Darwin’s Doubt – Chapter 1 – Part 5
Here’s where I start to have serious difficulty with Meyer. You see, we both have bachelor degrees in the same field, Earth Science. Now, I don’t know how Whitworth College (hint: it’s a Christian college) teaches Earth science, but I seem to have been taught completely different than Meyer. Also considering that Meyer actually worked as geophysicist in an actual company, he ought to know better.
Anyway, this section, entitled “Dating by Discontinuity” is about geology. Specifically about how we can “date” certain events using basic geological principles and fossils. Meyer is very innovative in crafting a deception. And make no mistake, it is a deception.
Meyer gets the first bit right. Modern geology was effectively being used before Darwin’s work. William Smith published a geological map of England in 1815. This map was actually useful for things like digging canals and the like. Charles Lyell published his Principles of Geology in 1830. This book, as we all know, is one that Charles Darwin read and gave him a lot of ideas that he then applied to living things.
Principles basically formalized the idea of uniformitarianism. That is, the Earth’s geologic structures are mainly formed by slow processes rather than a catastrophic single event (say, for example, a global flood of Biblical proportions). Uniformitarianism consists of 4 basic rules:
- Uniformity of law – the laws of nature are constant across time and space.
- Uniformity of methodology – the appropriate hypotheses for explaining the geological past are those with analogy today.
- Uniformity of kind – past and present causes are all of the same kind, have the same energy, and produce the same effects.
- Uniformity of degree – geological circumstances have remained the same over time.
The end result of these rules is that certain things in the geologic column are expected. For example, we expect that a layer of rock that is on top of another layer of rock to younger. We expect that a fault through both those layers is younger still and an igneous dike through both layers and the fault is the youngest.
There are cases where these things are not true, but they are rare and it is usually quite obvious that something unusual is going on. One example would be a fold that is so extreme the layers of rock form a shape like a U lying on its side. Imagine taking three thin pancakes of playdough of three different colors and laying the on top of each other. Now fold grab one edge and fold it over to meet the opposite edge. You suddenly have older rock on top of younger rock. Like said though, this is generally very obvious in the geologic record.
For example, this image taken by Professor Ian Alsop of the University of Aberdeen.
Now we know which rock layers are older and which are younger. But there’s a problem. The rock layers aren’t the same everywhere. There is no single place on Earth that has a complete geological column of rock… from the present to the beginning of the Earth.
In theory, we should be able to map columns of rock that overlap and build an entire picture of the geologic column. In theory… Honestly, limestone pretty much looks like limestone all over the world. Granite looks like granite and shale looks like shale. We would need a way to make sure that we are looking at the same layers even if they are two different parts of England (or Europe or the world). Hmmm…. what kind of things would be in the rocks and could possibly have a wide distribution and yet only be in those particular rocks layers? Anyone? Bueller?
They are called “index fossils” and William Smith was well aware of them in 1815.
The plan is simple. Ocean organisms can be widespread and are much more likely to be preserved in sedimentary rock. So, if we determine that a certain group of fossils (say Trilobites) are very widespread and change over time (becoming more complex). Then we can see the relative dates of certain layers based on the presence of certain trilobite types.
One very important caveat and something that is massively misunderstood (or ignored) by modern creationists is that this is relative dating of rock layers for the purpose of stratigraphy (that is the science of rock layers). This is not a circular argument in which we say that fossils are old because they are in old rocks and we know that the rocks are old because it has those fossils in it. Anyone who says this is either someone who is lying or someone who has been lied to.
OK, that’s your geological history lesson for the day. Keep in mind that these 300 words or so took me three years of classes.
Anyway, like all science (and reality) things change as we get new information. Uniformitarianism isn’t perfect. Just like Darwin’s ideas have been modified over time, so have Lyell’s ideas on geology. We do know that there are catastrophic events that can be world wide (K/T extinction anyone?).
Meyer says that Stephen J. Gould was something of an opponent of uniformitarianism (and I am never going to use that word again after typing it out many times). Meyer takes the following quote from Gould’s Wonderful Life: The Burgess Shale and the Nature of History (this link to the digital book and go to page 54). The part that I have bolded is what Meyer quotes in Darwin’s Doubt (location 424 in the kindle edition).
When such blandishments fail, I always say, try an honest intellectual argument: if these names [ed: the geologic time periods] were arbitrary divisions in a smooth continuum of events unfolding through times, I would have some sympathy for the opposition – for then we might take the history of modern multicellular life, about 600 million years, and divide this time into even and arbitrary units easily remembered as 1-12 or A-L, at 50 million years per unit.
But the earth scorns our simplifications, and becomes much more interesting in its derision. The history of life is not a continuum of development, but a record of mass extinction and subsequent diversification. The geological time scale maps this history, for fossils provide or chief criterion in fixing the temporal order of rocks. The divisions of the time scale are set at these major punctuations because extinctions and rapid diversification leave such clear signatures in the fossil record. Hence, the time scale is not a devil’s ploy for torturing students, but a chronicle of key moments in life’s history. By memorizing those infernal names, you learn the major episodes of earthly time. I make no apologies for the central importance of such knowledge.
Meyer then asks the question:
How could he [Darwin] reconcile his theory of gradual evolution with a fossil record so discontinuous that it had given rise to the names of the major distinct periods of geological times, particularly when the first animal forms seemed to spring into existence during the Cambrian as if from nowhere?
Yes, there are discontinuities in the geologic history of Earth. That’s why index fossil are so important.
Yes, major extinction events form the basis for some of the boundaries in the geologic time scale. For example, the previously mentioned K/T extinction was the end of the reign of dinosaurs and the beginning of the rise of mammals (and birds).
Again, this a rather ingenious ploy to discredit Darwin. Again, for the record, who cares. Anyone who says that Darwin is all-mighty and cannot be countered is an idiot. Look at who Meyer is quoting here. Stephen “Punctuated Equilibria” Gould who basically said that species tend to remain static over long periods of time, then something happens and you have mass diversification. He basically said that Darwin was wrong and here’s how life really diversifies. Of course, nothing Gould said (in spite of what creationists claim) discredits natural selection, random mutation, and all that either. These concepts are not, as creationists would have us believe, black and white. It’s not “if uniformitarianism (dammit), then not catastrophism”. It’s both, maybe not in equal measure, but both situations have applied to Earth’s past. It’s not gradual evolution OR punctuated equilibria. Gould never suggested that populations don’t evolve during those times of equilibria.
Creationists are trying to drive a wedge (get it, a wedge? nevermind) in the sciences. Anything that casts doubt on anything in science is good for them (or so they think).
But, (according to Meyer’s thinking) if Darwin can’t explain away a potential issue that appeared nearly 120 years after he died, then the entire theory of evolution is in serious trouble. That’s plain dumb.
Yes the fossil record is also discontinuous, but again, so what. Here, Meyer seems to require that Darwin (who BTW was not a paleontologist) find every single organism in every single lineage from the beginning of time to the present in order to support his theory.
Really, Dr. Meyer, do you really want to go there? What if I require that of you? What if I require that you provide a complete lineage of yourself from present to Adam and Eve… and if you can’t, then you therefore weren’t born. Is that really the requirement that you have for evolution? If so, then why do you have different requirements for your own preferred notions?
If there’s any interest, I’ll do a whole post on stratigraphy and how we use rock layers, index fossils, and radiometric dating to get some really good ideas of the ages of rock layers. That is absolute ages, not relative ages.
P.S. I’d like to extend a “Thank You” to Panda’s Thumb for promoting this series. I’m a regular there and I’m sure that they will be asking when the next installment is. It helps to have both encouragement and the occasional kick in the ass. Also, if I make a mistake, they will catch it.
When I was in college, the joke in the geology department was to ask a mathematician, a statistician and a geophysicist what 1+2 equaled. The math guy would say “3″. The statistician would say”3 plus or minus 0.000001″ and the geophysicist would say “What do you want it to be?” Having known a few (and having to teach a class in historical geology because the geophysicist who was supposed to teach it didn’t believe in an Earth older than 10,000 years… I have a low opinion of geophysicists..