Evolution or Devolution?

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. Everything breaks down from order into chaos given time unless subjected to an ordering influence (such as you tidying your house).

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You have a basic misunderstanding of thermodynamics, and part of it is revealed here. When your house spontaneouslly gets messy, it is obeying the Second Law of Thermodynamics. When you tidy your house, you are also obeying the 2LOT, otherwise you couldn't do it. When an organism grows old, dies and decays, it is obeying the 2LOT. When an organism is born, grows and becomes more complex, it is also obeying the 2LOT. The 2LOT by itself simply does not tell you whether a particular system is going to get more or less complex or more or less ordered. So it cannot tell you whether evolving biological systems are going to get more complex or less.We know that organisms reproduce themselves, and we know that their DNA changes as they do so, so the process of reproduction and mutation cannot violate the 2LOT. We know that some mutations are detrimental to an organism in its particular environment and that some of them are beneficial, so the process of differential reproduction (i.e. natural selection) cannot violate the 2LOT. Those two steps are all that there is to adaptive evolution. So what is it about evolution that violates the 2LOT?

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Surely one verified exception should be enough to make us challenge or question what we had formerly believed to be received wisdom. When an atomic clock was taken on board a plane and returned to land showing a different time to the clocks on the ground no-one said that the time dilation effect was disproved by all the other clocks saying the same time.
Isn't it after all surely the exception that proves the rule?

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One verified exception should be enough to challenge our understanding of how brains can and do work. You weren't asking about human brain function in general, however: you were asking about the evolution of brain function. For that question, the exception may not be important at all. If 5% of people can develop successfully with much of their cerebral cortex missing but 95% can't (as seems to be the case from your references to hydrocephalic individuals), then having a complete brain is a massive evolutionary advantage.

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With all due respect what gave you the impression that i thought that tidying one's house disobeys the second law?

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You did, when you wrote

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Everything breaks down from order into chaos given time unless subjected to an ordering influence (such as you tidying your house). Our bodies, the houses we live in, everything is subject to the second law of thermodynamics. Living things are not exempt. We are all subject to ageing and death.

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You appear to be implying that aging, death and mess are all examples of the operation of the 2LOT. They're not, any more than birth, growth and cleaning are. If you're not saying that, then I have no idea what you're trying to argue here.

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I have never claimed that evolution violates the second law or denied that adaptive evolution takes place. I am merely questioning the direction of that evolution and examining what i believe to be clues which were elaborated on in more detail by Kerner in his book that perhaps the direction of that adaptive change might be such that our species might evolve into one with less functional brain capacity and that perhaps this has already happened to some extent.

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Kerner says that the 2LOT means that a "positive" direction to evolution is "absurd". He is indeed claiming that the evolution of humans from small-brained apes is a violation of the 2LOT. Do you agree with him here or not? If you don't agree, why did you quote him?As for the direction of adaptive change, it's entirely possible for brain size to decrease as an adaptive change: brains are expensive things to maintain, biologically speaking, and there would be an obvious advantage to having a smaller one. All the evidence we have, however, indicates that brain size and functional capacity have gotten steadily larger over the last several million years.

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I'm just going from memory, but I believe Homo erectus is the only human ancestor we know of that had a larger average brain capacity.

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No, erectus had a smaller brain than sapiens.

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Homo erectus did not have a larger brain capacity than modern humans but Homo neanderthalensis did have a larger brain capacity than us.

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Neandertals, however, are not in the direct lineage of anatomically modern humans. All the ancestors that we have evidence for had smaller brains than we do.

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In explaining that the second law suggests that everything tends towards states of greater disorder unless subjected to an ordering influence. I am not saying or implying that such an ordering influence refutes, invalidates or breaks the second law. If I can make a distinction between what I have said and what you seem to be reading in what I have said with an analogy then perhaps I could do it as follows:
In one of my earlier posts I was referring to different ways in which one could explain how gravity causes an apple to fall from a tree. In fact, one could see that generally an apple suspended above the ground will always fall unless it is subject to force countervailing the gravitational force of the Earth. The fact that the branch and the twig holding it to the tree are still intact preventing it temporarily from falling would not be seen as a refutation of the law of gravitation. In the same way the temporary presence of an ordering influence doesn't of itself contradict the second law of thermodynamics.

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I have a couple of concerns with your treatment of thermodynamics in this thread. One has been pointed out by Percy: you are using "order" and "disorder" without defining them precisely, while in thermodynamics they have precise definition. Your examples are not reassuring. Cleaning a house, for example, may result in a system that has either higher or lower thermodynamic order. Similarly, aging has nothing to do with thermodynamic notions of a tendency towards disorder (which is a good thing, since otherwise it would be hard to explain why most organisms don't age). Mentioning the 2LOT in this context can cause nothing but confusion.Precise definitions here are important, because the first thing you have to do, assuming you actually want to apply thermodynamics to large-scale evolution, is to determine how the state of the system changes during the course of evolution. To put it simply: which has more thermodynamic disorder (e.g. entropy), 200 pounds of bacteria or 200 pounds of human? That's the only kind of disorder that thermodynamics is concerned with.Your gravity analogy brings up a second concern. In your analogy, the branch prevents gravity from causing the apple to fall. There is an analogous situation with living things and thermodynamics. Living organisms really do stay far from thermodynamic equilibrium, and there must be something that permits them to do so. That force is the energy input from the sun. I think we're all in agreement that were the sun to go out, all living things would eventually. What I don't see is why you think any other force is required here.

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For the record I do agree with Kerner that a spontaneous "positive" direction for evolution of man from small brained creatures is absurd.

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Why?

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In the Britanica Online definition of 2LOT it is written.

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"The second law states that, in a closed system, the ENTROPY of the system does not decrease."

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If entropy is expressed by terms of order and disorder and the 2LOT makes reference to entropy then surely 2LOT is expressed in the same terms.

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Entropy is not usually expressed in terms of order and disorder, except in vague, hand-waving descriptions for non-scientists. Scientific definitions of entropy are usually made in terms of the availability of energy to do work (classical thermodynamics) or of the probability or state-density of a system (statistical mechanics). Scientifically, entropy is defined by reference to measurable quantities. Sometimes the word "disorder" is attached to one of those quantities (so that highly probable configurations are called "disordered"), but this amounts to a particular (and peculiar) definition of "disorder", rather than a definition of entropy in terms of the commonly understood concept of disorder.

It is quite clear that Neandertals provided either very little or zero genetic input into modern humans. More to the point, it is also clear that anatomically and behaviorally modern humans evolved in sub-Saharan Africa, where Neandertals never lived. Modern humans were technologically and culturally more advanced than Neandertals well before the two groups encountered each other (if they ever did). Any account of modern humans devolving from Neandertals is simply fantasy.

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There are other problems with drawing such definite conclusions about the neanderthal contribution to the human genome. First, the results pertain only to mitochondrial DNA which is only passed from mother to child. So, if there were some interbreeding and it were generally the case that the husband moved to join the race of his wife there would be no trace of Neanderthal mitochondrial DNA in the modern human genome. If Neanderthal nuclear DNA were studied then the results would be more accurate as nuclear DNA is passed on by both parents. However, as yet no examples of Neanderthal nuclear DNA have been successfully extracted so there is no conclusive evidence that Neanderthal nuclear genes have not been passed on to the human gene pool.

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It is true that only mitochondrial Neandertal DNA has been studied. There have been numerous studies of X, Y and autosomal genetic diversity in modern humans, however, and they all paint a consistent picture, one in which modern humans evolved in Africa and subsequently spread elsewhere, with little or no genetic input from non-African archaic humans. It is not impossible that there are bits of such archaic DNA here and there in modern genomes, but the overall demographic picture means that they would be regional variants, present in some geographic areas and not in others; there simply has not been enough gene flow back into Africa for them to have become fixed in the entire population. So whatever genes Neandertals might have contributed to modern humans, they weren't many and they won't be present in much of the modern population. Anything genetic that characterizes our species as a whole did not come from Neandertals.