Urbanredneck, what is this “evolving higher” that you speak of? All organisms are highly evolved, and all organisms are evolved to fit their current niche. Our ancestors were evolved to their niche just as truly as modern chimps are to theirs. And a single-celled organism is also evolved very well to fit into its niche.
You can make a list of our charateritic traits and how they contributed to uour current situation…
Binocular vision, thumbs and grasping hands, tool making, speech and language, omnivorous, bipedal, lacking in weaponized body parts… This list goes on. One of the other points is how nature provided the path that allowed each of these to appear over time.
As climbing animals, grasping hands and thumbs were useful, unlike, say wolves or cats who needed all four feet. Climbing trees got us ready for bipedalism, so longer forays on the ground resulted in bipedalism rather than a return to quadrupeds. Free hands allowed us to hold things (food, sticks) which also encouraged bipedalism and grasping. having hand probably encouraged brain development for coordination, which lead to finding better uses for tools, and so on. Once we learned to like meat, a handy source of protein, having weapons meant that even without claws or hooves or fangs, we could kill our prey.
Raptors might hunt in packs, but did they then need any brain for anything beyond stalking? they already had nasty enough claws.
To elaborate - Raptors might hunt in packs, but did they then need any brain for anything beyond stalking? They already had nasty enough claws. No incentive to develop creative ways to kill with pointy sticks or big rocks, no need to develop grapsing or toolmaking skills that might be applied to basketweaving or making corrals. Running very very fast means no need to develop subterfuge and the language to organize with other hunters. And so on.
The human experience is unique in that regard, I guess to repeat the OPs question - why?
The other question I have regards the develpment of civilization. Humans have been around, in current state for for 50,000 years to 100,000 yearsor more - yet only got to agriculture and civilization in the last 15,000 years. Yet, once these same primitives crossed to North America from SIberia, they developed (independently invented) civilization within 10,000 years or so. What happened to our brain to make this explosion possible world-wide?
Our distant ancestors were evolved for their niche also. Many theorize they were displaced from their niche leading to the evolutionary changes that resulted in animals that could argue about this subject. Their niche may have disappeared, they may have over-populated it, or they may have been driven out by another species. If something like that happens to a species of great apes (or a species of just OK apes) they are closer to ending up as we did than other species. If it doesn’t happen then it’s still more likely that a random change, beneficial or not will lead them to becoming advanced tool makers like we are, again because they are closer to that than other species. Not more likely that the environmental change or random change will occur to apes, just more likely that such a thing will produce a wheelwright.
Even jellyfish, which evolved more than 500 million years ago, have what might be called pain receptors that enable them to move away from noxious stimuli. Whether an organism “feels pain” is a somewhat different question, since a jellyfish doesn’t have a brain and doesn’t perceive pain the same way as we do. Whether fish feel pain is arguable, but in my opinion their nervous systems are sufficiently like our own that they probably do.
The most primitive surviving primates, the lemurs, have opposable thumbs and thus “hands.” The primate climbing style depends on grasping branches rather than using claws, so that claws probably evolved into nails about the same time as opposable thumbs developed.
Before there was either there was the cloaca, an all-purpose opening that served for both excretion and reproduction. When internal fertilization first developed, it may have involved just pressing the two cloacas together (as it does in modern birds). Eventually males developed penes to make the transfer of sperm more efficient. And yes, they always fit because if they didn’t the species would have become extinct. A true mammalian vagina didn’t develop until marsupials and placentals evolved, when the urinary and reproductive tract became separate in females.
That’s an ambiguous term, but by most definitions, would be difficult to determine from the fossil record.
How about something that would leave evidence: technology.
I think it’s pretty clear that no other species (except Neanderthals and similar early humans, if you don’t include them as our species) was sufficiently intelligent to leave evidence of technology.
Then the question becomes, why didn’t dinosaurs develop sufficient intelligence to have technology, given their long run?
The answer might be that given their various ecological niches, none improved their fitness by being more intelligent than they were. An increase in intelligence comes at a cost, and that cost is significant, in terms of energy expenditure. Quite possibly, dinosaurs would never have benefited as much from more intelligence than that extra intelligence cost them, so they never found themselves on a slippery slope where each additional increment in smarts gave them a payoff.
In addition, the smartest creatures tend to be mammals, which have a rather different brain organization than birds and reptiles, with a wrinkled cerebral cortex. It seems to be that among mammals, intelligence is boosted by increasing the area (rather than the volume) of this cortex (leading to the wrinkles). Possibly, the accident that allowed this development did not happen in the dinosaur line, purely from chance.
(Meanwhile, there are birds with much more intelligence than we’d guess, based on this oversimplistic “intelligence is proportional to area” hypothesis. For many years, scientists assume birds couldn’t be smart for this reason, and they turned out to be wrong for certain birds like parrots.)
Regardless, as mentioned above, there were dinosaurs that leave evidence that they probably had considerable intelligence, though probably not comparable to primates.
Also as alluded to above, human intelligence grew during a period where the environment was changing rapidly and frequently for a rather long period, which might not be the case for much of the reign of the dinosaurs. Perhaps intelligence provided flexibility to exploit newly emerging ecological niches, rather than to outsmart any specific prey or predators.
Mammals existed a LONG time – as long as the dinosaurs and longer – yet human-like intelligence only occurred within the last tiny bit of that time. Why didn’t mammals get intelligent earlier? (IIRC, the earliest mammals evolved about the same time as early dinosaurs, and outlasted them. However, they were marginalized during most of the dinosaurs’ reign.)
That’s a hotly debated issue.
In addition, there’s the dividing line between Oldowan and Mousterian stone toolkits, about 30K to 40Kya. The old kit was shared by different species and subspecies (Homo Habilis, Neanderthals, etc), was fairly simple, and was pretty much the same everywhere in the world. The new kit required more craftsmanship, had a wider array of more specialized tools, and varied significantly around the world. Some posit that the development of sophisticated language might have been the key here, allowing tool making to be more cultural than instinctive (glossing over a lot there, admittedly).
In Guns, Germs, and Steel, Jared Diamond points out that the Holocene (the last 10K years) is unusually stable, climactically, compared to the previous few million years. This might have been a crucial element in the development of agriculture.
These obvious demarcation lines are fascinating. Another one: when did we tame fire, and why? We have good evidence that we had fire 250Kya, and a pretty good argument that we probably didn’t 2Mya, but between those two, few data points (though there was one recently, which I can’t put my finger on.) Some posit that perhaps we lost our body hair when we started using fire routinely. There are other good hypotheses for that (walking upright in arid savannahs), but IMHO it’s possible there was more than one reason.
And the biggest one in my mind was, why did it take 3.5 billion years of life before the first eukaryote? I like Nick Lane’s hypothesis in “Power, Sex, and Suicide”, but no doubt there are a lot of other equally intriguing alternatives. But isn’t it funny that (as it seems) all the really fun stuff in evolution happened either very early on (nearly 4Bya) or else in the last 500My?
(Of course, there’s quite a bit of eukaryocentrism in that viewpoint, not to mention a dearth of good data for those first 3.5By!)
Colibri and others, please do me the honor of correcting any gaffes I may have made. I’m just a dilettante here. 
The near-simultaneous and independent origin of agriculture just after the end of the Pleistocene in widely separated areas that were not in contact with each other is an extremely interesting question. Agriculture started independently in the Near East (11,500 years ago), Mesoamerica (10,000 years ago), and New Guinea (10,000-7,000 years ago) and maybe a little later in South America (8,500 years ago). I think the most likely explanation for this convergence is climate change.
I’ll throw in Troodon, which had at least semi-opposable digits. And I accidentally ran across exactly such speculation:
[QUOTE=Wikipedia]
In 1982, Dale Russell, then curator of vertebrate fossils at the National Museum of Canada in Ottawa, conjectured a possible evolutionary path for Troodon, if it had not perished in the Cretaceous–Paleogene extinction event 65 million years ago, suggesting that it could have evolved into intelligent beings similar in body plan to humans. Over geologic time, Russell noted that there had been a steady increase in the encephalization quotient or EQ (the relative brain weight when compared to other species with the same body weight) among the dinosaurs. Russell had discovered the first Troodontid skull, and noted that, while its EQ was low compared to humans, it was six times higher than that of other dinosaurs. Russell suggested that if the trend in Troodon evolution had continued to the present, its brain case could by now measure 1,100 cm3; comparable to that of a human.[13]
Troodontids had semi-manipulative fingers, able to grasp and hold objects to a certain degree, and binocular vision.[13] Russell proposed that his “Dinosauroid”, like members of the troodontid family, would have had large eyes and three fingers on each hand, one of which would have been partially opposed. Russell also speculated that the “Dinosauroid” would have had a toothless beak. As with most modern reptiles (and birds), he conceived of its genitalia as internal. Russell speculated that it would have required a navel, as a placenta aids the development of a large brain case. However, it would not have possessed mammary glands, and would have fed its young, as some birds do, on regurgitated food. He speculated that its language would have sounded somewhat like bird song.[13][31]
However, Russell’s thought experiment has been met with criticism from other paleontologists since the 1980s, many of whom point out that his Dinosauroid is overly anthropomorphic. Gregory S. Paul (1988) and Thomas R. Holtz, Jr., consider it “suspiciously human” and Darren Naish has argued that a large-brained, highly intelligent troodontid would retain a more standard theropod body plan, with a horizontal posture and long tail, and would probably manipulate objects with the snout and feet in the manner of a bird, rather than with human-like “hands”.[31]
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More discussion here.
Considering how long it took for mammals to stumble into it, it might be that dinos would have gotten there if not for that pesky asteroid.
Two words: duck penis.
Slightly longer: if you look at it as an arms race, the vagina (cloaca) would have been first.
The point is a big brain (“check out the big brain on Brad…”) requires a lot of resources. One item I read said that 30% of our nutrients go to feed the brain. It’s also much more fragile in terms of susceptibility to lack of oxygen, damage, etc. As a result, unless it conveys an advantage, it’s a burden. Add to that warm-blooded metabolism, and the urgency to find food is increased. (Some debate to what extent the dinosaurs were warm-blooded).
As I mentioned, our singular lack of built-in weaponry has also contributed. A raptor with a dog-level smartness can still hunt and kill just fine. A bigger brain is just a burden until it starts producing. A cheetah does not need to be too smart, its superpower is speed, and it has claws. manipulating objects with snout and claws means there is no advantage in grasping - unlike the human advantage, where grasping means long point sticks and tool-making means offensive stand-off weapons like throwing stones, javelins, and archery.
Humans apparently statred off making longer and more daring forays out of the trees to collect food. Here running while holding things, and ability to judge the safety of the situatio were distinct survival traints that a higher-level predator did not need to develop.
Similarly dolphins or whales may be clever, even intelligent, but without the tool-making abilities (and maybe, more complex language leading to oral history?) where do they go from here? It seems to me the fact that whales did not learn to skedaddle at the first sign of a ship suggests they did not have useful vocabularies or conceptual thinking.
Looking at it from the perspective of the finish line, was it dumb luck or inveitable that we hit the correct sequence of circumstances that got us here?
Russell’s dinosauroid got a lot of publicity at the time, but I think it was absurdly anthropomorphic. Unlike ape bipedalism, dinosaur bipedalism depended on using a tail for balance, and the body was held horizontally. Russell’s model is basically just a human with scales and three fingers; it doesn’t resemble what a true intelligent dinosaur would look like.
A Sleestak!
It’s possible that the development of our intelligence past a dog-like or chimp-like level was due to runaway sexual selection. In early hominids, being a little smarter than average might have directly resulted in survival advantage, so they might have favored potential mates who were a little smarter. But then, once that tendency becomes established, you start seeing individuals who favor smarter mates just because smarter mates are favored by other individuals. It’s a positive feedback loop. As it happens, it kept up until it got to the point where greater intelligence is again a direct advantage, but it could also, given slightly different circumstances or worse luck, gotten to a point where we were too overspecialized for intelligence, and died off due to a deficiency in other areas, before our intelligence got to the point where we could make up for those other deficiencies.
But it seems women select for the opposite of smart?
Whereas men look for something else and overlook smart.
maybe you mean men and women have evolved smarts to game the system in each other’s mate selection.
No, I meant what it looked like: People being attracted to smart people. Yes, yes, you think people look for other traits instead… But would you be attracted to someone who was literally as dumb as a chimp? Do you know anyone who would be?
It was a pretty specific and unpredictable set of circumstances that led to our ancestors being the line that produced an intelligent set of descendants.
However, with millions of species and hundreds of millions of years, the raw likelihood that some creatures would have done it gets closer to 1.
You’re going to pitch a slowball like that right over the plate around here?
The comeback being - for a lifetime, or for the requisite eight minutes? 
Without our powerful brains, we’d be pretty defenseless relative to other species. We’re not particularly strong or fast. We’re thin-skinned with small canine teeth and clawless fingers. We don’t even have fur to protect us from bugs.
Intelligence is what gave our species a fighting chance for survival.
I wonder if this is what happened:
When the world was more climatically stable place and food was relatively easy to find, our ancestors did okay with just ape-level intelligence. Maybe they didn’t exactly flourish given their physical limitations, but they were able to crank out enough kids to keep the species going from generation to generation.
Then something happened. The world began to change radically. Droughts made food scarce; weather became extreme. Humans who lacked the ability to improvise and think beyond instinctual habit were not able to adapt and soon died. But those humans whose brains were not as anchored to instinctual behavior, maybe because of some genetic quirk, were able to adapt to change. Maybe they were more willing to explore novel food sources. Maybe they were more attuned to cause and effect, so they were actually able to learn through trial and error while others were not. Maybe a changing world helped select for smarter humans.
A changing world may have also promoted natural selection in other animals, too. Just not in the way we experienced.
Compared to other species, we do seem to rely less on instinct to tell how we’re supposed to live. Could this be because, at one time in our history, being driven by instinct carried costs to evolutionary fitness?