Before the Dinosaurs became extinct due to some arguable catastrophic effect they roamed our planet for some 100 million years. Yet only 65 million years has passed since that time and the earth has evolved a highly intelligent species (Homo sapiens sapiens).
Now I realize that evolution is not a gradual progression, but after 100 million years why were the dinosaurs still so incredibly primitive from an evolutionary standpoint?
Primitive? why do you say that?
I would imagine it’s because Humans evolved from mammals which were in existance at the same time as Dinosaurs and therefore humans have been evolving for 165 years
Sorry! Make that 165 million years…
Primitive? what makes you say that?
I hate doing this, but:
prim·i·tive Pronunciation Key (prm-tv)
adj.
1 Not derived from something else; primary or basic.
2 Of or relating to an earliest or original stage or state; primeval.
Being little evolved from an early ancestral type.
3 Characterized by simplicity or crudity; unsophisticated: primitive weapons. See Synonyms at rude.
I assume that you’re using ‘primitive’ in the sense of definition 3? (just a request for clarification, nothing more), if so, I repeat, What makes you say that?
Sorry, preview posted there.
Primitive as in being lower-order animals intelligence-wise. I’m speaking primitive in the same way that fish and snakes and other simple mammals are. Not possesing higher degrees of intelligence.
Dinosaurs were basically, stupid, instinct driven animals, unless you want to count the conjecture about species like Velociprator hunting for sport.
Primitive in the sense they never showed higher order thinking seen in primates.
To Dazguy: And unless you count the Flintstones, mammals never coexisted with Dinosaurs.
Before the catastrophe, the dinosaurs had things relatively easy. They didn’t need to evolve high intelligence, because their environment was such that their needs were met purely by the extremely complex physical evolution that they underwent. Certainly there would have been some dinosaurs that were more intellectually able than others, but their environment didn’t warrant them getting smart. Furthermore their physiology was probably such that the niche filled by mammals wasn’t necessary from that particular class of animal. If you’re 20 feet tall and can kill pretty much everything in your path, you don’t really need that much subtlety.
BYW Eidolon, you’re wrong:
Try not to think about it like
Dinosaurs
X killed everything (i think it was an almost sudden shift in magnetic field)
New animals
Its like we share the same ancestors with dinosaurs - but at that particular time we scratching ourselves and bumping into things.
The dinosaurs (sorry to generalise) were far more " advanced" -biologically- then we were - i shudder to think at the level of technology they would have today if they had not been turned into birds.
Maybe a naturalist like Darwin’s Finch will be along soon to explain this properly, but I think you’re making a mistake in assuming that evolution is a linear path of improvement, and that something about the dinosaurs impeded their progress along this path - that isn’t the case. Evolution just provides a mechanism for adaptation to under-exploited niches, and there are lots of ways in which an organism can fit well to its environment (“more intelligent” isn’t necessarily “better”). The dinosaurs were biologically successful without having large brains, so they didn’t develop large brains.
The development of homo sapiens is itself an unprecedented case and doesn’t provide a model for how evolution works more generally.
The link jjimm posted isn’t a unique case either - there were plenty of mammals around in Cretaceous times but they tended to be inconspicuous.
Short Answer:
We got lucky
Long Answer:
I think this is an issue of probability. What you’re really asking is what is the probability that intelligent life will evolve in any given amount of time. From that you hope to understand why the mammals got lucky whereas the dinosaurs didn’t. Nor did the other largemass animals like birds, reptiles and fish.
We live on a planet where the probability of intelligent life having evolved is 100% because we’re already here. But that’s only looking at the last few million years. The previous 2,500 to 3,000 million years of evolution suggest that the probability of intelligent life evolving is small, even smaller when you spread it across the 6 to 8 billion years in which a planet might hope to evolve intelligent life. This 100% is skewing your perception of how probably the evolution of intelligent life is.
The problem is we have very few planets we can effectively study to find out how probable it is that intelligent life will evolve. Scientists have tried to estimate this and probably the easiest collection of guesses you’ll find is under the “Drake Equation” although those might trend towards optimistic guesses. So that’s what we have guesses. Perhaps some intelligent guesses but guesses none the less.
Not hard data For Earth we could say that intelligent life was never more then 5 million years away for any time in the past 360 million years (ever since the first land vertebrate). We could then say that for any given 5 million year period there was a 1 in 72 chance that intelligent life would evolve. Since Dinosaurs were around for 160 million years there was a 4 in 9 chance that intelligent life would have evolved during that period. It just didn’t happen to them. Those lucky set of circumstances that would lead to HIL never came about.
The problem with all of the above is the error bars. Our statistical sample of 1, actually less then one since we don’t know what would have happened on Earth in the next 4 billion years if we hadn’t evolved, must yield error bars which must be huge.
Firstly, that theory is generally discredited, so you’re going to have to provide a cite to back it up.
Secondly, the idea that the dinosaurs would have developed any technology whatsoever is ridiculous. The OP has already pointed out that dinosaurs lasted perfectly well for hundreds of millions of years without developing the physiology we’d associate with intelligent behaviour (and I’ve already pointed out that evolution is not linear progression).
Thirdly, your English is so bad that it’s difficult to take you seriously anyway. Please don’t take that as a personal attack, and I apologise in advance if it’s not your first language.
Mammals evolved before dinosaurs, back before the Triassic period. Or rather animals with a large collection of mammal like features but may not be true mammals in the modern sense existed in the Permian age before dinosaurs evolved. After the Permian extinctions, the field was open for various groups to exploit a whole series of ecological niches. For whatever reason (I like Bakker’s theory in The Dinosaur Heresies), the dinosaurs had, by the end of the Triassic, out-competed every other group and were the dominant type of organism on land. Other groups exploited the seas (e.g. ichthyosaurs, plesiosaurs), the air (e.g. pterodactyls, which may be closely related to dinosaurs) and niches for small, nocturnal creatures (e.g. mammals).
After the Cretaceous mass extinction, mammals stepped out of the shadows and tried to fill the dinosaurs’ boots. One particular group, retaining a quite primitive morphology (compared to, say, a sheep), took to the trees and evolved high intelligence as its key adaptation. We are in that group of organisms.
Osiris, nice theory. Very sound. I like it. Shame about the lack of evidence but, given the sample size, as good a theory as many that have no doubt earned some people PhDs. My only caveat would be to say that intelligent life was never more than 5 million years away since warm blooded land vertebrates evolved (energy costs of large brains), which may reduce the period to the last 180 to 200 million years.
Evolution does not necessarily need to work towards an eventual intelligent species. Intelligence only came to rule when it became a key factor in natural selection(thats only for this few million years of our ancestry). Some pretty “brainless” creatures still can survive evolutionarily by reproducing quickly. Take the cockroach for example, it hasen’t changed much since before the dinosaurs and its still thriving under an intelligent specie’s constant butchery.
splut…ah, got another one 
Sure, so are sharks and box jellyfish even more so; even lions and bears probably couldn’t write Database applications as well as me, or even read a book, dumb animals, but how would I fare against them in their element?
Intelligence isn’t the only survival trait or even the best one; look at bacteria such as MRSA, which has beaten many of our intelligently-formulated antibiotics.
Evolution has no ultimate goal; ‘whatever works’ survives, ‘whatever happens to work better’ is more likely to survive.
Every now and again I get into an argument with my boss "look at the giraffe’ he says, “can there possibly be a better refutation of evolution - look how ungainly and unsuited to survival it is, how can that be the result of ‘survival of the fittest’?”
The point that he is missing entirely is that if giraffes were not suited to survival, there wouldn’t be any giraffes.
As far as I can tell, the only survival trait the dinosaurs lacked was the ability to survive the catastrophic conditions arising from a major asteroid strike; we, despite all our intelligence, may fare no better.
Thanks Go. It’s ironic that taking those arguements and limited data it follows that the more optimistic you are about the ability of intelligent life to evolve from primitive life the lower the probability that intelligent life could evolve in any given time span becomes. I would say your limit makes a little more sense. Although I suppose warmer athmosphere and higher oxygen content might have overcome cold bloodedness, but I really don’t have the education to argue that point.
Does anybody know if dinoaurs had an incomplete 4 chambered heart. I knows reptiles have it where the oxygenated blood from there lungs mixes somewhat with the depleted blood from their body before being pumped out into the body. I remember hearing some sort of arguement over whether dinosaurs had the same thing awhile ago. I know at least one dinosaur heart has been discovered. That would certainly put a constraint on their evolution.
Dinosaurs never became intelligent for the same reasons that there are no flying snails: A combination of legacy evolutionary traits that didn’t provide them with an easy path to evolve the necessary equipment, and the fact that the survival requirements of their environment didn’t require evolution of those particular features for those creatures to survive well. The costs of evolving greater intelligence outweighed the benifits of doing so.
I’d also like to point out that although dinosaurs evolved for a hundred million years without achieving higher intelligence, fish have been at it for a lot longer, and you see how far they’ve come.
They are pretty damn good at being fish, though.
I hear they do well coding Roaracle…
OK, I’ll go away now…
Zev Steinhardt
Yep. Mammals are OLDER than dinosaurs. Everybody knows about the Cretaceous mass extinction that wiped out the dinosaurs and left an empty ecosystem for mammals to step into. But nobody knows about the Permian mass extinction that wiped out the mammal-like reptiles and left an empty ecosystem for dinosaurs to step into.
Ah the irony…