A Quick Case of Circular Reasoning in Evolutionary Biology


I’d like to demonstrate how human evolutionary theorists use false circular reasoning with regard to the geologic column.

Here is an example from page 351 of Prentice Hall’s Biology: Exploring Life 2006 high school textbook. After addressing how radiometric dating can show the age of rocks without addressing any of its flaws (the set-up), it shows this diagram:

351 of Prentice Hall's Biology: Exploring Life 2006

The problem with using the geologic column and index fossils for dating is that the fossils are dated by the rock layers they are in and the rock layers are dated by the fossils that are in them.

Notice the questions, this one in particular:

If radiometric dating identifies the rock in layer C as 425 million years old, what can you infer about the age of the fossils in layer C? In layers B and D? Explain.

The student answers, “Well, that’s easy! It’s 425 million years old.” Now, what do you think this student’s answer will be after being shown a fossil and asked how old the rock is in which the fossil was found? The date of the rock will be assumed because of the fossil that was found in it. The student then goes home to spread this news to his younger brothers and sisters when they drag out their dinosaur action-figure playset later that evening. This is misleading circular reasoning based upon the definition of what is called an Index Fossil which in turn is based upon Charles Lyell’s theory of uniformitarianism.

Index Fossil any animal or plant preserved in the rock record of the Earth that is characteristic of a particular span of geologic time or environment. A useful index fossil must be distinctive or easily recognizable, abundant, and have a wide geographic distribution and a short range through time. Index fossils are the basis for defining boundaries in the geologic time scale and for the correlation of strata.

Pay careful attention to the conclusion of the definition:

Index fossils are the basis for defining boundaries in the geologic time scale and for the correlation of strata.

Do you see the problem? The problem with using the geologic column and index fossils for dating is that the fossils are dated by the rock layers they are in and the rock layers are dated by the fossils that are in them. This is a classic case of false circular reasoning.

Uniformitarianism – a geological doctrine. It states that current geologic processes, occurring at the same rates observed today, in the same manner, account for all of Earth’s geological features. Thus, it assumes that geological processes are essentially unchanged today from those of the unobservable past, and that there have been no cataclysmic events in earth’s history. As present processes are thought to explain all past events, the Uniformitarian slogan is, “the present is the key to the past.”

If uniformitarianism lays the foundation and leads to this kind of false circular reasoning, there must be an honest admission of question concerning the doctrine and it must be re-examined honestly by the doctrine’s proponents. I’m putting it mildly.

Related article:

Circular Reasoning in Evolutionary Biology by Henry Morris, Ph.D.

Categories: Creation, Evolution or Both?Tags: , , , , , , ,

2 comments

  1. I don’t actually think there’s an inconsistency here. The rocks are dated using radiometric techniques, while the fossils are subsequently able to be classified (rather than ‘dated’) according to their position. Right?

    • yes… assuming the dates are correct. they’re using the rock layers to date the fossils and then turning around and using the fossils to date the rock layers. there is no way to cross-check radiometric dating. for the dates to be correct another assumption must also be made: long, slow, geologic processes producing daughter atoms very slowly. there’s no consideration that radioactive decay may have been greatly accelerated due to some cataclysmic event in the past which might also give the appearance of aging.

      also, the layering of fossils is not as neat and tidy as the illustration suggests (and there is never a disclaimer in the text books). the many gaps and out-of-sequence layers suggest that the layers and fossils did not form in the way evolution suggests. instead of challenging the underlying presupposition of gradual formation of the rock layers, the interpretation within the uniformitarian framework is adjusted. the assumption of the age of the fossils is not questioned in evolutionary thinking.

      we can look to Adam for a biblical precedent for things appearing older than they actually are. let’s say Adam was created as a 30 year old man. when he was created on day 6, biologically he was 30. chronologically he was less than a day old. he appeared older than he actually was. God created as is. we might also extend that logic to the rocks and stars.

      the appearance of age in rocks could also have been given from any kind of cataclysmic event that also occurred like the Flood.

      here are a couple of resources about the geologic column and the global Flood: The Fossil Record, The Global Flood

      you might also find these articles very interesting. they are fascinating, short reads about known truths we don’t hear from the secular science arena. i plan on reposting them on my blog soon:

      http://www.genesisveracity.com/Articles.htm

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