I personally think
They have served whatever purpose they were meant to serve and were on their way out (or to retirement in the form of birdies). They were only nuked from orbit as a precaution, because that's the only way to be sure, you know...
The dinosaurs would have survived the asteroid that smashed into Earth and wiped them all out had it not been for the rather poor – from their point of view – timing with which it arrived. The demise of these scaly – or indeed, even feathery – overlords may not have happened if the space rock hit a few million years later or …
"In the period before the strike, dinosaurs were more diverse and the food chains were more robust, the researchers found, whereas if they had survived for a few million years more, more species would have evolved, perhaps making them more resilient to the conditions after the impact."
Evolution cannot plan. Simple as. To assume that the diversity will fill a specific range, is a big assumption. It's like assuming no deserts exist on earth. Some places no rain falls, some gaps in diversity are not filled...
More than that: the pattern of dinosaur evolution leads me to suspect that there is a natural tendency, within evolution, towards more 'fragile' ecosystems. "Robustness" means redundancy, redundancy is inherently wasteful, therefore a more robust ecosystem will be out-evolved by a more fragile one.
So if the meteor had struck later, the situation would likely have grown worse, not better. And maybe we wouldn't be here today.
My thought is that this is around the time that grass evolved. It would have been outcompeting the shrubs and ferns that predominated the food chain and would have caused major changes in the fauna that fed on it. This could only have continued with more time and put large pressures on the dinosaur populations. It is likely they would have (mostly) gone extinct anyway. The meteor just ruled a line under them.
The research doesn't seem to harp on this "unlucky tiing" thing. I suspect the media have deliberately read that in to get a new angle. Some interesting observations in the work, for example challenging the old theory that dinosaurs were in decline prior to the impact. The authors have rightly drawn attention to the gaps in the evidence. For example, they observe that freshwater species fared better than land based or marine but speculate relatively little on why that's so.
Which begs the question, "is it reasonable to expect any meaning from randomness?"
If not, everything you see and think and feel is purely a function of the random which came before it.
You and the rock at the bottom of the garden are as important as each other.
Now we know why politicians act as they do.
The "Silurians" are tucked away in various hiding places in suspended animation, waiting for conditions on Earth to recover from the disaster which they predicted. There was also at least one "Silurian space ark" carrying dinosaurs to another planet. Doctor Who has had a few difficult encounters with them, so it must be true.
Long ago, I was walking the most adorable girl to her front door. The walking was painful and difficult, great problems with where to keep my hands. At the door, this most adorable creature, asked me if I had any of "those". And when I replied "what those" she slammed the door agaist my "the one for those". Waking home, in less pain, I relized I had lots and lots of "those".
Dear ElReg, considering the increasing amount of people who are loosing their faith in boffins. Please leave those "If Boffins" out. Seriously, if there was no sun, no moon, no oxygen etc.
Besides it was not "The dinosaurs that were victims of colossal bad luck." it was me.
If a massive super-volcano in Siberia/the Deccan/Jellystone Park were reasonably close to letting go (within a few million years), wouldn't a massive asteroid strike (even on the other side of the planet) be the sort of thing that could trigger it? I've wondered for a while whether the "it was an asteroid", "no, it was a super-volcano" argument about mass extinctions was a true dichotomy.
Well.. The KT border tells us there must have been something that is rich in stuff the earth has not in sufficient quantities to show up all over the globe that "arrived" at that time. Currently nothing else but "a bloody big rock hitting the earth at interplanetary speed" fits that bill. It also helps they've located the impact site nowadays.
Outside of the obvious effects at ground zero and its direct surroundings (total annihilation of just about everything), the shockwave that propagated through the globe would almost certainly have triggered every fault and subcritical volcano then extant, adding some local spice to the mix. Note that the volcano would have to have been suvcritical to begin with. The ones with empty magma chambers would at most have collapsed. New volcanoes... well shaking the globe up like that would have most likely opened up a crack or two.
The problem with the supervolcanoes is about the same as with "ordinary" volcanoes: would they have been subcritical at the time? The Siberia traps, being at the opposite end of the globe at the time, belong to a much earlier event, and would have been "dead" up until the impact. Would the converging schockwave have cracked open the surface there, forcing eruptions? Most likely. Would it have blown up supervolcano style? Not very likely.. The engine there was already running idle.
The Deccan traps are from that era, and its existence may well be tied to the impact itself. The problem with trap-like features is that in and of themselves they are not strong enough to force a global mass extinction. The changes they're forcing are too gradual, so that taxa (not species...) have time to adapt to the changing environment. They are very unlikely to cause a shift in the dominant taxa, certainly not in the relatively short period of the KT extinction. The Deccan would, however, have added insult to injury, certainly locally.
Yellowstone, if the plume that feeds it was already present, and in more or less the same absolute place, would have been well under water, between the two parts of what now is the north american continent. Currently that spot would be somewhere scrunched up in the Rockies... Good luck hunting for it... ;)
Besides... the dinosaurs *did* survive... look a healthy old-fashioned rooster in the eye.. imagine it to be man-sized... and remember that chickens are omnivorous... The old "reptilian megafauna" may have gone the way of the mammoth, that doesn't mean their cousins aren't still around..
Well, the Deccan traps were already acting up, but the Yucatan impact probably punched it into overdrive. What's more, the impact likely dislodged a few methane clathrates which lead to some additional oceanic die-off, and caused the climate to yo-yo around for some time, ringing like a bell until it stabilized. In all, the Yucatan impact event could hardly have happened at a worse time. There was such a convergence of miserable events, it's kind of amazing so many major strains survives.
Crocodilians, Amphibians, Lizards, Birds, Mammals and a lot of water-based life all made it through. But land and ocean fauna above a certain size didn't...and a lot of different types of plants were simply wiped out. The K-T event was huge. Not nearly as huge as the P-T extinction or the current anthopocene extinction, but still very much a major extinction event.
If we were around then, we would not have survived. Nothing our size would have. And that's worth pondering for those who believe space exploration is a waste of time.
Dinos had no souls, so luckily for them they didn't need 'saving' from that lovely notion of eternal agony in hell, or worse, eternity rubbing shoulders with the Abrahamic God and his constellation of hangers-on.
I often wondered which was the first creature evolved enough from their ancestor to be deemed human enough for the soul to magically appear (and even more magically, need saving from Hades).
Or perhaps if we look back through our collective family tree there will be a few thousand generations where a teeny weeny precursor soul started to develop, needing at first 'a little help to avoid a mild burning', but after a few more generations getting larger and more generally need in help of general salvation. What evidence there is suggest that humanity was deemed 'human enough' was when Scandinavians evolved, as that appears to be the chosen form of our Lord of Creation in most of what gets stuck through our letterbox by the Jehovah's witnesses.
P.S. See why creationism is the only true way to deal with evolution? Far easier to just stick your fingers in your ears and go 'LA LA LA' than try to square science with an idiotic celestial salvation bureaucracy.
The earth is at another vulnerable point right now. Time to look for another big rock...
Perhaps our ancient "Cretaceous Poultry™" will have it's revenge? Revenge is a dish best served cold...like the cold blooded reptiles(or is that over-sized chickens?) of the past.
Then in another 100 million years 8 foot tall intelligent roaches will be contemplating their ancient past oblivious of the ones that called themselves "humans"...
"Perhaps our ancient "Cretaceous Poultry™" will have it's revenge? Revenge is a dish best served cold...like the cold blooded reptiles(or is that over-sized chickens?) of the past."
You better pray, then, that:
1) They are gourmets
2) The world heating is true.
Then, and only then, we would be safe - as the dish would be hot...
A more important question might be "why didn't the human beings survive <disaster X>"
If, today, you can manage to determine what <disater X> will be, you might have a chance of being part of the lucky few ( Lucky being a very subjective word)
You will then be in a favourable position for answering your initial question.
A) Dinosaurs were not cold blooded
B) They didn't get wiped out. Avian dinosaurs survived. (Small ones, mostly).
C) Some large animals (crocodilians) survived.
Why did the dinosaurs die out? Size, mostly. But also that they needed to eat rather a lot, and on a regular basis. Crocodiles, for example, don't eat much and they can survive off carrion for a long, long time. That's why they survived. Small avian dinosaurs and small mammals probably survived for the same reason. A combination of being omnivorous, small and able to live off carrion. Wide global distribution helps too.
Most mammals (individuals) and mammal species, as well as avians and avian species probably died off. But there were so bloody many of them in so many diverse little niches that they basically could live off the dead and dying for generations. At least until plants started to grow again and the planet began the very long, slow, miserable path towards healing.
I wonder what major species groups will make it through the anthropocene?
I don't know about that. You make the rather large assumption that humans will make it out of the anthropocene. I see no reason to assume this.
Mass extinctions generally end up totally disrupting the ecosphere. Ecosystems suffer right down to the primary producers (and pollinators!) which ultimately ends up with the collapse of higher order food webs. We have no way of knowing if humans will survive that. At our current level of technology we would not. Will we develop the ability to survive without pollinators, let alone other primary and secondary producers?
If we can't survive, why would any of our dependent species do so? Even if we do survive, will there be enough scraps for the birds (or the bees?) That's before we start assessing the kind of damage currently occurring to the oceans. If the oceans go, we've had it.
So I think it's a crapshoot. We don't have enough data to know how it's all going to play out for our species, let alone any of the others. Hopefully some will make it. I'd like to think Earth has one more shot at sentient life before it moves too far our of the habitable zone. (500M years, give or take.)
We, the descendants of the hermit crab, and overlords of Planet RockPool (or 'Earth' to you) do ponder on the irony of now-extinct mammals from the past discussing the demise of the previous overlords whilst in the middle of the events that founded their own extinction and gave the planet to our (admittedly quite stupid) ancestors (though nothing that couldn't be fixed by a couple of hundred thousand generations and finally ditching the idiocy of looking for shells to live in!)
Transmission over. The wormhole closes.
If the food chain were precarious, then a meteor is only one option to topple the dinosaurs. It doesn't sound like luck to me.
See "Foundation", Asimov, (and even "The End of Eternity") for theories of things taking their course in spite of perturbations. In that sense, perhaps the end of the dinosaurs was inevitable.
...is just how hard it is to get your brain around Deep Time and probability. Because in truth the conclusion is about as surprising as being told that water is wet.
What is easy to overlook is just how immense Deep Time is. Set against that, and given that the possibility that the dinosaurs as a whole could be wiped out at any particular point was always small, but also always greater than zero, the probability that they would be wiped out by *something*, *sometime* was always 100%. The only question was how long it would take, and whether whatever it was would wipe out life on the planet entirely. And more to the point, it was always likely to take some form of rare, extreme catastrophe to give the final push - because life is *good* at surviving, and simply works around anything less.
In the end, it took getting on for 17 *million* years for the something to happen; and life here, as a whole, survived. The truly big surprise, if there is one, ought to be not that the dinosaurs eventually died out through "bad luck", but that it took so long for that to happen.
I think I saw a documentary about the dinosaur extinction earlier this summer that said the dinos weren't wiped out by an asteroid, but rather were turned into some sort of metal by extra-terrestrials. We are apparently using that metal now to build mechanical devices and shape-shifting robots. It's all very scientific and high-tech. The documentary was horribly filmed, the narration was awful, and the re-enactments were second rate, but overall, it did provide a glimpse into the death of the dinosaurs. And it seems that one of the shape-shifting robots has been sent on a deep-space mission to find the "creators". Not sure what that's all about, but there you go.
On this morning's Today programme, John Humphrys introduced the topic by reflecting that had things fallen out differently "the dinosaurs would still be with us today".
Made me chuckle, anyway. Reminds me of the carnival manager's comment about the "Lion and the Lamb" exhibit - "they get along just fine, but the lamb needs to be replaced pretty frequently". If the dinosaurs hadn't died out, our ancestors MIGHT have survived by hiding in the very tops of the biggest trees. But probably flying dinosaurs would have munched them even there. The idea that they would ever have come DOWN from the trees to hunt... well, it's just side-splitting.
"The idea that they would ever have come DOWN from the trees to hunt... well, it's just side-splitting."
Why? Dinosaurs were stupid. Hell, chickens have several million years worth of evolution on them. Being large and vicious doesn't mean nearly so much as being clever.
Lions, tigers and bears - oh my! - didn't stop us. Why would dinosaurs have? Do remember that the really scary stuff - gigantasaurus and so forth - lived in a world with massively different temperatures and atmospheric oxygen content.
Dinos lives in a world of much higher free oxygen. Most wouldn't be able to breathe in our atmosphere. So yeah, we'd have to deal with some truly terrifying things...but they're all more or less like what we've had to deal with already.
Our ancestors faces down dire wolves and saber-toothed cats, dined on mammoth and fought terror birds. While I, personally, wouldn't want to face an angry velociraptor or a pack of compys, that doesn't mean at all that we wouldn't have been able to take the bastards, if they'd made it.
Of the dinosaurs that could have survived to today more or less unchanged, I doubt there are any that would have truly threatened our extinction.
Hell, chickens have several million years worth of evolution....
Evolution doesn't necessarily mean becoming more intelligent. Remember that evolution doesn't really have a goal, so any change which promotes survival and reproduction will stick. The movie Idiocracy pretty well laid out an example of how evolution could diminish human intelligence. It was taken to the extreme, but the scenario is realistic.
In animals I could see several scenarios where the most intelligent members of the species don't last long. Perhaps the most realistic is a situation where a given species survival is so mind-numbingly easy that they don't need intelligence, in which case natural selection would get rid of it. Chickens are a pretty good example. A smart chicken might find a way to escape the farm, and that chicken, as a member of the bottom rung of the food chain severely lacking in any means of hiding and only having a relatively weak means of defending itself, would be doomed.
Could a smart dinosaur have existed? Maybe. But no matter how much Hollywood puts "idiocracy" into a movie, evolution doesn't work like that, and it doesn't work anywhere near that fast.
Psittacopasserae - Songbirds, Parrots, Corvids and the like - are pretty smart. But Cariamae - not to far off the evolutionary tree from Psittacopasserae are pretty mediocre, at least by mammalian standards.
Go on up to a side branch of Telluraves and look at families like Strigiformes (owls) and Piciformes (woodpeckers) and they're nowhere near as bright as Corvids. They're about as bright as Cariamae.
This means that the extreme high intelligence seen in Corvids and Parrots is probably restricted to Psittacopasserae. (Let's save arguments about Falconidae for later, hmm?)
Go all the way up the tree to Neoaves and look at Galloanserae (chickens and other waterfoul) and they're dumb as posts. With the sole exception of Columbiformes (pigeons), pretty much everything under Neoaves are dumb as posts, and the Ratites - which are up a bit from Neoaves are just as dumb.
Now, this says to me one of two things happened: Pigeons evolved intelligence separately from Psittacopasserae, or intelligence evolved prior to Ratites, and virtually every bird family since birds began evolved to be dumb except Pigeons, Parrots and Corvids.
So we start looking at Pigeons versus Corvids. Long story short: Pigeons are nearly as smart as Corvids overall, but they are good at completely different tasks. Parrots, OTOH, aren't quite as smart as Crows, but are generally proficient in the same sorts of tasks.
This says that it's really likely Pigeons evolved intelligence separately from Parrots/Corvids, and that Parrots and Corvids likely shared a common "smart" ancestor. (With Corvids evolving more towards intelligence than Parrots in the same time.)
So if dinosaurs were smart, where did that smart go? It didn't seem to make it into birds. It's possible that non-avian dinosaurs were smart...but when we start looking for signs of advanced brain structures in their skulls - for whatever little that's worth - we don't find them. No evidence of higher complexity, or any species of non-avian dinosaur with even an avian EQ, let alone a mammalian one.
So I honestly don't think it's very likely that "dinosaurs were smart, then evolved into dumb." Evolving to be less bright can - and usually does - come with "evolving to be small". Smaller animal = smaller brain. There are exceptions - Modern Humans, Corvids, Proboscidea, etc - but as a general rule "smaller brain = dumber". This is where looking for special brain structures comes in, as they could indicate intelligence in smaller brained animals.
Most dinos weren't huge. We're pretty sure that the huge dinos tended to have brains that were actually less massive than their spinal columns. So where does that leave us? Potentially a freak family here or there that evolved intelligence then snuffed it rather quick? Possible.
But how likely do you really think it is, given the evidence, that said smart dinos even existed, let alone devolved over time. Idocracy takes millions of years, and usually leaves a fossil trace.
It was widely accepted a decade or two ago that the Yucatan impact was just the 'final straw', as the global environment was fairly sick due to large scale persistent volcanism. Nice to see Edinburgh University catching up, should get up-to-date in the next few decades at this rate. Watch this space for 'Birds Evolved From Theropods' breaking headline in a decade or two.
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