I’ve mentioned on the blog that my dad is a Southern Baptist pastor. I attend church with the rest of the family to keep the peace, but I sit in the foyer and read books or play on the playground with my nephew. Once in awhile I’ll overhear something that upsets me, roll my eyes and go back to reading. I decided this morning I’m going to start paying attention so that I can write about what is said. It will give non-religious people a glimpse inside and evangelical church and give me a chance to offer a rebuttal (or just make fun of the silliness).
This morning my dad’s sermon was entirely devoted to disproving evolution. I was homeschooled, so I’ve heard it all before, but I took notes anyway. He is a young-earth creationist. His main assault focused on the fossil record, unreliable dating methods and Mount Saint Helens.
He opened by explaining that creation is the foundation of Christianity. If creation didn’t happen then there was no need for God. If the Genesis account cannot be taken literally then Adam and Eve didn’t exist, original sin doesn’t exist and every other biblical claim begins to break down.
So far, we are in complete agreement.
Several years ago, his friend Dr. G. Thomas Sharp visited our church to do a series of seminars on creationism. Dr. Sharp is a fairly prominent creationist, although he is much less well known than Ken Ham. Dr. Sharp started the Creation Truth Foundation and wrote a set of books titled Science According to Moses. Between seminars, they visited a fossil shop in Albuquerque, where Dr. Sharp bought my brother and me a trilobite fossil. I still have the fossil – it’s one of my favorite things. The fossil was labeled as being about 400 million years old. Dr. Sharp asked the man behind the counter how they knew it was that old. He answered, saying it was found in geological strata from the Devonian Period. So Dr. Sharp asked him how he knew the geological strata where the trilobite was found was 400 million years old. The man answered, “because we found trilobites there”.
My dad has used this as an example of circular reasoning ever since. He says that scientists don’t have a clue what they’re talking about. They just make up arbitrary dates and stick to their false stories.
Perhaps this particular fossil shop employee was not a geologist. Maybe he was just a cashier or a fossil enthusiast. Just because he didn’t know the science behind dating methods, doesn’t mean the dating methods are flawed. I’m not a scientist, I’m just a homeschooler playing catch-up by reading Richard Dawkins and Jerry Coyne books. However, I’m pretty good at using Google, so I did some research this afternoon. Talk Origins references this exact argument here: http://www.talkorigins.org/indexcc/CC/CC310.html
How do we know fossils from the Devonian Period are between 359-416 million years old? For that matter, how do we know the age of any geological strata is correct? That involves some detective work on the part of geologists. To do this, geologists have two basic approaches; relative age dating and absolute age dating. Relative age dating involves a common sense assumption called the Rule of Superposition. This basically means that in a sequence of sedimentary rock layers, the newer rock layers will be on top of older ones. For example, we can know that Cambrian strata are older than Permian because Permian is much closer to the surface. This method tells us which strata are older, but we still need a method to determine how old each one is. That’s where the absolute dating method comes in.
One of the primary ways to determine absolute age is through radiometric dating. I won’t get too technical, but here are the basics: the radioactive isotopes of some elements decay at a known, fixed rate. The rate of decay is called half-life. Half-life is the amount of time it takes for half of an isotope to decay into a daughter product. Geologists can measure the ratio of remaining parent isotope to the amount of daughter element to determine how long the rock has been there. While there are some exceptions, sedimentary rock doesn’t contain radioactive elements, for instance, geologists have some other dating options. If they can find volcanic ash sandwiched between sedimentary layers, they can use radiometric techniques on the ash.
Some creationists will argue that these dating methods are inaccurate. In most instances, I’ve found that their evidence for inaccuracy point to unqualified people attempting to use the dating method in an incorrect way. Each radioactive isotope works best particular applications. Because carbon-14 has a relatively short half-life, it can be used to measure in the tens of thousand of years range. Potassium-argon, on the other hand, can be used for dating in the millions and billions of years range. All dating methods have a known margin of error. The margin of error is reduced by using multiple dating methods which cross-check each other. For more on radiometric dating: http://geomaps.wr.usgs.gov/parks/gtime/ageofearth.html and http://answersinscience.org/RadiometricDating-Woolf.htm and http://www.talkorigins.org/faqs/dating.html
By contrast, the young-earth creationists determine the age of the earth by adding together the ages of people found in biblical genealogies, accounting for overlap in their lifetimes. That’s it. No evidence, just a book that claims some people lived to be over 900 years old. How could evolution possibly stand up to that?
Next, my dad pointed to his evolution killer. The evidence that would forever eradicate the veracity of evolution, geological rock strata and the fossil record. The eruption of Mount Saint Helens in 1980. This is a lesser known creationist argument, but I’ve heard it addressed by both Dr. Sharp and Ken Ham in the past. They say that geologists claim fossilization take millions of years, but that can’t be true because the eruption of Mount Saint Helens formed fossils virtually overnight.
This creationist argument falls is based on a false assumption of how fossils form. Once you examine the actual science, it falls apart rather quickly. Contrary to creationist claims, fossils must be formed quickly.
Here’s an excerpt from FossilMuseum.net explaining the process:
The remains of an organism that survive natural biological and physical processes must then become quickly buried by sediments. The probability for an organism to become fossilized increases if it already lives in the sediment , and those on the sea floor are more readily fossilized than those floating or swimming above it. Catastrophic burial with a rapid influx of sediment is necessary to preserve delicate complete animals such as crinoids or starfish.
Upon further inspection of Mount Saint Helens, you find that it wasn’t animal fossils that were formed. It was so-called polystrate fossils (not a geological term), which are technically petrified trees. Creationists use the word polystrate to describe petrified trees that intersect several rock beds. The existence of polystrate trees has never presented a stumbling block for geologists. You can read more on the subject here: http://www.talkorigins.org/faqs/polystrate/polystrate_trees.html
Other creationist arguments stemming from Mount Saint Helens are that the eruption rapidly laid down layers of rock strata, but in a very short amount of time; that rapid erosion along the Toutle River formed a canyon quickly, showing that the Grand Canyon could have also been formed quickly; and that the eruption formed coal beds in Spirit Lake. I won’t go into detail on these arguments since this post is already so long that most people won’t read it. You can view responses to all three claims by clicking the links above. These arguments are straw men, quickly knocked down by actual scientists doing actual science.
All of the Mount Saint Helens talk leads up to the idea that millions of years are not needed to form the strata and fossils. Rather, all you need are quick catastrophes to do take care of the job. Perhaps, this could’ve happened because of one global catastrophe, such as Noah’s flood? Well, that’s their idea, but it doesn’t hold up to serious science. There are so many holes in the theory that it isn’t necessary to list them all here. Everything discussed above is just the tip of the iceberg that sunk Noah’s Ark long ago. Creationists just have a lot of catching up to do.
Check out the science section of my recommended reading lists for several fantastic books on the subject of evolution.