New Theory Explains Periodic Mass Extinctions 383
i_like_spam writes "The theory that the dinosaurs were wiped out by an asteroid impact, the K-T extinction, is well known and supported by fossil and geological evidence. Asteroid impact theory does not apply to the other fluctuations in biodiversity, however, which follow an approximate 62 million-year cycle. As reported in Science, a new theory seems to explain periodic mass extinctions. The new theory found that oscillations in the Sun relative to the plane of the Milky Way correlate with changes in biodiversity on Earth. The researchers suggest that an increase in the exposure of Earth to extragalactic cosmic rays causes mass extinctions. The original paper describing the findings is available online."
Huh. Better get to work! (Score:5, Interesting)
It's a perfectly reasonable hypothesis, though it'll be a while before we can test it. It's always a little weird though, to think of extra-solar events as relevant on a "local" scale. I mean, in the same way that Earth is endangered by rogue meteorites and asteroids, the whole solar system is vulnerable to a rogue star or brown dwarf. Anyone ever read Jack McDevitt? He's obsessed with that sort of disaster (pun intended).
Hard to get your mind around it...The odds are so long...
Re:Huh. Better get to work! (Score:5, Funny)
We're hosed.
Re:Huh. Better get to work! (Score:5, Insightful)
I'd be surprised if we haven't shot our bolt one way or the other in the next ten thousand years, and that's a conservative estimate.
Re:Huh. Better get to work! (Score:5, Funny)
Let me guess: the rats are the warriors, the hamsters are the scientists,
and a bright orange guinea pig named Dr Zeus will be in charge.
Re:Huh. Better get to work! (Score:4, Interesting)
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"Writing of the Rat" by James Blish, first published in Galaxy magazine, July 1956. Republished in "A Dusk of Idols" by Severn House, May 1996, 0-7278-4967-0.
First we arose, then the rats, then us again. Well worth reading even today, as is so for many of his works.
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It seems obvious to me that we need to spread out. In an age where a nation (or even a well-funded doomsday cult) could conceivably make the planet humanly uninhabitable through the use of nuclear weapons, the settlement of other worlds seems paramount. And it's only going to get easier to destroy the planet; as t
Re:Huh. Better get to work! (Score:4, Funny)
B. Wait about 3 generations
C. Get invaded by descendents of original colonists looking for better place to live.
Re:Huh. Better get to work! (Score:4, Interesting)
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Re:Huh. Better get to work! (Score:5, Insightful)
Re:Huh. Better get to work! (Score:4, Funny)
Needs money more than time. (Score:4, Insightful)
In any case, commercial applications for interstellar probes seem unlikely, so you might never get that wakeup call.
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Odds are (Score:2, Informative)
Perfectly reasonable hypothesis? (Score:5, Interesting)
Re:Perfectly reasonable hypothesis? (Score:5, Funny)
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not only that but mass extinctions happened a lot earlier than that and with a far less predictable pattern. which leaves us to wonder why this cycle is this recent? why isn't there a cycle like this stretching back over a billion years?
I haven't read the original paper, and the article is thin on details, so I'm not sure exactly how many events they considered... HOWEVER, I do not think you're correct about the conditions being static across spans of billions of years.
Our sun (Sol) is a member of a cluster of stars that were birthed by a nebula of gas and dust around the same time. That cluster (like all stellar nurseries within a galactic disk) tended to break apart as time went on, due to the difference in orbital speeds around the cen
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Our sun (Sol) is a member of a cluster of stars that were birthed by a nebula of gas and dust around the same time. That cluster (like all stellar nurseries within a galactic disk) tended to break apart as time went on, due to the difference in orbital speeds around the center of the galaxy.
My god, this reads like some twisted fairy tale or the Bible.
You see, Sol was different from all the other stars in his nursery. He was more advanced than his nebulous peers, and thus started orbiting sooner than all the others. One day, he came upon a rabbit in his journeys and he said, "Oh wise rabbit, why am I all alone in the galaxy?" The rabbit replied, "I will tell you, but only if you can provide me a carrot for I have been traveling very long and am very hungry." And Sol gave the rabbit a carro
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As far as the fossil record is concerned, the only things that existed beyond 550 million years ago are basically algae, bacteria, simple worms, etc. It wasn't until after that time that biodiversity really took off. It's entirely possible that this pattern goes back thro
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Biodiversity (Score:5, Informative)
Re:Perfectly reasonable hypothesis? (Score:5, Informative)
The KT event, for example, had a much larger impact on biodiversity but happened off-cycle, and is pretty clearly the result of a specific meteor strike that we already know about.
Other events may have been volcanic or meteoric or the result of something we didn't know about.
All extinction events being triggered by only one type of external condition was never very likely.
What about table 2 in their paper? (Score:3, Informative)
1:59 My:74 My
2:115 My:121 My
3:177 My:184 My
4:250 My:273 My
5:298 My:308 My
6:372 My:400 My
7:441 My:454 My
8:497 My:501 My
My calculations:
MinAgeDiff:MaxAgeDiff
56 My:47 My
62 My:63 My
73 My:89 My
48 My:35 Mr
74 My:92 My
69 My:54 My
56 My:47 My
Personally, I'm not impressed by the 62 My period conclusion based on the data they provide. Just how approximate are we talking here?
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However there is at least one supportable theory [sciam.com] for several of the larger ones: Death by hydrogen sulfide eruptions. Briefly, global warming leads to ocean anoxia and the spread H2S-spewing bacteria; death of aerobic ocean life accelerates the bacteria growth in a positive feedback until H2S concentrations also begin to spew from the oceans and kill life on land.
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It seems like a lot of evidence to have for something with nothing to do with it.
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Because what matters is the galactic plane, not the solar ecliptic. It's going to take a while (read: about as long as it'll take the Solar System) for the probe to get a decent reading.
You'd have to pass through the heliopause first (Score:2)
Re:You'd have to pass through the heliopause first (Score:5, Informative)
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Measurement By Probe (Score:2)
Re:Huh. Better get to work! (Score:5, Funny)
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Only 7 million years from now, for all you long range planners. [...] It's a perfectly reasonable hypothesis, though it'll be a while before we can test it.
I don't think it'll be as long as you think. Within 100 years we will probably have the ability to send very small probes out of our solar system at speeds which measure substantial fractions of the speed of light. At that point, we can start sending out probes to analyze the galactic "weather" of regions that the Earth will occupy further down the line. It's still a slow process (requiring decades to centuries for results), but it's probably not as lengthy a process as you're thinking it is.
Does anyone make.... (Score:2)
Re:Does anyone make.... (Score:5, Funny)
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(I'm a realist though
It burns... (Score:5, Funny)
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Well, that would explain (Score:2)
Or not. Does this theory merely half-explain what we already know or does it make other stuff that we couldn't explain come out right, too? Sounds like the former...
This theory isn't trying to explain the K-T event (Score:2)
Re:This theory isn't trying to explain the K-T eve (Score:2)
Re:Well, that would explain (Score:5, Informative)
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This would be a period of significant problems, affecting pretty much all living things, but clearly it's not the end of the world, just a period of environmental hard times.
It doesn't explain anything. (Score:2)
How/Why did the other 90% survive?
Muons can punch through rock. They'd be hitting every living thing on Earth. Yet 90% of the species seem to survive. While 10% die off.
Why not? (Score:5, Insightful)
Lot of the things we assumed about radiation back in the day (e.g. mutants and Godzilla) have turned out to not really happen so much. DNA isn't as fragile as we assumed, and while the extra rads may kill you quicker (only live to 60 instead of 80), it's not quick enough to keep you from reproducing.
We're not talking some kind of galactic nuke here...It's just a significant upswing in radiation. Hell, the fact that we've had these historically is maybe why the ecosystem tolerates increases in radiation so well.
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Take UV light. A veyr small dose causes phenotypic adaptiation to it. A little bit more cause tumors/DNA damage. A lot more causes cellular sterilization. It's all about dosage.
Let's go with that. (Score:2)
Now, subject 100,000 species to a high dosage, over generations.
Would you expect to see no problems for 90% of the species? While 10% die off?
I wouldn't. Enough radiation to kill an entire SPECIES would, logically, have an effect on other species that share the same ecosystem.
But we don't see that in the fossil record.
That's the problem. (Score:2)
That's the problem. This theory says that the radiation killed off 10% of the species on Earth.
That IS killing things off pretty well. That's "decimating" the number of species on Earth.
And we're not talking about a specific threat to specific ecosystems. The oceans didn't evaporate nor did they freeze. The radiation covered the Earth and only killed off 10% of the species. Multiple times.
That does not make sense. Either a LOT more die or it only takes out the wea
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Re:Why not? (Score:5, Interesting)
(Sorry I can't find a better link for the Eight Americas dataset: you have to download an Excel spreadsheet to get the raw data.)
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Life also started in water, that shields out the most harmful radiations. Life on land has to wait until the ozone layer was strong enough.
if a bacterium has its DNA badly injured by a radiative event, it's less likely to survive than an animal with a million cells.
The single bacterium is less likely to survive. The population of billions of bacteria isn't. Also bacteria are independent (to a point): they don't need to be nice to each other to survive, at le
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Just a thought.
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"The basic idea is that solar activity can turn the cloudiness up and down, which has an effect on the warming or cooling o
Re:Well, that would explain (Score:5, Informative)
That's odd. The post-9/11 research into the effects of jet contrails [sciencedaily.com] suggested that they have two faint effects: mild warming and mild day/night temperature moderation. But the above quote seems to contradict that.
I am now even more suspicious of the conclusions of the contrail research, coming (as it did) in the middle of the global warming craze. Right now you can't even publish the simple observation that plants will grow usefully faster on a warmer Earth; no, you have to spin it as "OMG poison ivy will get worse!" [google.com].
I'm ready to go nuclear/solar/wind, and drive an electric car, because I've always hated the power that petronomics gives to the backwards nations... but come on guys, can we at least give both sides a fair hearing?
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Well.. (Score:2)
Egan, near the end of the book, explained that energy was being transfered into extra-dimensional energy, and not sealing behind an event horizon as it normally should.
In the book, the binary was a hundred light-years away. It caused mass extinction of the flesher human race, however the digitized humans were safe.
The book was called Diaspora.
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Err.. (Score:4, Insightful)
Nah this is not correct either. (Score:5, Funny)
Everyone knows the extinctions were perfectly explained using the Theory of Intelligent Smiting.
Re:Nah this is not correct either. (Score:5, Funny)
[NO CARRIER]
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It's not a theory. If you turn your bible to Hebrews 13:1:
"Let brotherly love continue. Do not neglect to show hospitality to strangers, for thereby some have entertained angels unawares."
by this we can interpret that at some point creatures on the earth neglected "hospitality", which can be taken to mean they were far to aggressive. By doing so, they have "entertained
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Nice one, Anonymous retard. (Score:2)
A truth is a fact, and facts are trivial. You need a Theory to link all those facts together into something useful, something testable, with predictive power.
Just a theory. Jesus. Is it troll day or something?
to quote inidana jones: (Score:5, Insightful)
Indiana Jones says, "Archaeology is the search for fact... not truth. If it's truth you're looking for, Dr. Tyree's philosophy class is right down the hall."
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I agree with that statement. Jesus is just a theory. Unproven at that. Well done, sir.
Oh, that's not what you meant, is it?
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hypothesis = what or may not be, speculation
theory = how something works
Not the same thing. Or as other put it, you use that word but I think you do not know what it means. Tired of the misuse of the word
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You talk as though being a Theory is an insult. In science, for something to be called a Theory, it is quite a honor. Just look at other theories: Newton's Theory of Universal Gravitation, Einstein's Theory of Relativity, The Heliocentric Theory ...
Lower than theory is hypothesis. Even lower than hypothesis would be a conjecture. I don't think ID
Re:Nah this is not correct either. (Score:5, Informative)
LOL! You still believe that nursery school myth?
NO intelligent person in Columbus's time thought the world was flat -- as it clearly is not to anyone sufficiently observant. Columbus's problem is that he wanted to go to Asia via a western route, and everyone intelligent knew that with a circumference of about 25,000 miles, Eratosthenes having calculated it about 240 BC (as others had since). Hence they "knew" that with the sailing technology of the day, there was no way Columbus could make the voyage.
They were right, too. Had the Americas not been in his way, his expedition would have perished before he got as far as the longitude of Hawaii.
There is some evidence that Columbus may in fact have known that there was some land mass to the west considerably before Asia (the Vikings certainly did, and it is quite possible that fishermen who went as far as the Grand Banks were also aware). Whether from that he decided that Eratosthenes was wrong and the circumference was smaller (possibly influenced by Ptolemy's maps (from Geographica) which underestimated the circumference at about 18,000 miles), or whether he was just arguing that way to get backing for an expedition (with the secret purpose of discovering and exploiting just whatever land mass was there), we have no way of knowing.
That mistake alone discredits the rest of your post as to make it not even worth reading.
Re:Nah this is not correct either. (Score:5, Informative)
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Whatever. This is always such a great troll. You think. However it just shows how poorly educated you are. Enroll in university, do a year or so of genetics, microbiology and biochemistry courses, and then get back to me about "theory". NONE of that shit would work if evolution didn't work. Yet surprise, all that shit works!
"Gravity" is also a "theory". Yet 9.86 meters per second squared is the rate yo
Figure 4 in the paper (Score:5, Interesting)
Related to something else (Score:3, Interesting)
Not only is this not a new theory (Score:3, Informative)
Or Maybe... (Score:5, Insightful)
Or maybe, the increased radiation merely causes some periods of increased mutations... extinctions follow as species are outcompeted for resources.
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Not Global Warming? (Score:2, Informative)
I think you're confusing things (Score:2)
(5am posting, sorry) (Score:5, Funny)
Can we please oh please oh please call them death rays?
-1, Totally Irrelevant (Score:3, Interesting)
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what the hell do Cantor sets (lines with a fraction recursively removed from each segment) have to do with it?
Alternative theory (Score:2)
Well... (Score:5, Funny)
Call me cynical... (Score:2)
Not really (Score:2, Interesting)
inverse square law (Score:2)
asteriods (Score:2)
I'm sure increased cosmic ray exposure would increase genetic mutation and increase biodiversity though. :)
Except that... (Score:2)
I recall reading about two separate other ones, T-P in particular comes to mind. Some just need the "gun" (a crater or volcano).
So, you sort of not only need to come up with a new theory, but come up with a new theory that better fits the time lines and the details of what we think happened better than the existing one. For T-P, there are volcanic deposits that could have been involved around that tim
Since we're on the topic... (Score:2)
I think what we can learn from any theory is that our time on this planet isn't guaranteed forever. There's a reason people want to look at colonizing other planets and moons.
Interesting theory... (Score:2)
Some hasty objections (Score:5, Informative)
* My boss (David Penny, Massey University) argues that the mammals and birds were already outcompeting the dinosaurs at the end of the cretaceous, so the asteroid was at best a coup-de-grace for them.
* The "periodic extinctions" idea has been around for decades, including the possible link to oscillations through the galactic plane.
* Mass extinctions are sudden. The increase in extragalactic cosmic rays exposure would be slow, over millions of years.
* The extragalactic cosmic ray exposure changes should be highly regular. The extinctions are irregular.
NOT About Mass Extinctions! (Score:5, Informative)
Better summary title - "Life's Diversity changes with Solar Galactic Orbit". Or something like that.
Eulogies (Score:3, Funny)
Dear AU, what has become of you? You may not be extinct, but I can never find you.
Humble Promethium. Your existence was "predicted" long after your demise.
Oh 271 Seaborgium, how did you decay? Let me count the ways. Alpha decay. Spontaneous fission.
272 Roentgenium, we hardly knew you. Half extinct at the tender age of 1.5ms. You're the one we'll truly miss.
New paper, old theory (Score:3, Informative)
Here's an article from March 2005
http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2005
It's only one of many theories. The wikipedia page that points to the article above discusses them all
http://en.wikipedia.org/wiki/Mass_extinction [wikipedia.org]
You joke, but look at table 2 (Score:3, Interesting)
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Where's the proof to this theory?????????huh???????
Actually, the term you are looking for is "supported hypothesis".
Where, the "hypothesis" is the question "what if X?" and the support is some guy goes out and digs it up, graphs it out, discovers a new branch of math to show it, etc. and then publishes some papers about it saying so.
The fact you ask that dumb question without even understanding the basics of science as (supposedly) taught in 4th grade, makes you a troll.
Now go back to Digg or something.