Sunday, November 26, 2017

Review: The Blind Watchmaker by Richard Dawkins, part 2

There are a couple of places in this book where Dawkins addresses intelligent design. He addresses it on page 141 in the context of the origin of life, then again on page 316-317 in the context of evolution. He says basically the same thing he said in The God Delusion. Essentially, he raises the “Who designed the designer?” argument. Here is what he said:

So, cumulative selection can manufacture complexity while single-step selection cannot. But cumulative selection cannot work unless there is some minimal machinery of replication and replicator power, and the only machinery of replication that we know seems too complicated to have come into existence by means of anything less than many generations of cumulative selection! Some people see this as a fundamental flaw in the whole theory of the blind watchmaker. They see it as the ultimate proof that there must originally have been a designer, not a blind watchmaker but a far-sighted supernatural watchmaker. Maybe, it is argued, the Creator does not control the day-to-day succession of evolutionary events; maybe he did not frame the tiger and the lamb, maybe he did not make a tree, but he did set up the original machinery of replication and replicator power, the original machinery of DNA and protein that made cumulative selection, and hence all of evolution, possible.

This is a transparently feeble argument, indeed it is obviously self-defeating. Organized complexity is the thing we are having difficulty in explaining. Once we are allowed simply to postulate organized complexity, if only the organized complexity of the DNA/protein replicating engine, it is relatively easy to invoke it as a generator of yet more organized complexity. That, indeed, is what most of this book is about. But of course any God capable of intelligently designing something as complex as the DNA/protein replicating machine must have been at least as complex and organized as that machine itself. Far more so if we suppose him additionally capable of such advanced functions as listening to prayers and forgiving sins. To explain the origin of the DNA/protein machine by invoking a supernatural Designer is to explain precisely nothing, for it leaves unexplained the origin of the Designer. You have to say something like ‘God was always there’, and if you allow yourself that kind of lazy way out, you might as well just say ‘DNA was always there’, or ‘Life was always there’, and be done with it. (p. 141)
And again:
We cannot disprove beliefs like these, especially if it is assumed that God took care that his interventions always closely mimicked what would be expected from evolution by natural selection. All that we can say about such beliefs is, firstly, that they are superfluous and, secondly, that they assume the existence of the main thing we want to explain, namely organized complexity. The one thing that makes evolution such a neat theory is that it explains how organized complexity can arise out of primeval simplicity.

If we want to postulate a deity capable of engineering all the organized complexity in the world, either instantaneously or by guiding evolution, that deity must already have been vastly more complex in the first place. The creationist, whether a naïve Bible-thumper or an educated bishop, simply postulates an already existing being of prodigious intelligence and complexity. If we are going to allow ourselves the luxury of postulating organized complexity without offering an explanation, we might as well make a job of it and simply postulate the existence of life as we know it! In short, divine creation, whether instantaneous or in the form of guided evolution, joins the list of other theories we have considered in this chapter. All give some superficial appearance of being alternatives to Darwinism, whose merits might be tested by an appeal to evidence. All turn out, on closer inspection, not to be rivals of Darwinism at all. The theory of evolution by cumulative natural selection is the only theory we know of that is in principle capable of explaining the existence of organized complexity. Even if the evidence did not favour it, it would still be the best theory available! In fact the evidence does favour it. But that is another story. (p. 316-317)
I think Dawkins would have a point if what we were trying to explain was the origin of intelligence. To say that intelligence came about because some other intelligence created it is not to explain the origin of intelligence at all because it leaves the intelligent creator unexplained. As long as you’ve got an unexplained intelligence, you haven’t explained the origin of intelligence per se.

That appears to be a perfect parallel to what Dawkins is trying to argue except that instead of intelligence, he says we are trying to explain the origin of organized complexity. If we postulate an organized complex entity, like God, to explain organized complexity, then we haven’t really explained organized complexity at all since we’ve left God unexplained.

Dawkins’ argument commits the fallacy of equivocation. He says that for God to be able to design the DNA/protein replicating machine, God would have to be at least as complex and organized as the machine itself. Maybe one could argue that God would have to be complex and organized in some sense, but surely God would not have to be complex and organized in the same sense that the DNA/protein replicating machine is complex and organized.

Dawkins goes to great lengths on pages 6 through 9 to explain what he means by complexity. He says that a complex entity would have to be heterogeneous, meaning it “has many parts, these parts being of more than one kind.” Then he says the parts must be “arranged in a way that it is unlikely to have arisen by chance alone.” But since any arrangement of parts can be equally unlikely with hindsight, the arrangement must be something that can be “specified in advance.” What he appears to mean is that the parts must be arranged in such a way that the entity is “good for something,” or that it can “succeed in making a living of some sort,” such as “flying, swimming, swinging through the trees, and so on.” To summarize, Dawkins says:

This has been a long, drawn-out argument, and it is time to remind ourselves of how we got into it in the first place. We were looking for a precise way to express what we mean when we refer to something as complicated. We were trying to put a finger on what it is that humans and moles and earthworms and airliners and watches have in common with each other, but not with blancmange, or Mont Blanc, or the moon. The answer we have arrived at is that complicated things have some quality, specifiable in advance, that is highly unlikely to have been acquired by random chance alone. In the case of living things, the quality that is specified in advance is, in some sense, ‘proficiency’; either proficiency in a particular ability such as flying, as an aero-engineer might admire it; or proficiency in something more general, such as the ability to stave off death, or the ability to propagate genes in reproduction. (p. 9)
The reason I accuse Dawkins of equivocation is because God is obviously not complex in the same sense that biological organisms (or airliners and watches) are complex. God may be complex in the sense that he has various attributes and a creative mind, but he’s not complex in the sense that he has various physical parts that are arranged in an unlikely way that results in some function that allows him to make a living and reproduce. Clearly, when we say a biological organism, or an airplane, is complex, we don’t mean the same thing as we might mean if we said God is complex.

Consider one example of supposed intelligent design—information in DNA. Stephen Meyers argued in Signature in the Cell that information always comes from a mind, and since DNA contains information, that information came from a mind. That same argument could not apply to God since God wouldn’t have anything like DNA. He wouldn’t have anything like a digital code written into his parts that codes for proteins. So this intelligent design argument would be immune to Dawkins’ criticism. The best Dawkins could say in response to this argument is that an intelligent designer is unnecessary since information can arise without a designer, but he couldn’t claim that information in DNA hadn’t been explained since the intelligence behind it hadn’t been explained. That would be like saying that programmers don’t explain computer programs since it leaves programmers unexplained or that authors don’t explain books since it leaves authors unexplained.

Neither natural selection nor intelligent design are meant to explain the absolute origin of complexity in general. Both have a more narrow focus. They are trying to explain biological complexity in physical living organisms. In that case, it’s perfectly reasonable to explain complexity in biological organisms by postulating an entity that is not a biological organism, even if that entity is complex in some sense. If I appeal to one complex entity in order to explain another complex entity, I may not have explained the origin of complexity in general, but I have explained the origin of a particular manifestation of complexity.

The difference between God and biological organisms is particularly revealing in how Dawkins responds to the claim that “God was always there.” He says that if we’re going to allow ourselves the luxury of postulating an already existing complex entity like God, you might as well just say, “DNA was always there,” or “Life was always there.” But it is precisely because we already know DNA and biological life were not always there that gives rise to the need to explain them by postulating something that was always there.

As long as anything contingent exists, something necessary must exist. Each contingent thing is explained either by some other contingent thing or by some necessary thing. Necessary things do not require other things to explain them. They exist because they are necessary, and their necessity is a sufficient explanation for their existence. So always-existing things can be invoked to explain contingent things. All parties agree that DNA and protein are contingent things. It is because they are contingent things that we cannot simply postulate them the same way we can postulate an always-existing Designer. Once we trace all contingent things back to some necessary thing or things, our explanation is complete.

And now my review of The Blind Watchmaker is complete. I know I sound mostly negative in this second part, but I was only criticizing a small part of Dawkins’ book. The book as a whole is fantastic, and I recommend it. I would give it four and a half stars.

Review: The Blind Watchmaker by Richard Dawkins, part 1

I just finished reading The Blind Watchmaker by Richard Dawkins. Over all, I would say this is an excellent book. It wasn’t exactly what I expected, though. The subtitle reads, “Why the evidence of evolution reveals a universe without design.” I expected Dawkins to go into some detail about the hard evidence—fossils, geology, geography, genes, heredity, homology, etc. But really, most of the book was theoretical and speculative. For the most part, he showed how evolution could happen without showing that it did.

That’s not to say he didn’t discuss the hard evidence. He did. It just wasn’t the main focus of the book. Concerning the hard evidence, there was one part of the book I found to be especially compelling. It was chapter 10: “The one true tree of life.” More specifically, it was pages 270—276. And even more specifically, it was pages 274—275. I am probably going to butcher this explanation.

Okay, so there are a lot of genes in our DNA that code for proteins, and those same genes and proteins can be found in various species. However, there will be neutral differences, meaning there’ll be differences in the code that don’t affection the shape or function of the protein. That means they are invisible to natural selection. According to Dawkins, a given protein will change at the same rate regardless of what species that protein is found in. And, he says, we can know what that rate of change is, which allows us to know how long ago two species branched off from each other, i.e. how long ago their common ancestor lived. Unfortunately, Dawkins doesn’t tell us how we know about the mutation rate (unless it’s somewhere else in the book and I missed it).

Let’s suppose we have five different species, and we want to see how they are related to each other on a family tree. Well, we can look at the same protein in all five species, and by comparing them, we can tell how they are related to each other by how they differ. It’s a lot like textual criticism. You can tell that a text belongs to the Alexandrian text type or the Byzantine text type by looking at the differences of a given text. Supposedly, we can even tell how long ago each of them branched off from the others—the species, not the texts.

However, it’s always possible that a protein in two different species will change in the same way. It’s just a big coincidence when they do, and it apparently doesn’t happen very much. If it does happen, then looking at the one protein in each of the species will give you the wrong idea about how they are related and when their common ancestor lived.

But there’s a solution to that problem, and this is really the part that I found compelling. You don’t have to just rely on one protein to figure out a family tree. You can look at multiple proteins. The crazy thing is, when you look at multiple proteins, they will all tell the same story. You might get one that tells a slightly different story in case there was some huge coincidence in which the same protein in two different species mutated in exactly the same way. But that false reading can be recognized and corrected since every other protein tells the same story. It’s unlikely that one protein in two species would mutate in the same way, which is why we call it a coincidence, but it’s a whole lot more unlikely that two different proteins shared by two different species would both mutate in exactly the same way. These various proteins not only agree with each other in how the various species are related to each other, but they even agree on how long ago the different species branched off from each other.

I find this to be very compelling evidence for common ancestry. The fact that different species share the same protein, even if slightly modified, is flimsy evidence for a common ancestor. You could only arrive at that conclusion if you already assumed they had a common ancestor, and you were just trying to figure out how closely related they are. But if various species were not actually related by common ancestors, and you analyzed multiple proteins they had in common on the hypothesis that they were related, it seems highly unlikely to me that they would all give the same results. While you might dismiss one protein that points to a certain relationship, it’s hard to dismiss multiple proteins when they all give the same relationship and age of divergence.

It won’t do to say that a designer would, of course, use the same code in various species. Surely he would, but remember that we are talking about neutral differences in these proteins. They are differences that don’t affect the shape or function of the proteins. So there is no reason for them to be different on the hypothesis that a designer created them directly except that it doesn’t matter and they might as well be. But if it doesn’t matter, then we should expect the differences to be arbitrary, and if the differences are arbitrary, then we should not expect multiple proteins shared by different species to all agree on how those species would be related if they shared common ancestors.

That is not to say a designer is unlikely to have been involved. From what I understand, there are different theories in intelligent design about when, where, and how the designer got involved. Maybe he designed and assembled the first cell, and it took off from there. Maybe he interjects new information into DNA on rare occasions, like when he wants to add a brand new gene or disable one. Or maybe he manipulates the environment in such a way as to determine natural selection. All of those, it seems to me, would be consistent with the evidence I’ve been discussing. So a designer is not inconsistent with common descent. I only mean to say that Dawkins gave what seems to me to be a very compelling argument for common descent that suggests to me that each species was not a special creation that God made from scratch.

In part 2, I’ll talk about some problems I had with the book.