beausoleil

Isn't this someone or other's fallacy? There is a genetic difference between apes and humans, and humans are more intelligent than apes, but it doesn't follow from this alone that differences in intelligence among humans are genetic.

Dr S

(CL) Its like the difference between an ape and us. There ARE definately genes which grant our larger brain, and thus there ARE genes for 'intelligence'.
(S) When we get to apes we are in my area of expertise.

You are making an assumption. That intelligence is a survival strategy in humans. It is not.
Our brains are larger because our heads are oversized (when you compare them to other primates they are grossly large). In nature when a body part becomes out of all proportion it is only for one thing. Attracting a mate. The tails on peacocks and lyrebirds, the swollen blue faces and rumps of mandrills all secondary sexual attributes.
The outrageously large head meant an outrageously large brain. A much larger brain than was really needed. All this extra gray matter is the source of our intelligence. An extra added attraction, a perk if you will, because of our sexy large heads.
Intelligence is not an end in itself but merely an accident. We consider it so important only because it's what we have. We don't find people with heads the size of chimp heads sexy at all-we call them pin heads-even though it's proportionate to the body by primate standards. We don't want to date people who only hoot and bark.
So no need to worry that people will become stupid because bears are no longer chasing them. Our intelligence comes from our being lovers not fighters.

GeoTheo

Boy, I can't wait to learn more about science so I can refute you, Dr. S.! (Hey there's one way I can keep my brain active.)
You speak with such authority, I think you may give some the impression your views are well accepted and widely held. They are not.
I find them ridiculous. I suppose complex language and self awareness were also bi-products of this "heady" theory of yours?
Intelligence is merely a biproduct of a large head and that we we always be smart as long as we have large heads. What proof do you have to back up this claim?
I would be interested in a formal debate with you somtime as to whether the only fundamental difference between humans and chimps is our headsize.

[ September 03, 2002: Message edited by: GeoTheo ]</p>

K

Dr S:

Many dinosaurs had huge heads and puny brains. If your theory is true, I would expect their brains to have filled up their massive heads giving them cerebral capabilities we could only imagine.

GeoTheo

DR. S.
When you respond to my post please use scientific data. We do have different philosophical viewpoints and I am aware they can cause bias, but I am swayed by science as I am an evolutionist. I find your theory as intellectually stifling as the proverbial "Goddidit!" response. It not only lacks explanetory power, it stifles further investigation. Q: Why do humans have big brains
A: Because we have big heads.
Effectively the question has remained unanswered and begs the next question. "Why do we have big heads?"
"Because chicks dig 'em."
"Why do chicks dig big heads?"
"Because they don't dig little heads."
Whaaa....?????
I don't see any progress here.

Valentine Pontifex

No one has yet to mention a certain story by C. M. Kornbluth....

Christopher Lord

True, there are at least two other factors besides brain size. There is also the organization of the brain, which is most certainly also determined at least in part by genes. otherwise we would all be very different in terms of MRI scans when speaking or looking at pictures of faces (which is not the case).
And the other determining factor is education, which I have stated time and again is not at issue when talking about evolution of intelligence.

So accounting for that, I dont see where you see a fallacy.

echidna

Christopher, could you give us the time scale you're thinking of.

Is your post more about the fact that today’s more inclusive society can more easily perpetuate genes which are detrimental to survival ?

Dr S

(GT) Boy, I can't wait to learn more about science so I can refute you, Dr. S.! (Hey there's one way I can keep my brain active.)
You speak with such authority, I think you may give some the impression your views are well accepted and widely held.
(S) Oh, they are pretty well accepted. Well enough that a large section of one of the episodes of Evolution was devoted to it. You know the series I'm talking about? PBS has rerun it at least four times-whenever they have a fund drive. It's threatening to be shown more often than Joseph Campbell was.
(GT) I find them ridiculous. I suppose complex language and self awareness were also bi-products of this "heady" theory of yours?
(S) It's not my theory, I wish it was. I feel like a dope for not thinking of it myself.
Complex language, self awareness, music, art, culture, science…all the good things that make humans human we owe entirely to the fact that we have a brain much larger than we really need.

(GT) Intelligence is merely a biproduct of a large head and that we well always be smart as long as we have large heads. What proof do you have to back up this claim?
(S) We are not the only primates. There are Bonobos, Chimps and a few species of Gorilla who are all very closely related to us. I'm sure that you know about Bonobos genetic make up and ours being almost 99% the same. Yet they all have much smaller brains, so they can never be as intelligent as we are. Intelligence is the functioning of our brain. So much of the brain is devoted to running your body that for higher intelligence you need a larger mass. Extra brains, as it were.

(GT) When you respond to my post please use scientific data. We do have different philosophical viewpoints and I am aware they can cause bias, but I am swayed by science as I am an evolutionist. I find your theory as intellectually stifling as the proverbial "Goddidit!" response. It not only lacks explanetory power, it stifles further investigation.
(S) It isn't stifling at all, but it is very flattering either. We like to think of ourselves as the peak of evolution. All those millions and millions of years leading directly to us and only us. That's the same vanity speaking that made us declare that the Earth was the center of the universe. Every animal on the planet has evolved for exactly the same length of time. We are no more evolved than anything else. We are not the logical end product of evolution, simply another adaptation amongst many.

Gigantism as a secondary sexual characteristic isn't uncommon. The PBS show focused on the peacock. The idea is that if an individual can support an extravagance that demonstrates good health and means that they are a suitable mate. With the peacock this tail is dangerous. It slows them down on the ground and they can hardly fly. Puts them at great danger from all sorts of cats and bird eating critters. But without the tail peahens will not mate with them. They showed one researcher (in England I think) who clipped the "eye spots" from the most eligible bachelor in their study. The fewer eyespots the fewer mates until they were all gone.

Primates have gone in for this gigantism too. A female Bonobo develops a bright pink lumpy swelling all around her privates. To a human this is repugnant, but to the chimp it's sexually attractive.
Orang-Utan's have developed enormous cheek flaps.
Human primates--compared to the primate norm-- developed enormous breasts. So large that the mother must hold them with her hand so as not to smother the baby. Babies cannot simply hang from the human breast as the mother strolls around, like the rest of the primates can.
We also developed --again compared to the primate norm-- enormous heads. These heads are so large that infants cannot fit through the birth cannel. It was "designed" for our primate ancestors with moderate sized heads. Human infants must be born with their skulls in sections so as not to kill themselves and their mothers. All humans are born premature compared to the other primates.
What makes it worth the risk? The same thing that makes it worth the risk to grow an enormous tail in cat infested country--sex.
Gorillas find large breasts on human women to be ugly (I've asked). Humans find swollen genitalia on Bonobos disgusting. Yet they are extremely attractive within the species itself. Species specific secondary sexual characteristics.

We consider human intelligence to be the crowning achievement of all the creatures on Earth. But why? It lets us do all sorts of things that no other species has an interest in. We think that it is wonderful-we even want to find creatures on other planets that share this one single adaptation. And yet every other species on Earth is quite content without doing them.

I'm sure if you asked a peacock you would find that the highest degree of evolution on Earth is not intelligence but enormous tails. They think it's sexy. We think we are sexy.

Christopher Lord

Certainly, thats exactly what I'm thinking.

I'm sure we will start steering our genes soon anyways and the point becomes moot, but if we dont, for whatever reason, or certain sub-populations dont, then its quite likely we will drift back towards a less over-engineered state, I think.