Did Insects Kill the Dinosaurs? 184
Ponca City, We Love You writes "Asteroid impacts, massive volcanic flows, and now biting, disease-carrying insects have been put forward as an important contributor to the demise of the dinosaurs. In the Late Cretaceous the world was covered with warm-temperate to tropical areas that swarmed with blood-sucking insects. A theory explored by researchers at Oregon State suggests these bugs carried leishmania, malaria, intestinal parasites, arboviruses and other pathogens. Repeated epidemics may have slowly-but-surely worn down dinosaur populations while ticks, mites, lice and biting flies tormented and weakened them. 'After many millions of years of evolution, mammals, birds and reptiles have evolved some resistance to these diseases,' says Researcher George Poinar. 'But back in the Cretaceous, these diseases were new and invasive, and vertebrates had little or no natural or acquired immunity to them.' The confluence of new insect-spread diseases, loss of traditional food sources, and competition for plants by insect pests could all have provided a lingering, debilitating condition that dinosaurs were ultimately unable to overcome."
Mosquitos (Score:5, Funny)
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Seems odd (Score:4, Insightful)
They were new? I am by no means an authority on the subject, but from what I remember learning about evolution, one-celled-organisms came along before cell colonies. Further, small cell colonies (bugs and such) came around before big ones (dinosaurs and such). I even recall learning that the first self-replicating DNA strands were much more virus-like than bacteria-like...since the whole membrane and organelle system didn't come about until a bit later.
So, by the time the dinosaurs were around, the world should have already been densely populated with viruses, bacteria, and small bugs which could find the guts of a dinosaur to be fertile breeding grounds.
I really don't see how these things, and the diseases they cause, could have come around after the fact. Maybe some more sinister versions of them, more specifically targeted at the dinosaurs of the day, came around after the fact, but I don't think that alone would account for a mass extinction.
If you have corrections to offer, don't hold back (not that you would).
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They were not claiming that these diseases did not exist until this time. They are saying that the diseases adapted to insects and used the insects as carrying agents at far back as the cretaceous period, maybe longer.
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In fact, since insects had been *The* animal ecosystem on land for millions of years before the first vertebrates skulked out of the ocean, it's pretty plausible that all manner of mites and parasites had existed and passed around proto-diseases--lets not forget that even today, our insects are covered with even tinier insect parasites. Parasites of all sorts also existed in the oceans where the vertebrates were evolving. Parallel evolution makes much, much more sense.
Insects (Score:3, Interesting)
The vast majority of flowers are intended to attract insects. Think about the most notorious disease-sp
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Simpsons (Score:2)
Wasn't that a Simpsons Halloween episode a few years ago?
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http://www.bio.utexas.edu/grad/krushnamegh/Moorings/PhotographyOtherAnimals/pages/Trombiculoid%20mites_jpg.htm [utexas.edu]
http://www.tvrhl.com/Photos/pages/Mites_jpg.htm [tvrhl.com]
extremely suspect (Score:2, Redundant)
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Re:extremely suspect (Score:5, Interesting)
In short, it is unlikely that biting insects could be responsible for all this chaos. The extinction was simultaneous, worldwide, and (in geological terms) instantaneous, it hit animals and plants, and it hit organisms on land and in the sea. Now, it turns out, probably not coincidentally, that at the same time all of this happens, a huge asteroid or comet impact- one of the biggest in the past half-billion years- takes place in the Yucatan, blasting dust into the stratosphere, sending tidal waves across Texas, and probably igniting much of North America in the process. An asteroid impact is probably capable of causing an extinction like this. Its doubtful that gnats, mites, and mosquitos could.
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Re:extremely suspect (Score:5, Informative)
Sharks are sharks, Ceolocanths are fish, and Aligators are reptiles. Although all three forms date back very nearly how they look now to the time of the dinosaurs, it would be an equivocation to call them "dinosaurs" when discussing the "extinction of the dinoasurs".
Apologies for spelling, mine is pretty poor.
Re:extremely suspect (Score:5, Informative)
Triceratops wasn't a sauropod. Like other marginocephalians, it was a member of one of three orithischian (bird hipped) groups (the other two are threophora which includes armoured dinosaurs such as ankylosaurus and stegosaurus, and ornithopods such as the hadrosaurs). Sauropods were saurischian (lizard hipped), and are therefore more closely related to therapods than either are to the ornithischians.
Re:extremely suspect (Score:4, Funny)
Ow...that post hurt my head. Someone left the door unlocked and a paleontologist got in!!??
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Doesn't he know that Slashdot is only for armchair experts, not actual ones?
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Thanks for the post, BTW. I was obsessed with dinosaurs for a few years when I was a kid, but haven't dug into them in any depth since then... this kind of discussion churns up memories of sitting in a dim corner of the library, poring over books that were way over my head.
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This pretty much describes me, although the interest in extinct life forms rather than dinosaurs in particular has stayed with me (it is not however my profession). It's interesting to note that there have been several mass extinctions throughout the Earth's his
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But as for the fascination with the Cretaceous mass extinction -- I think it comes directly from our fascination with dinosaurs... the enormous and toothy types scare the bejesus out of us, to put it one way, and it's perhaps even more awe-inspiring to think of them all being wiped out than it is to imagine them alive. And from
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Or it could well have been due to some factor or combination of factors that we don't know about because they don't leave any physical records that we've been able to detect (and we may never be able to detect them without some form of time travel). The way that various new fossil discoveries have caused radical reviews of man
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I don't think, strictly speaking, that the above are considered 'dinosaurs'.
I think all but crocs actually predate dinos -- I'm not sure about the crocs. We're talkiing old critters here -- from an evolutionary perspective, that's some staying power! Over 450 mya and counting!
Cheers
Re:extremely suspect (Score:4, Insightful)
Same old error, again and again. (Score:2)
Why can't people understand, birds are the dinosaurs that survived.
Birds relate to dinosaurs as bats relate to mammals. Or, birds relate to dinosaurs as butterflies relate to insects. It is as simple as that.
That, unread, article must be bad.
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Sorry, but that was an example of the common misconception I was trying to point out. Contrary to your proposal, birds _are_ a group of species of dinosaurs.
If all mammals, except the bats for example, went extinct, your favorite bat would not seize or stop being a mammal. And the number of very specific adaptations of the bats would NOT set them apart (sonar, leathery wings, wrinkled noses, large ears,
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If all mammals, except the bats for example, went extinct, your favorite bat would not seize or stop being a mammal. And the number of very specific adaptations of the bats would NOT set them apart (sonar, leathery wings, wrinkled noses, large ears, etc). The bats would remain inside the mammal group, just as all the bird species remain inside the dinosaurs. Bats are specialized mammals and birds are specialized dinosaurs.
By that argument, humans are specialized fish. At some point, you have to say a line of descent has left the bounds of the definition.
Humans as specialized fish (Score:2)
I object (Score:2)
Modern classification, however, does it in a consistent manner, except for a few die hard scientists from fifty years ago. They still think birds are "sufficiently different" to warrant a separate category, with a rank higher(!) than dinosaurs. There are even thick books on the subject.
Some early authors even argued that humans should be placed not among apes or mammals, or even animals, but in a Kingdom on its own - Psyche...
The similari
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For example, "trees" or "bushes" has no connotation of ancestry beyond they are all plants. Still, ancestry is the only criterion one is striving for in the classification today, and the "truth" stri
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Or by "resistance" do you mean "habits of cleanliness and antibiotics?"
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No links because I'm about to head off and got this from dead trees anyway, but DNA analysis indicates that human diversity in W Europe dropped dramatically around the time of the plagues and that a mutation arose conferring some resistance. Just like Sickle-Cell Anaemia, only a fraction of people have it.
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The "sickle-cell" malformation of red blood cells occurs when someone gets the trait from both mother and father. If you have the sickle-cell trait on one chromosome, you get resistance to malaria without developing sickle-cell anemia, and that is a much better result for the individual. It sucks when you get two copies of the gene, but having that resistance in the population is worth it, from a purely statistical (and thus evolution
No wonder they're all dead (Score:2, Funny)
and all within the past 6000 years...
the first lawyer was probably the deathknell.
Uh... all of the above (Score:5, Funny)
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Butterflies, specifically (Score:4, Funny)
http://en.wikiquote.org/wiki/Mystery_Science_Theater_3000#Future_War [wikiquote.org]
Thank you for not killing me.
MalaRIAA (Score:5, Funny)
Is this another Music Industry article?
I don't buy it (Score:2)
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Parasites didn't materialize from nowhere (Score:2)
What nixes this idea for me is that the microbes didn't grow on Mars and suddenly rain on the dinosaurs out of the blue. Microbes and reptiles all had to grow up together.
Bernard Werber (Score:4, Interesting)
But frankly, I don't think new diseases would wipe out an entire order of life, all over the world, in all ecological niches, without wiping out other unrelated orders of life. In their hundreds of millions of years of existence, dinos had to fight off insects and diseases that were there before them, it couldn't just wipe them (and just them) off the face of the Earth in such a short time.
Hold the phone (Score:2)
'After many millions of years of evolution, mammals, birds and reptiles have evolved some resistance to these diseases,' says Researcher George Poinar. 'But back in the Cretaceous, these diseases were new and invasive, and vertebrates had little or no natural or acquired immunity to them.'
Uh, exactly why would mammals have some natural resistance to these diseases such that they would survive better than the dinosaurs? Especially considering that some mammals (e.g., humans) don't have resistance to Mala
Re:Hold the phone (Score:4, Interesting)
And yes, there are a number of genes that code for malaria resistance in human beings; they exist wherever malaria is common. The most well known (and most common?) is the sickle cell gene. But there are a number of other mechanisms that have evolved independently that protect people from malaria. If your ancestors had a lot of trouble with malaria, you are probably much more resistant to it than someone whose ancestors came from Norway.
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First of all, I'm not a paleontologist.
But here are a couple ways that seem plausible:
Lets assume larger animals usually have much longer life cycles. If animals accumulate parasitic infections over it's life cycle at the same rate, then the smaller mammals with their shorter life cycle w
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Far from all dinosaurs were large though. Some species were no bigger than turkeys, and probably had a similar generational cycle.
"This might also help explain why smaller dinosaurs seemed to have lived on and were able to eventually evolve into birds."
Dinosaurs diverged from birds around a hundred million years before the dinosaurs themselves became extinct.
"It's also possible that mammals biology was different enough than dinosaurs that mos
poor understanding of evolution and parasites (Score:4, Insightful)
they gradually evolve in tandem with their hosts, and they make sure they always leach off the host's resources, and never kill their host
a parasite is not interested in killing its host. because then the parasite dies too
and a parasite is evolved to infect its host very carefully and specifically. dinosaurs did not suddenly get worms that no other creature ever got before. the worms evolved as the dinosaurs evolved
as for biting insects, this was a major new change. but again, it's not like mosquitoes materialized out of thin air and vampirically drained all the blood in the world. they slowly and gradually evolved to the job they do better and better, but never THAT good a job. never, never, did they kill their hosts. because this would then kill the mosquitoes
so frankly, this story is braindead on some fundamentals of evolution and parasites
Re:poor understanding of evolution and parasites (Score:4, Informative)
so are you telling me (Score:2)
of course not
therefore, you understand my point of the supidity of saying parasites wiped out the dinosaurs
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Though I suspect there are cases where a host population spans several species and so an extinction of a species due to a parasite is therefore possible.
The d
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A Parasite that develops and is virulent enough to wipe out its host species will go extinct as a result of doing so. An evolutionary dead end, certainly, but undoubtedly an evolutionary dead-end that has occurred more than once in earthly history. Nothing and no one will step in to prevent this from happening (well, at least in my theology).
In that sense, a "successful" parasite is relat
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Well no, current species of parasitic wasps aren't generally going to; however that's just because the ones that survived up until now are the ones that stumbled upon a method that leaves a host population in tact. This doesn't mean that previous parasites didn't get overzealous and bring about their own extinction by killing all their hosts.
There's nothing about evolution which inherently prevents a species from ending itself...you just don't encounte
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Re:poor understanding of evolution and parasites (Score:4, Insightful)
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Many parasites kill their hosts (as intended).
I think you're mistaken in ascribing intent to parasites. Parasites have no intent beyond reproducing. In some situations they may exploit their niche (in this case, hypothetically, dinosaurs) to a degree of overburdening it and seriously harming or destroying it. Usually the niche - if it itself is biological - will end up compensating; or, more precisely, those entities that survive have come upon a compensation accidentally. If the parasite is still able
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We don't actually know that this was the case. Insect fossils are rare, and amber-bearing trees only go back (as far as we know) to the early Cretaceous, and ones as old as that are extremely rare (the majority of "amber fossils" are less than 30 million years old). Note also that Ixodoidea (the group that includes mites and ticks) go back at least as as far as the Devonian period, so it's very possible that parasitic forms evolved almost as soon as there
I Dunno (Score:2)
Still, lots of stuff did survive, and because "dinosaur" is a rather large and diverse group of animals, the best we can say is that it was, by and large, the megafauna that took the brunt of it, which seems logical, as it would be these species that would be at the top of their prospective ecological niches, and thus the most vulnerable.
id (Score:4, Funny)
i mean swarms of insects were mentioned in the bible (old testament, moses exodus part?) somewhere, i dont remember reading about asteroids in that book
Genesis 19:24 (Score:2)
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I'm a little confused by your apparent offense at my comment (Or poorly worded joke. I can't tell which.), but I'll take the opportunity to explain regardless.
I found it laughable that "burning sulfur" would be interpreted to be asteroids, and was asking if the reference was intended as a joke. This was neither an attack on the Bible by an athiest nor a defensive comment of a believer, but a simple question.
I apologize for not making that perfectly clear.
How dull. (Score:2)
The insects are just the FALL guys (Score:2)
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Doesn't sound likely at all (Score:4, Insightful)
"After many millions of years of evolution, mammals, birds and reptiles have evolved some resistance to these diseases,' says Researcher George Poinar. 'But back in the Cretaceous, these diseases were new and invasive, and vertebrates had little or no natural or acquired immunity to them"
Um, the Cretaceous period lasted 75 million years. So while it's plausible that insects caused outbreaks of disease in localized populations I really don't see how anything of pandemic proportions can be inferred. As far as evolved resistance goes, well, the dinosaurs dominated the Earth for a LONG time. Much, much longer than mammals. Unless the diseases described all appeared about 65 million years ago, then there's just no logic here.
Besides that, dinosarus may have died out but many other species did not. This includes reptiles, which would have been affected by the pathogens according by these researchers.
The more I think about this, the more it smells like bullcrap.
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Sounds plausible, but... (Score:3, Interesting)
You might ask what happened Mayan empire? http://en.wikipedia.org/wiki/Maya_collapse [wikipedia.org] This insect thing might not be so far fetched as you think?
Which came first? (Score:3, Insightful)
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There's one perspective that heavenly hash voted against the dinosaurs early and often.
Wait a second... (Score:2, Informative)
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I mean, just because someone has died of the flu doesn't mean I cant shoot them in the face with my revolver once they're gone.
Not saying this is likely, just that its somewhat possible, and may apply to a certain degree (IE: perhaps not all species were so harshly impacted by this need, or adapted quickly enough).
Possible, But Improbable (Score:2, Informative)
necessary (Score:2, Funny)
Somebody needs a degree (Score:3, Insightful)
Flowering plants originated 70-90 mya too. (Score:4, Interesting)
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You do realise that you are talking about an event spread out over 20 million years. The average species lasts about a million years, so there must have been plenty of time for resistance to arise. And, how can a pandemic occur? There's no international travel of dinos. And as someone pointed out dinosaurs weren't the only branch / group of animals affected. How come the ocean going lizards, eg pleisiosaur and icthyosaur, also went exinct ... because they were not dinosaurs. I think a proven asteroid impact
Two sides of the religous argument (Score:2)
a dinosaur just flew by my window (Score:2)
How about (Score:2)
Similar Theory (Score:2, Funny)
When (Score:2)
No, but... (Score:2)
Funny, I always thought it was a giant asteroid... (Score:2)
The giant asteroid model has some good things going for it, in particular the presence of charcoal fragments in and just above the K/T iridium layer in samples taken from many locations around the world. That seems to support the idea (
Wrong question -- ^kill^hurt (Score:2)
Another theory that ignores the evidence... (Score:2, Interesting)
anyway. In N. America they had declined from about 35 genera
to about 12 genera by the end of this period. The #1 reason
for their decline was the dropping O2 levels in the atmosphere
caused by the intense volcanic activity that was occurring
due to the breakup of Pangea. O2 levels were about 35% at the peak
of the Cretaceous and are about 21% today. Dinosaurs got big because
they had lots of O2 to breathe. They also didn't need to be warm-blooded
New Zealand (Score:2)
New Zealand split off from Australia about 65 MYA, and since that time has been isolated except from flying creatures.
There were dinosaurs in New Zealand after the split [natlib.govt.nz], yet they also died out about the same time as their kin elsewhere---despite their isolation.
it was that bee sting (Score:2)
Argh! (Score:2)
The real answer (Score:2)
That, or after wiping out the other species of dinosaurs, they got better, and finally Ascended.
mark "no, I'm not Daniel Jackson"
No, man (Score:4, Funny)
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