Bones of Contentions.

There are other anthropological explanations for human brain size, most of which are not mutually exclusive with each other or with the "size/intelligence" explanation.I would say that the problem for anthropology is not a lack of explanations but a surfeit of them, and no immediately clear way to distinguish those that are correct from those that are merely possible. Nonetheless I would say that situation falsifies your position that large human brains are an evolutionary mystery.

I haven't followed RAZD's posts in this thread so I have no ability to judge. I'm simply offering an alternate line of discussion. Well, naturally. IQ measures education, not innate mental ability. Why would we expect to see a corellation between brain size and IQ? Between IQ and income level, perhaps. (Which we do.)A better question is, do our larger brains bestow mental abilities that we wouldn't have otherwise? I don't know. Does the fact that humans experience loss of faculty when portions of our brains are removed suggest that we do?

I don't know what "evidence" you think you have, but try reducing your brain mass by 50% and see if your capacity for mental function isn't drastically decreased.It's beyond question that there's a gross corellation between brain mass and mental capacity. I don't see in what rational way this proposition can be disputed; certainly not with the true assertion that there's little or no corellation between small-scale brain size variation and the degree to which you can absorb education. From Alfred Binet. Maybe you've heard of him? He's the inventor of the IQ test, named after him in it's most modern incarnation, the Stanford-Binet V. Well, no, they don't. IQ experts and psychologists agree that IQ tests measure what they're supposed to measure - the degree to which the subject has absorbed the educational objectives appropriate for his age-peers.That's why your IQ changes as you age, why it can go up or down - sometimes you pull ahead of your peers, sometimes you fall behind. IQ is based on age. An adult with an IQ of 100 is way, way more educated than a child of the same IQ.In regards to what IQ measures, let's look closer at that Standford-Binet V. The test itself gagues performance in five key areas:Fluid Reasoning
Knowledge
Quantitative Reasoning
Visual-Spatial Processing
Working MemorySee? "Knowledge". Since none of us are born with knowledge, since knowledge is not an innate quality of the human brain, another way to refer to "knowledge" is "education." And all the rest are skill areas that can be improved with excercise, like video games, puzzles, or even taking IQ tests.The inventor of the test invented it to test education. The test itself gagues your education. Scores on the test are positively correlated (prior to "correction") with socioeconomic status - in other words your access to quality education. Proposition proved, as far as I can tell.Exactly who do you have that's telling you the test measures something other than education? Because they're wrong. What does the test measure if not education?This message has been edited by crashfrog, 08-08-2005 07:31 PM

There's no selection pressure for larger brains (and considerable pressure in the developing world against), but there's considerable evidence of increasing IQ over time. It's a well-known neurological fact that the IQ of a population increases over time.But, of course, IQ is not intelligence, but education. Since there's no way to measure innate mental intelligence, nor any consensus on what that would actually be, you've asked an impossible-to-answer question (presumably to set your argument behind a bulwark of invincible ignorance.) Humans are apes. How could there be a transitional fossil between two things that are the same?

To what evidence do you refer?

I think you misunderstood what I was saying. You asked a question in the context of larger human brains, I answered in that context.Clearly there was, at one point, a selection pressure on larger brains. That pressure appears to no longer exist - and in fact, the opposite pressure may have existed for a period of time, when agriculture replaced hunting and gathering as the main means of human food production. No, I met my wife playing Dungeons and Dragons. (And I don't know anybody who goes there to look for a wife, either.) But, once again, you don't appear to have understood what I said."Ape" is not a species, it's a larger group than that. Like "mammal." Humans are part of that group. It doesn't make sense to ask for a transtition between a group and a member of the group.Humans mate within their own species. (Mostly.) All humans are apes, but we're different apes than the other species of apes.I would caution you about jumping back into debates like this after such a pronounced absence. Unless you are careful about reading the previous posts and not simply the latest round of replies, you're likely to commit the same grave errors of misunderstanding that you have committed here.