Not So Polite Dinner Conversation – Part 9, the second half of #19, limestone, coelacanths and circular reasoning

Part 2 of the entry for #19  We’re at the penultimate post for addressing all of this nonsense! 

Precambrian rabbit
Precambrian rabbit

Next are mentions of limestones, living fossils and polystrate fossils.  Oh and a quote from Dawkins, whom creationists are sure that all atheists worship.  The quote is “”Creationists are fond of saying that there are very few fossils in the Precambrian, but why would there be?” asks Dawkins. “However, if there was a single hippo or rabbit in the Precambrian, that would completely blow evolution out of the water. None have ever been found.”  This is a paraphrase of the Precambrian rabbit quote from Haldane.  The idea is that one out of place fossil would destroy evolutionary theory.  And as we can see in the link to the rabbit quote, it isn’t necessarily true.  It would surely show a major problem with it, the thought that the Precambrian is the era of some of the simplest creatures, but all of the current evidence for evolution wouldn’t be shown wrong.  We still have adaptation to environment still demonstrated in the fossil record and still going on. 

Despite what it might look like in your driveway or on a gravel road, limestones are very diverse and not all come from fossils. They are also not often pure calcium carbonate.  One of my early tasks as a geologist was to identify a bunch of them.  Here in central PA, we have lots of limestones and we were doing a lot of drilling into them when setting wells to monitor pollution.  The limestones could be identified by their chemical make-up and that required some of the nastiest chemicals you can buy, including some wickedly toxic mercury compounds, hydrogen cyanide, etc. By that we can know the environment where they formed. We can date them, by radiometric dating, etc.  Since they do not always have fossils, they are not always dated by fossils. Other ways to date are date the rocks above and below and the ones between are between the others in ages, which can happen with limestone, when you might get a coal layer showing up or a volcanic ash deposit that can be dated easier than the limestone. 

One other thing that limestones do to creationist claims is make them ridiculous since the time to build up foraminifera enough to make a layer is far more than their silly 6000+ year time line.  And when simply chemically precipitated out, well, we get poached Noah again. Continue reading “Not So Polite Dinner Conversation – Part 9, the second half of #19, limestone, coelacanths and circular reasoning”

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