Why I’m Still a Young-Earth Creationist, Even Though It’s Getting Increasingly Lonely over Here
Having considered mutation and natural selection, I turn now to the third leg of the evolutionary stool: the time scales that are necessary for all of this naturally directed change to occur. Evolution needs billions of years, and that’s why we have old-earth and young-earth views.
So is there evidence for the geologic ages, or not?
Well, that’s an interesting question.
There are lots of geochronometers, or ways to calculate the age of the earth. I remember seeing a documentary years ago narrated by Donald Johanson, the paleontologist who discovered Lucy. He talked briefly about the age of the earth and cited 3 different geochronometers, completely unrelated to one another, that triangulated nicely on about 4.5 billion years. I remember thinking, “Wow. That’s really impressive!” So I started reading. And I found out that the geochronometers are all over the place. Lots of them point to 4.5 billion years, yes, but others point to widely differing ages—with a good many well within the range called for by a straightforward reading of Genesis.
Two questions, then. First, why is there so much variation? And second, which ones are you going to believe?
With that much variation, they can’t all be right. So what’s up? A look at a single method might help answer the question. As you know, there are lots of elements and compounds in sea water—most obviously salt, but lots of other stuff too. You can pick one of those—let’s say salt—and measure its concentration in sea water. Then you can try to calculate how much saltier the sea is getting every year—or you can just log your measurements over a period of several years—and you can run that number back to calculate how many years ago the sea would have had no salt in it. That gives you a presumed date for the beginning of the ocean, which is not necessarily the same as the age of the earth, but at least it’ll tell you whether you’re dealing with thousands or millions or billions of years.
[As usual, there’s more to this than what I’ve mentioned here. Salt settles out of sea water in sediment, and there are other variables as well. The method attempts to take all of this into account.]
Well, it turns out that when you run those numbers for different substances—salt, magnesium, calcium, whatever—you get different dates, sometimes widely varying dates. Why?
I think the answer is obvious. There’s an assumption behind the method. When you extrapolate the rate of increasing concentration back into previous years, you’re assuming that the rate was essentially constant over time. That seems to be a reasonable assumption, but it’s an assumption nonetheless; it’s uniformitarianism, which underlies pretty much all of evolutionary thinking.
But imagine another scenario. What would an unusual year—say, a year with a significant flood, even a global one—do to the numbers?
So our calculations are hostage to annual deviations in runoff to the oceans. And the very fact that our numbers differ from substance to substance tells us that the deposition has not been uniform. Our assumption is wrong, and our results are therefore invalid.
So we have dates, “measured” by geochronometers, that are all over the place.
Which ones do we pick?
Ah, there’s the rub. Our choices will be driven by our assumptions. If you’re Donald Johanson, and you’re confident that the earth is 4.5 billion years old, you’re going to select those indicators as examples of how science is done. After all, the ones that take us below 10,000 years can’t possibly be right. They’re statistical outliers. Obviously.
That’s called slanted selection of evidence, and like assuming your conclusion, it’ll get you an F on your freshman research paper.
(Now, this is a sword that cuts both ways. I’m strongly tempted to listen to just the geochronometers that indicate a young earth; I’ve even linked to several above. I need to do the best I can with the data myself, not letting my bias cloud my openness to hard facts.)
But my point is that the geochronometers don’t tell a single story, because we can demonstrate that a great many of them are based on illegitimate assumptions. So why do we insist that only one story can be told, and that the tellers of other stories are mythematicians? And where is the robustness in the evidence that seeks to turn me from the Scripture?
Next time, we’ll touch on a significant theological concern.