GeologyRocksA new theory for Dinosaur extinction
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A new theory for Dinosaur extinction
Thu, 03/23/2006 - 16:20It sounds like both mammals and birds have extra connections in certain parts of the brain that reptiles do not, and that these support the fixing of memories in deep sleep and therefore learning. As both mammals and birds evolved separately from reptiles, both must have evolved these connections independently. Assuming the dinosaurs didn't also develop these in their own evolution, it is suggested they were less adaptable.
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A new theory for Dinosaur extinction
Mon, 03/27/2006 - 21:02It was in the Daily Mail as well! So MUST be true! Sounds a bit unlikely to me, but I do believe they were on the way out prior to the meteorite impact, more than likely due to the eruption of the Deccan Trapps.
And the PT event coincides with the dating of the Siberian Trapps.
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A new theory for Dinosaur extinction
Fri, 03/31/2006 - 10:04Well it seems that Chicxulub didn't kill off the dinosaurs anyway - however it may have wiped the ammonites out...
http://www.geolsoc.org.uk/template.cfm?name=ChicxRoost
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A new theory for Dinosaur extinction
Sun, 04/02/2006 - 13:12Well it seems that Chicxulub didn't kill off the dinosaurs anyway - however it may have wiped the ammonites out...
Thanks for the link Simon, that's really interesting.
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A new theory for Dinosaur extinction
Thu, 10/12/2006 - 14:11In a geology lesson at college we learned that before the crater on the Yucatan peninsula was found one theory for dinosaur extinction was that most dinosaurs turned either female due to climatic events. If I were a dinosuar I would be glad of the meteor.
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A new theory for Dinosaur extinction
Sun, 10/15/2006 - 09:38I'm not so sure about N. Korea. There is no evidence that there was anything nuclear there (and unless anything leaks 2km to the surface there won't be). It is in both N Korea's and America's interest to suggest that it was nuclear (for different reasons). The magnitude was a bit small and 500 tonnes of TNT or equivalent would have done just as well.
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A new theory for Dinosaur extinction
Tue, 10/24/2006 - 13:21I quite like Volcanogirls idea that 'they had their chance and blew it'. Though a problem with this is that it suggests that there is an overiding guiding principle to evolution rather than a series of chance events. Did the dinosaurs know at the time that they were 'having their chance'?
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A new theory for Dinosaur extinction
Mon, 10/30/2006 - 09:22It sounds like both mammals and birds have extra connections in certain parts of the brain that reptiles do not, and that these support the fixing of memories in deep sleep and therefore learning. As both mammals and birds evolved separately from reptiles, both must have evolved these connections independently. Assuming the dinosaurs didn't also develop these in their own evolution, it is suggested they were less adaptable.
Can I ask how we know that the dinosaurs did not evolve those connections? Dinosaurs aren't the same as reptiles, so how can we use what we know about reptiles to understand dinosaurs?
That would be like using knowledge of birds to understand mammals, wouldn't it? Or am I being stupid?
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Personally, I like the idea
Thu, 07/26/2007 - 13:48Personally, I like the idea that the earth was hit by a large meteor and smoke and ash covered the planets and everything exept water creaters died because of the smake. There is some proof. For example, In many areas of the earth there is a small layer of black soil filled with dinosaur fossels and mony other creatures about the time the dinosaurs went extinct. And it wasnt just one meteor. It was probably a meteor the size of the moon that spit up in the atmosphere causing many meteors to hit all over the world. The largest being in new mexico where it left such a large crater, you can still see it today.
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A new theory for Dinosaur extinction
Submitted by Jon on Wed, 03/22/2006 - 16:28.I saw this in the Metro this mornning, but it took me a while to track down the source...
A new theory is being proposed that blames the extinction of dinosaurs on a lack of deep sleep. Well that's what the headline said (and has been repeated several times). Apparently the original source of the headline is the Scotsman: http://thescotsman.scotsman.com/index.cfm?id=447482006
The original source is:
Brain Research Bulletin 69 (2006) 20–29
Abstract:
Mammals and birds are the only animals that exhibit rapid eye-movement (REM) sleep and slow-wave sleep (SWS). Whereas the electroencephalogram (EEG) during REM sleep resembles the low-amplitude, high-frequency EEG of wakefulness, the EEG during SWS displays high-amplitude, slow-waves (1–4 Hz). The absence of similar slow-waves (SWs) in sleeping reptiles suggests that the neuroanatomical and neurophysiological traits necessary for the genesis of SWs evolved independently in the mammalian and avian ancestors. Advances in our understanding of comparative neuroanatomy and the genesis of mammalian SWs suggest that the absence of SWs in reptiles is due to limited connectivity within the pallium, the dorsal portion of the telencephalon that includes the mammalian neocortex, reptilian dorsal cortex and avianWulst (hyperpallium), as well as the dorsal ventricular ridge in birds and reptiles and the mammalian claustrum and pallial amygdala. In mammals, the slow oscillation (<1 Hz) of cortical neurons acts through reciprocal corticothalamic loops and corticocortical connections to synchronize the 1–4 Hz activity of thalamocortical neurons in a manner sufficient to generate SWs detectable in the EEG. Given the role that corticocortical (or palliopallial) connections play in the genesis of SWs in mammals, the degree of palliopallial connectivity might explain why birds show SWs and reptiles do not. Indeed, whereas the mammalian neocortex and avian pallium show extensive palliopallial connectivity, the reptilian pallium exhibits limited intrapallial connections. I thus propose that the evolution of SWs is linked to the independent evolution of extensive palliopallial connectivity in mammals and birds. As suggested by experiments functionally linking SWs to performance enhancements, the palliopallial connections that give rise to SWs might also depend on SWs to maintain their efficacy.
Now having read the article (and not understanding most of it), it does not talk about dinosaur extinction at all (in fact dinosaur is mentioned twice in the article, once when describing the evolutionary history of birds, the other in a reference title!). So although this is probably interesting research, I can't see where the lack of sleep and dinosaurs dying out are related...
Jon
Geologists are gneiss!!