UM-Bot Posted December 14, 2020 #1 Share Posted December 14, 2020 Scientists have determined that mass extinctions have occurred throughout history with striking regularity. https://www.unexplained-mysteries.com/news/341855/mass-extinctions-follow-27-million-year-cycle 1 Link to comment Share on other sites More sharing options...
Grim Reaper 6 Posted December 14, 2020 #2 Share Posted December 14, 2020 This is very interesting subject, I have added a video that talks about the 27 million year cycle in your link. Thank very much for sharing my friend. 1 Link to comment Share on other sites More sharing options...
Jon the frog Posted December 14, 2020 #3 Share Posted December 14, 2020 (edited) Maybe it's the time needed for evolution to create a lots of dead ends. Just a subtile catastrophe or climate change would be needed to cleaver the overspecialized and the cycle restart. Edited December 14, 2020 by Jon the frog Link to comment Share on other sites More sharing options...
Seti42 Posted December 14, 2020 #4 Share Posted December 14, 2020 I wonder if this is another example of people finding a pattern where there isn't one. Something our brains love to do... Then again, there's not enough data about mass-extinctions to say they definitively follow a cycle or not. 1 Link to comment Share on other sites More sharing options...
quillius Posted December 14, 2020 #5 Share Posted December 14, 2020 35 minutes ago, Seti42 said: I wonder if this is another example of people finding a pattern where there isn't one. Something our brains love to do... Then again, there's not enough data about mass-extinctions to say they definitively follow a cycle or not. more importantly.....this part: Quote It is worth noting of course that if the 27.5 million year figure is accurate - and given that the last mass extinction event happened 66 million years ago that reads as a contradiction to me....if we are nearly 40 million years over due then that in itself says the 27m is not accurate? 1 2 Link to comment Share on other sites More sharing options...
Abramelin Posted December 14, 2020 #6 Share Posted December 14, 2020 Hmmm..... only 5 years ago that cycle was 26 million year: https://www.theatlantic.com/science/archive/2015/11/the-next-mass-extinction/413884/ 1 Link to comment Share on other sites More sharing options...
MysteryMike Posted December 14, 2020 #7 Share Posted December 14, 2020 Aren't we currently in one? It's called the 6th mass extinction and we've been kn it once the beginning of the Holocene. It is our doing. 1 Link to comment Share on other sites More sharing options...
Myles Posted December 14, 2020 #8 Share Posted December 14, 2020 3 hours ago, quillius said: that reads as a contradiction to me....if we are nearly 40 million years over due then that in itself says the 27m is not accurate? I thought the same thing. They proved their own idea was wrong. 1 Link to comment Share on other sites More sharing options...
pbarosso Posted December 14, 2020 #9 Share Posted December 14, 2020 well, ill go with: most of the asteroids that were in a position to be flung about have already done so and theres just not much out there (or far less) to cause any major damage. the solar system is settling down. 1 Link to comment Share on other sites More sharing options...
Tom1200 Posted December 15, 2020 #10 Share Posted December 15, 2020 17 hours ago, quillius said: That reads as a contradiction to me....if we are nearly 40 million years over due then that in itself says the 27m is not accurate? Agree 100%. A quick search of extinction events throws up lots of graphics like this one: I know those labelled are just the major ones, but I can't see any clear 27-million-year cycle here. Next consider what we (think we) know about these particular extinction events: end-Ordovician: continental drift ➜ Gondwanaland drifted across the South Pole ➜ ice cap grew ➜ sea levels fell ➜ habitat loss late Devonian: lasted up to 25 million years, so extremely difficult to pinpoint one cause end-Permian: Siberian Traps volcanic activity ➜ dust clouds ➜ blocked sunlight ➜ disrupt photosynthesis ➜ collapse of food chain end-Triassic: no clear consensus end-Cretaceous: great big bloody rock falling from space Wiki lists over a dozen possible causes, and it's very probable these mass extinction events were caused by multiple triggers. Too many straws, and all that. So I can't see how any one theory is going to explain this (apparent) cycle. And I don't think we're going to find the answers in an unreferenced article in slashgear.com 2 Link to comment Share on other sites More sharing options...
quillius Posted December 15, 2020 #11 Share Posted December 15, 2020 26 minutes ago, Tom1200 said: Agree 100%. A quick search of extinction events throws up lots of graphics like this one: I know those labelled are just the major ones, but I can't see any clear 27-million-year cycle here. Next consider what we (think we) know about these particular extinction events: end-Ordovician: continental drift ➜ Gondwanaland drifted across the South Pole ➜ ice cap grew ➜ sea levels fell ➜ habitat loss late Devonian: lasted up to 25 million years, so extremely difficult to pinpoint one cause end-Permian: Siberian Traps volcanic activity ➜ dust clouds ➜ blocked sunlight ➜ disrupt photosynthesis ➜ collapse of food chain end-Triassic: no clear consensus end-Cretaceous: great big bloody rock falling from space Wiki lists over a dozen possible causes, and it's very probable these mass extinction events were caused by multiple triggers. Too many straws, and all that. So I can't see how any one theory is going to explain this (apparent) cycle. And I don't think we're going to find the answers in an unreferenced article in slashgear.com agreed, then throw in the simple fact its been 66m years since last 'suspected' extinction event.....proves there is no cycle.. Do people not bother to think before they type these days? 2 Link to comment Share on other sites More sharing options...
Tom1200 Posted December 15, 2020 #12 Share Posted December 15, 2020 2 hours ago, quillius said: Do people not bother to think before they type these days? That would take effort, and leave me no time for sitting on my fat **** watching telly. Damn my failing eyesight - which emoji is that? 1 1 Link to comment Share on other sites More sharing options...
quillius Posted December 15, 2020 #13 Share Posted December 15, 2020 1 hour ago, Tom1200 said: That would take effort, and leave me no time for sitting on my fat **** watching telly. Damn my failing eyesight - which emoji is that? sorry just in case my post was lost in translation, I mean the journalist not you 2 Link to comment Share on other sites More sharing options...
kartikg Posted December 15, 2020 #14 Share Posted December 15, 2020 23 hours ago, pbarosso said: well, ill go with: most of the asteroids that were in a position to be flung about have already done so and theres just not much out there (or far less) to cause any major damage. the solar system is settling down. Yeah that actually makes sense. Most of the bombardment is over. Link to comment Share on other sites More sharing options...
Abramelin Posted December 17, 2020 #15 Share Posted December 17, 2020 (edited) On 12/14/2020 at 3:02 PM, Seti42 said: I wonder if this is another example of people finding a pattern where there isn't one. Something our brains love to do... Then again, there's not enough data about mass-extinctions to say they definitively follow a cycle or not. I think there may be a cycle of impact events of around 27 million of years, but that 'only' a few of those impact events actually resulted in an extinction event. Saying, these extinction events are points on the graph, but don't form a graph. Edit: The impact cycle, in its most simplistic form, can be displayed as a sinusoid: The crests are the impact events. And what I meant was that only a few of those crests are extinction events. So, the extinction events are part of a cycle but don't form a cycle just by themselves. Edited December 17, 2020 by Abramelin Link to comment Share on other sites More sharing options...
Carnoferox Posted December 19, 2020 #16 Share Posted December 19, 2020 There is no 27 or 26 million year cycle of mass extinctions. This is a claim that has been recycled for the past 30 or so years, and somehow still gets published. This particular study has selectively sampled mass extinctions in order to force this result. They only included extinctions that affected terrestrial tetrapods, so all mass extinctions from the Ediacaran-Devonian are excluded. They included at least one "mass extinction" (end Jurassic) that is no longer even thought to have been a significant extinction event. For some reason they also excluded the end Pleistocene extinction event. Cherrypicked data = worthless results. 2 Link to comment Share on other sites More sharing options...
Carnoferox Posted December 19, 2020 #17 Share Posted December 19, 2020 I would also like to note that, as is typical for these studies, none of the authors are paleontologists. Understanding the different faunas of each time period is crucial to quantifying mass extinctions, so if there are no paleontologists on the team it should automatically ring alarm bells. The lead author Michael Rampino has been pushing this pet hypothesis since the 90's about how mass extinctions are on a 26-27 million year cycle and how it is all somehow related to dark matter. No real data to back this hypothesis of course, but it makes for a good story to keep selling to magazines and newspapers. 2 1 Link to comment Share on other sites More sharing options...
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