Thursday 29 May 2014

Macro and Micro Nonsense

I recently came across this video by a YouTube "vlogger" who goes by the name "God Rules".  In the video, he claims that "macro-evolution" is not science because there is no factual evidence for it. I had a bit of a debate with myself as to whether or not to respond; while I accept the overwhelming scientific consensus behind evolution by natural selection I don't tend to say much about it because biology is not really one of my areas of interest. I eventually decided, however, to comment on this for two reasons: First, a few days ago, I criticised the Atheist Community of Austin for letting Don Baker spew his rubbish about Christian history without pulling him up, it feels wrong for me, as a Christian, not to take fellow Christians to task in the same way. Second, the whole thing about "macro-evolution" pressed some buttons of mine in that, while I don't know much about biology, I do understand the importance of good definitions.

For those who may not be familiar, "macro" and "micro" evolution is a distinction invented by creationists to get around the obvious fact that at least some form of evolution happens. Evolution simply means change and change happens in the biological world: new breeds of dogs come into existence, animals adapt to different environments, change happens. The response of creationists to this is to admit that these undeniable examples of evolution happen but to label them "micro-evolution" and to declare that this is something totally different from "macro evolution" such as humans and other apes having evolved from a common ancestor.

When asked to define the actual difference, creationist fall, broadly, into two camps. In the first camp, fall those who define Micro evolution as "adaptation within a species." while macro evolution (which, they deny happening) would involve new species coming into being (what biologists call speciation.). This school have at least this to be said for them, they at least have the courage to take a clear position, to nail their colours to the mast.

This is, evidently, the school to which "God Rules" belongs. At about the five minute mark of his video he begins claiming that atheists don't understand science and simply accept, as scientific, anything which supports their existing beliefs. As an example of this, he cites macro-evolution, saying that atheists accept it as science, in spite of there being absolutely no evidence to support it. He says that micro-evolution is a science, explicitly says that micro-evolution is "adaptation within a species" and concedes that the fact support the conclusion that this happens. He then tells us that there are no facts or evidence to support the proposition that macro-evolution happens. That was it, a blank assertion; he made no effort to interact with or refute any of the claims of evidence.

Unfortunately, for God Rules, there is very detailed observed evidence for speciation you can read about here and, in more detail, here. Put simply, the claims of this school are wrong and are documented as such.

Note: The preceding paragraph was edited, from its original form, in light of comments made in the comment thread below.

The second school of creationists have learned from the mistake of the first school. They define macro-evolution as a change, not in species but in kind. Comfort acknowledges that change in species happens, indeed in his recent debate with Matt Dilahunty, he declared that "we all believe in" speciation. (It's at about the thirty-one minute mark if you want to listen for yourself.) So, as an aside, let me congratulate "God Rules", in denying speciation, you have actually taken a position so widely at odds with the evidence that even Ray Comfort acknowledges that your claim is untenable.

Comfort's position, however, while, in a sense, cleverer, is also, let's call a spade a spade here, dishonest and cowardly. This was well illustrated in this video in which Comfort is interviewed by his fellow creationist Todd Friel. Comfort says that "change of kinds" has not been proven. In a way, Comfort is right. Change of kinds can't really be proven because, to be proven, a proposition needs a clear definition and there is no clear definition of the term "kind." In their interview, Friel asks Comfort about the meaning of kind (the relevant part of the interview starts at about six minutes, ten seconds into the video). Comfort gives the example of dogs as a kind. He says that different breeds of dogs are different species but they are all dogs and thus all one kind. Even if this were true (and it isn't, if Comfort had bothered to do basic research he'd have discovered that all dog breeds are members, not merely of the same species but of the same sub-species: Canis Lupus Familiaris) an example is not a definition. Comfort goes on to claim that kind is a well defined scientific term. To support this claim he says that "we have a clear definition of the word kind from a biological website."

I assume anyone with any discernment can see the snake oil here but let me spell it out: Comfort claims to have "a clear definition" but doesn't bother to tell us what the definition is. He says it comes from "a biological website" but doesn't cite the name or address. For example, what does "a biological website" mean?

Normally, when polemicizing against someone, I presume that that someone is arguing in good faith. In light of the above, I don't think Comfort can be extended that presumption. He is arguing dishonestly and deserves to be called out.

P.S. As a brief aside, if Comfort is actually saying that the domestic dog is a kind of animal, then his claim that animals reproduce only after their own kinds is easily refuted: the domestic dog (Canis Lupus Familiaris) can interbreed with the Eurasian Grey Wolf (Canis Lupus Lupus)

4 comments:

  1. Great post, Jason. A relatively tangential matter I'd like to pull up you on, though:

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  2. I was surprised by the comment about speciation being observed in the lab (having studied evolutionary biology up to PhD level). So I looked up the article you linked to, & read the wikipedia extract there. A few caveats:
    The type of reproductive isolation described in the extract is not sufficient to have speciation. It is accurate to say that this experiment replicated divergent mating choice that could ultimately lead to speciation, but they have not produced two separate species (yet). Speciation really requires the kind of reproductive isolation where two groups of organisms cannot produce fertile offspring if they do somehow mate. This hasn't occured with this experiment & even the diagram shows two members of the different populations mating - presumably to show that while they would prefer to mate within their own population, this preference isn't even exclusive let alone incapable of producing fertile offspring.

    I believe in/accept the scientific evidence for "macroevolution" and "microevolution", of course, but the case of Comfort, etc., is strengthened (a little) by the fact that real speciation is infuriatingly difficult to observe in real time. For offspring to no longer be fertile or viable, differences at the chromosomal level need to accumulate & then become fixed in each population (e.g. reversals of bits of chromosomes, merges of chromosomes, duplications, large deletions, etc.). You may need considerable numbers of these before resulting in non-viable or infertile offspring. In theory, this might happen quickly if mutations happened to affect reproductive organs, so that a hybrid individual had reproductive organs that simply didn't work. But the chances of such mutations accumulating & fixing quickly in populations just around genes affecting this part of the body would be pretty remote.

    As far as can be told currently, for the kind of genetic & phenotypic change to accumulate before speciation can be regarded has having happened takes a great number of generations. Despite considerable searching, it would appear rare for this to not include a great number of generations of geographic separation of two populations to start with. New mutations need to occur, then increase in frequency, then fix within a population, either by being highly favoured by natural selection or more often through founder effects & population bottlenecks. Reproductively segregating phenotypes (such as the flies' mating preferences in your example) might arise & fix in the meantime, and may enhance the blocking of gene flow between the two speciating populations, but they are not sufficient or even necessary for speciation to occur.

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  3. Krafty, Thanks for the comments. Obviously, as I said, I'm not a biologist, which is why I tend not to write about this stuff so often.

    That said, I note the Wikipedia article I linked mentions two different experiments with fruit-flies, the Dodd experiment and the Rice/Salt experiment. What you say about the Dodd experiment is fairly obviously true, it produced two populations with a mating preference, which, as you say, is not speciation. However, the Rice/ Salt experiment, seems to have produced (after 35 generations, I might add) flies not only with a preference to breed with their own population but flies that did not, in fact, breed with one another.

    I'll repeat myself again, I make no claim to any kind of expertise in this area, but I did a reasonable amount of reading before posting this and I've done a bit more since reading your comment and there seems to be a reasonable amount of literature supporting the idea that experiments like the Rice/Salt experiment do support speciation.

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  4. That said, I'll edit the relevant paragraph above in light of your comments.

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