Hi Jay,

    Surely though, we can not expect to have scientific evidence for everything. What about the “string theory”… there’s not much concrete evidence to that, but many physicists believe it to be true.

    Sorry for the late reply- my mom was here for a week so it was a bit hectic for me!

  6. jlwile says:

    Hi Mona. I hope you had a good time with your mom. You are absolutely right – there are many ideas for which there is little or no evidence. Belief in such ideas, then, becomes a matter of taste or hope. String theory, for example, is an elegant attempt to reconcile quantum mechanics and general relativity, which both seem to be right but are inconsistent with each other. This appeals to many physicists because they WANT quantum mechanics and general relativity to be reconciled. However, since there is really no evidence for or against string theory, if you choose to believe it because of taste or hope, you had better not believe it too strongly. You should recognize that since your belief is not based on evidence, it is likely to be wrong. That’s doesn’t mean you shouldn’t believe it. It just means you should not be too confident in your belief.

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