Human Brain Evolution Was a 'Special Event'

Let's see; thousands of mutations (at most, according to the article) in 20 million years (at the least, according to the article) -- that works out to20 million / thousands = 20,000 years for a couple of mutations.Is this really so unbelievable?

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"The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one." -- George Bernard Shaw

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The mutations must could not have occurred long before homoerectus since we know that the Australopithecus had about the brain size of a chimpanzee.

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So? Even if it's "thousands" of mutations since Australopithecus, that's "thousands" in 5 million years, or about one mutation in 1000 years or so.Still doesn't seem too unreasonable to me, but then, I'm not a creationist.

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"The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one." -- George Bernard Shaw

Huh? I thought that you were thinking that it was "remarkable" that "thousands" of mutations could occur in such a short time. Am I now correct in assuming that you now realize that it isn't so remarkable? That "thousands" of mutation in a few million years is just one or two mutations in a thousand years or so. Which sounds reasonable to me. I thought that this was the point that you were trying to make. Were you skeptical that "thousands" of mutations could occur in such a "short" time? Do you now see that the time wasn't so short after all? Would you agree that one or two mutations in a thousand years isn't so unreasonable?As far as your new question is concerned, I don't even know whether they know which genes are involved in brain development. If they don't know which genes are involved to begin with, they certainly couldn't know exactly what the mutations were, could they?

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"The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one." -- George Bernard Shaw

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It still is remarkable since the history of civilization is over a few thousand years or so, then have any mutations occurred throughout history that we have discovered?

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You are really moving pretty far from the points in your original post. First, you claim that there is a paper that exclaims that "thousands of mutations in 20-25 million years is remarkable". Then you decide to change this to the 5 million years or so since Australopithecus. Now you want to narrow this down to the few thousand years since civilization began. I'm not sure what the relevance any of this has to your original post.-

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Have our brains grown bigger

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You mean over the last 10,00o years or so of known civilization? Not that I am aware of.-

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are we still evolving?

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Probably. People die; some die before producing offspring. This is what is required for natural selection to operate.-

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The problem with evolution theory is that it still does not have the smoking gun - the actual mechanism of beneficial mutations charted out.

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I don't see this as a problem. I suppose that it would be nice to know, but we already have a lot of evidence that evolution has occurred. It is pretty much a fact that evolution has occurred. That is what the overwhelming evidence shows. Whether or not we have a list of the exact mutations doesn't make all the other evidence go away.-

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Alternatively, one can propose that a grand Designer designed all the creatures starting from simple to complex allowing each creature to adapt to its habitat and undergo minor changes as it does

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One can propose such a thing, but producing scientific evidence in support of this proposal is another.

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"The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one." -- George Bernard Shaw

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That is not what I said.

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Yes it is. You are the one that presented the paper for our consideration. You are the one you seems to feel that the paper presents an interesting challenge.-

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The scientists said in the paper ,"thousands of mutations in 20-25 million years is remarkable" .

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Yes, and then when it was pointed out that some of us don't see it as particularly remarkable you began to change the problem. The authors mentioned thousands of mutations in 20-25 million years, and then you, without justification, decide to change it to the 5 million years since the time of Australopithecus, and then to the 10,000 years since civilization began. The paper is talking about the thousands of mutations that may have occurred in 20-25 million years -- the beginning of civilization or the time since Australopithecus is irrelevant to the parts of the paper you quoted.It's alright to go on to other topics -- the initial post seemed to ask whether the paper presents some sort of problem, the answer is that it doesn't, and so that would make a pretty short thread -- but when you go on without acknowledging the previous point has been addressed you come across as unfocused.-

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Then YOU claimed that this is not a problem and it only requires a few mutations in a thousand years.

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My claim was justified. It is simple arithmetic. It's not rocket science -- hell, it's not even College Algebra.Take the total time, divide by the number of mutations, and you get the average length of time between successive mutations.20 million years / "thousands" = about 10000 years between mutations.It really is that simple. According to the passage that you quoted, we have about one mutation every 10000 years. I fail to see anything remarkable about it -- if there is something remarkable about it, then you haven't quoted that part.-

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Regardless of how valid you think evolution theory is, you have to admit that there is a very little that we know about the evolution of the brain.

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That may be true. If it is, then it is an interesting exercise for scientists to try to work out the details. But just not knowing the details of a process isn't evidence that the process didn't occur.-

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Similarly we know very little of how complex organs have actually developed - there are numerous theories but no actual evidence.

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Actually, we have lots of evidence that evolution occurred. The heirarchical classification of the species. The fossil record. The findings in genetics and molecular biology. The patterns we see in Endogenous Retroviral Insertians, vestigial organs, and atavisms. And so forth.-

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This is the major major stumbling block of evolution theory .

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Since in actuality, evolution has always been based on evidence, and the evidence has always supported the theory of evolution, this is no stumbling block at all.

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"The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one." -- George Bernard Shaw

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they see it as a remarkable event.

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Evidently they do. But it isn't clear what it is that they find so remarkable. It can't simply be the number of mutations. Over 20 million years, thousands of mutations doesn't seem to be so large.-

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but a creationist will see this as furthering their cause

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Creationists see everything as furthering their cause. The hierarchical classification of the species is excellent evidence for evolution, yet creationists see it as furthering their cause. There are many good evolutionary lineages in the fossil record (the lineage from A. afarensis to H. spapiens being one of the good ones), and creationists see them as furthering their cause. I honestly can't think of anything that wouldn't further their cause short of Jesus Christ himself returning to earth and telling them to knock it off.-

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However, research in this field will either prove or disprove the mechanism of random mutations because of the time span (relatively short) that needs to be investigated.

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I doubt that the research will either prove or disprove evolution. For one, evolution is already as well "proven" as a theory can get -- there is already a tremendous amount of evidence that supports it. And to disprove evolution -- well, someone would still have to deal with all the evidence that supports it.-

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There is no evidence that the brains of Australopithecus was larger than chimpanzee.

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It's also irrelevant to the points in the paper. They were not only estimating the number of mutations that simply increase brain size -- that might be a much smaller number. Evidently, they were estimating the number of mutations that might have occurred in the last 25 million years. So, the time since Australopithecus is not relevant to their estimate.-

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Additionally, from the dawn of civilization there was more natural selection pressures from humans to have even bigger brains and thus there should be some small indication of change from that period.

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Actually, there would have been some selection pressures for smaller brains -- the large head of a baby at birth puts the mother at increased risk during childbirth. Mortality of both baby and mother were relatively high in the good old days. Also, large brains take more energy to develop and maintain. As it is, the brain is one of the most energy hungry organs in our bodies. I would say that there is a clear equilibrium between large brains and smaller brains.-

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Actually I might have to restate what the major stumbling block of evolution is: when scientists start believing their little stories they make up (which are actually scenarios thought to fit the evidence and subject to change) as religion.

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That might be a stumbling block. But as long as the scientists continue to collect data, compare the data to the theory, and modify or discard the theory as the data suggests, then I don't think we have too much to worry about this particular stumbling block.The clear stumbling block, in my opinion, is when religious fundamentalists start believing their myths as fact.

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"The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one." -- George Bernard Shaw

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And all I am saying from this bit...is that this rate of evolution must have happened in the time during erectus and after A. afarensis .

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Except that you cannot get that from that paper. The paper is comparing humans to macaques. Their estimate for the number of mutations, therefore, is for the time period since the last common ancestor of humans and macaques. Australopithecus is irrelevant to their estimate.-

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If I am wrong then please tell me during which period when most of the brain evolution took place ..

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I don't know. You don't know, either. Maybe no one knows; if someone knows this, then it will be in a different paper than the one that you chose. You will have to find a paper that estimates the number of mutations since Australopithecus. The paper that you chose is inappropriate for this.

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"The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one." -- George Bernard Shaw