Ancient Art and Cognition

Today’s DpSU from Mr Thomas of the ICR is on the subject of the 100,000 year old South African paint lab, and is called Ancient Paint Workshop Challenges Human Evolutionary Story. Now, whatever makes him think that?

One of the abalone shells, placed on a rock. From AAAS/Science, via Why Evolution Is True (linked)

His primary objection begins like so:

According to standard evolutionary dogma, mankind did not start evolving advanced cognitive abilities until about 70,000 years ago. Christopher Henshilwood, lead author of the study that appeared in Science, told Nature News that these artifacts “push back by 20,000 or 30,000 years” the imagined advent of “complex cognition,” or the time when humans finally had the brainpower to prepare and use paint.

You’ll find the Nature News article linked above the image, and I advise you to start there (and at the place the image itself links to) if you managed to miss the coverage of the find, back when it was still news.

Considering that ‘cognitive abilities’ is pretty subjective, I for one have no problem with evidence that would push back the date that it evolved a few tens of thousands of years. After all, it is an inherent property of ‘earliest known x’ records that they almost always mover further back in time.

Brian Thomas continues with a questionably relevant and probably out of date quote from the person who found Lucy, and then goes on to give his explanation as to why our dates for the evolution for cognition might all be consistent: as you should know by now, the creationists dispute any and evry dating mechanism science has on its hands.

But before I get to that, I must present to you two paragraphs which, amazingly, show that Mr Thomas actually understands the real limitations of 14C dating:

The study authors performed three different dating techniques on the remains. Curiously, however, they did not carbon-date any artifacts. Some of the tools included cow, seal, and dog bones, and the abalone shells must still contain protein. All of this material should have datable carbon. Why were they not carbon-dated?

The answer probably has to do with the fact that carbon dating is unreliable for artifacts older than 60,000 or so carbon-years. If any carbon-14 was detected in these remains, then the carbon age would be no more than 60,000 years, and probably far fewer—thousands of years younger than these scientists’ target date.

He, of course, implies in the last sentence that the scientists were looking to get a specific date, and so couldn’t use the 14C method as that would get them a lower age. He was doing so well before that. The point is that, unlike what the creationists would like you to believe, 14C decays not to zero but to a small, background level that would indeed date to a more recent age than 100,000 years. This is why, whenever the creationists date million-year-old things they always come up with a date that is generally less than an order of magnitude more than their age of the universe, and several less than the real age of the object.

Anyway, he goes on:

In their Science report, the archaeologists showed dates on a photograph of several vertical feet of cave floor layers. However, one dating method showed an age of 100,000 years for a layer that was dated at only 75,000 years by another method. And there were other inconsistencies, raising suspicion over the reliability of the age assignments.

I can’t see the original Science paper beyond the abstract, so I don’t know what he means here.

And there is more. They labeled the very top eight-or-so-inch-thick layer “hiatus,” instead of assigning it an age like the other layers. Then they labeled the next lower layer at about 68,000 years. Why would nine feet of cave sediments accumulate over 32,000 years, then almost no sediment accumulate for 68,000 years?

I was under the impression that you labelled gaps, not layers, as hiatuses, but whatever. Gaps of hundreds of millions of years are known – 68,000 years is not all that impossible. The sediment is in a cave, and changing patterns of water channels could easily have this kind of effect.

He changes tack:

The idea that man evolved his cognitive abilities has no scientific support, either. Cognitive thoughts are not traits encoded by particular genes, but immaterial traits. Thoughts interact with the material world through the sophisticated architecture of the brain, which requires thousands of precisely interacting genes. Tinkering with brains or brain-developing genes brings disaster, not improvement. Thus, brain biology shows that modern human cognition must have been purposeful and present at the beginning.

This idea of his is based on the concept of dualism – where there legitimately is a difference between the brain and the mind. Ironically, this has ‘no scientific support.’ On the other hand, we can see that many other animals have (lesser) cognitive abilities, and determine what the primary differences between our brain and theirs are. We can also take people with brain damage, and determine that there are legitimate differences in, well, everything about them. On the other hand, you don’t seem to be able to do the same thing when it comes to providing evidence in favour of dualism. Cognitive thoughts may well not be “traits encoded by particular genes,” but they do indeed seem to be the emergent properties of the genes.

Nothing remains but to point out that his conclusion is therefore flawed, and to echo the little image disclaimer below this particular article:

Image credit: Copyright © 2011 AAAS. Adapted for use in accordance with federal copyright (fair use doctrine) law. Usage by [Eye on the] ICR does not imply endorsement of copyright holders.

(NB: the image that they use is not the same one as I do).

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One thought on “Ancient Art and Cognition

  1. To post or not to post?

    Is it worth arguing with stupid?

    Is it worth arguing with Brain Thomas?

    But I am repeating myself.

    Here goes anyway.

    Science is based on facts. Faith is the evidence of things unseen. Facts are the evidence of things seen, recorded, and measured.

    A scientist, when speaking ex-cathedra (say, from the Isaac Newton Chair in Cambridge) uses words like: hypothesis, theory, and law, with very particular meanings known to his scientific peers and to anyone else prepared to make the mental effort to understand them. This in no way detracts from the common meanings used in everyday speech. Likewise, when a scientist uses words like: belief or truth, he uses them loosely as in everyday speech; science neither believes in truth nor believes in belief.

    At death, the things that one has believed, go with one. The things that one has contributed to science live on for those remaining to use, build upon, or refute.

    There is no point in the philosopher, theologian, or, in particular, creationist, coming to the scientist for establishing the truth or even for justifying his beliefs. Science can give you a law or a theory or even a hypothesis but these are only the best available explanations based on the available evidence. They will change as more evidence becomes available. This is the limitation of science but also its strength. Truth is an inflexible concept. Belief can hold onto it for so long but then it gives way. The Earth is not flat, it is not the centre of the solar system, it is not 6000 years old.

    We know the Earth is not 6000 years old BECAUSE WE HAVE MEASURED IT!

    This measurement is very difficult to perform but it depends on simple laws giving the radioactive decay of uranium. Anyone who is willing to buy or build the facilities required and who takes sufficient care, will obtain a very similar answer – 4.5 and a bit billion years. The uncertainty is more in defining what we mean by the age of the Earth than that in the measurement itself. The age of the Earth is found to be slightly more that the oldest terrestrial rock and slightly less than the oldest solid material in the solar system.

    Creationists do, and indeed must, deny these measurements. They raise many valid scientific objections. Valid, certainly in the days of Rutherford et al. over 100 years ago but becoming increasingly less valid as methods were refined. Measurements are now done with great precision. The accuracy of dating a particular item depends on many factors: the ability to obtain a datable sample that corresponds in age to the selected item, the ability to process this sample for measurement without contamination, using the right measurement technique for the sample in question, and so on. In short, it is easy to get it wrong. Fortunately many techniques will show up the error as part of the process. The longer answer would include that where the item to be dated is a widespread event and representative samples are easy to obtain and the measurements can be done by many laboratories using different methods, both precision and accuracy can be very high indeed.

    Creationists need to be able to argue that there is some systematic reason why the measurements are different by up to six orders of magnitude from the true answers (I make no apology for using the word true because this is the word they would use). Belief is brought in when justifying it to believers but there is nothing that science can add or subtract from that. When justifying it to scientists the argument turns to overthrowing well established principles especially those that are expressed in the values of the fundamental constants – this is of course an oxymoron, if constants can change they are not constants, it is the laws themselves that need rewriting. What is lacking is a creationist set of laws that explain all the measured results of historical events and still explain current events. What they really want is to be able to tweak one constant (variable) by an arbitrary amount for long enough to obtain the require result and then tweak it back without anyone noticing. The catch is that it would require a vast number of tweaks to get the required answers and then an even greater number to cover up the evidence that they have done so. Finally, when justifying it to the great unwashed, creationists fall back on the conspiracy theory – all scientists are in collusion to prove evolution. Quite what the arrangement is is never explained. Do brown envelopes full of money change hands? When fixing the results, does the person measuring the potassium fake the result or is it the person in another lab measuring the argon; where do the people designing and building the mass-spectrometers and other equipment fit into the scam?

    Answering some of Brian Thomas’ particular remarks. Dating artifacts of 100,000 years or less is very difficult. One reason is that the Earth is so old only the isotopes with extremely long half lives, and their daughter products remain. Thus one is faced with using one of these very long half life isotopes. In a short period the decay is very small and hard to measure. This has actually been confirmed by a creationist. Dr. Steven Austin from the Institute for Creation Research took a sample of lava from the crater of Mount St. Helens and submitted it for potassium-argon analysis to Geochron Laboratories of Cambridge, MA, a high quality, professional radioisotope dating laboratory. Geochron were not well equipped to do this particular type of measurement (and no longer offer that service) and stated that they could not date anything younger that 2 million years. (There are better methods for doing this.) Not surprisingly he got an inaccurate result – 0.35M years. But really his methods were too sloppy to give any meaningful result.

    One thing in favour of science is that the results tend to build up and are strengthened as time goes on in spite of the theoretical possibility that it could all be pulled down by new evidence. Thus the theory of Relativity (both Special and General) served to confirm Maxwell’s equations and added terms to Newton’s equations while throwing new light on both. Science is ongoing and does not tend to backtrack over already established things unless new evidence demands it. The truth is, scientists realised over 200 years ago that the Bible did not provide an adequate explanation for observation, 100 years ago they could make a reasonable measurement of the age of a rock, now they are able at great cost to do accurate measurements. Thus it would not occur to them to do a carbon dating of something that measures outside of the usable range for that method.

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