Carrie

Why did Homo Sapiens make it, but not the other Hominids? How did we get so smart? Neanderthal man was smart. Smarter than a chimp or a rhino or an aligator, but they survived while Neanderthal mad died off. Why couldn't Neanderthal man survive?

It's just weird to me that we're so different from all other animals, as far as our intelligence. Why didn't tigers get really smart? We know dolphins are pretty smart, but they just can't do much since they don't have hands. They're smart, but they can't build skyscrapers or play the guitar. How is it that we are the only animal to become so...amazing?

Maybe only one species can be dominant at one time? If there were another species as smart as us, or close, they'd be competing with us, so we'd kill 'em off. Unless we could interbreed with them. If, for example, an intelligent alien species came to earth, it's unlikely that we could interbreed with them. They wouldn't be potential mates or family, so they'd just be competition for resources, and there would be confict. We'd probably try to get rid of each other. For sure each species would try to dominate the other. One species would win out; the stronger more intelligent species.

So if Homo Sapiens and Neanderthal man (or some other hominid) lived at the same time, we would have tried to kill them off, or interbreed with them. I'm guessing that only one species can dominate at one time, and since we were smarter, we won.

There can be no others like us. If all of a sudden chimpanzees started getting smart, and started demanding their rights, and wanted things to be a certain way, we'd put a stop to that pretty quick.

So is that maybe why we're the only ones like us?

Viti

IIRC Neanderthals actually did lose to our ancestors, Cro Magnon. We either killed them or they couldn't compete or a combination of the two.

Arken

I believe that Neanderthals survived Cro Magnons and it was we Homo Sapiens Sapiens that killed them off (or mixed them in with the population through interbreeding, some say)...

Interestingly, some also have theorized that the Basque people in Spain may have quite a bit of Cro Magnon in them. They have a unique bone structure, a unique blood type (RH-) and a language totally unrelated to any other language in the world. I have no idea how much truth their is to it, but it is an interesting possibility.

Chiron

Carrie: "We know dolphins are pretty smart, but they just can't do much since they don't have hands. They're smart, but they can't build skyscrapers or play the guitar."

Or can they? Dolphins Evolve Opposable Thumbs: 'Oh, Shit,' Says Humanity
(edit: this was already referenced in a similar thread, but because I didn't see it, this still counts. Yes!)

Seriously, though, this amazingness has only come within the past few thousand years. Once we reached 'critical mass' of culture, language, and technology (IMO) we suddenly began to skyrocket. Also, these things were good survival traits. Like you said, it might not be so great for chimps if they started this, given that we've already got most of the inhabitable land area.

-Chiron

GPLindsey

One could also extend the question to ask why some cultures around the world have advanced incredibly over the last few thousand years, while other cultures have not progressed past the stone age (the Bushmen of the Kalahari, some Indian tribes in the Amazon, etc.). The people of these cultures are just as human as the rest of us, and are capable of the same feats. But variables like environment (or lack of changes in environment?), competition, tradition, etc., have kept them unchanged for thousands of years.

It is a little unnerving to think that, if it weren't for a few key variables over the course of human history to drive us to greater technological improvements, we could still be just a planet of happy stone age hunter/gatherers. We'd have the brains to build computers and fly into outer space, but not the curiosity to start us down that road.

Non-praying Mantis

BTW, Cro Magnons are Homo sapiens sapiens. It was the Cro Magnons that were around when Neanderthals became extinct.

NPM

Doubting Didymus

I don't immediately see why human intelligence cries out for a special explaination. It's certainly a selective advantage. You might as well ask why rhinos are the only animal with two central facial horns.

Godless Dave

I can't comment on the biological facts you mentioned, but their language being "totally unrelated to any other language in the world" should not be considered evidence of Neanderthal ancestry. Languages don't leave fossils and they change very fast. We don't even know that Neanderthals used spoken language. I don't remember exactly when Indo-European languages first showed up in Western Europe but it was a LOT more recent than 35,000 years ago when the Neanderthals died off.

BTW, Finnish, Estonian, and Hungarian are related to each other but not to any other known languages in the world.

Peez

Hi Carrie. Just an aside: it should be Homo sapiens. This is a good question, and we can only offer conjecture.Evolution can be quite complex, and is rarely as simple as looking at one particular trait and asking why it evolved. Intelligence is the result of a complex central nervous system (CNS), which seems to require a somewhat larger CNS than would otherwise be needed for a given body size. That is, a larger animal needs a larger brain just to keep things running, so a basking shark may have a bigger brain than a Chihuahua, but that doesn't mean that it is smarter. Note than men have, on average, bigger brains than women but are no smarter. What seems to matter is the complexity of the brain, though this does seem to require a larger brain compared to the body.

Also keep in mind that "intelligence" is hard to define, but it is not a "have it" or "don't have it" thing. There are animals that are more intelligent, those that are less. That being said, humans certainly are noticeable bright compared to our relatives. We also have very large brains for our size.

Now, it might seem as if smarter is better, but not necessarily so. Brains are very expensive. I know that you don't just buy your brain (at least, not yet ), but it costs your body a lot of energy to grow such a large and complex organ. It also costs in terms of the added risk to childbirth, as the brain is the most difficult part to get safely out of the human mother. Even when you have grown up, your brain consumes a great deal of metabolic energy to maintain, energy that could have been diverted to surviving starvation, or outrunning an enemy, or fighting a competitor, or eliminating a disease. Thus, being smart offers advantages but is also costs in terms of survival and reproduction.

As with any adaptation, intelligence likely evolved in humans because the benefits outweighed the costs. Because intelligence is so costly, it seems to require fairly specific conditions to allow high intelligence to win out. Of course, human evolution was not a simple linear process from ancestors with brains the size of a chimp's. There were a number of different branches. Their extinction is hardly surprising, more than 90% of the species that have ever lived have gone extinct. The reasons that any one Hominid went extinct could have to do with intelligence, or it might be entirely unrelated.Why is the Blue Whale so... amazingly big? Why are there bacteria only 0.1 microns in diameter? These are interesting questions, but while humans are quite unique, there are many things in the natural world to amaze us.The "more intelligent" species is not necessarily the one that would win, though high intelligence does give us quite an advantage. I would tend to agree that we would probably compete with a second intelligent species on this planet, much as we compete with so many other species here. However, humans were rather restricted in distribution through most of our evolution from the chip/human common ancestor.Typically if two species are competing for the same resources, one will eventually drive the other to local extinction. That may well be what happened to Neanderthals.That might work now, but it wouldn't explain why orang utans didn't evolve higher intelligence before humans spread into their habitat.

Peez

Doubting Didymus

There's the sexual selection theory, of course...

I happen to have a copy of Geoffrey Millers The Mating Mind on my shelves, but it keeps managing to become buried under other things. Has anyone read it? If so, I'm interested in what predictions Miller proposes, and how they hold up as regards evidence.