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Science

Earth Recovered Quickly From Extinction Event 48

jmoloug1 writes "Traditional theory is that the earth took up to 10 million years to recover from the dinosaur extinction event. However a newly discovered site has revealed that this estimate may be way off. CNN has the article describing how quickly a tropical rain forest grew after the catastrophic event 65 million years a go."
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Earth Recovered Quickly From Extinction Event

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  • by pruneau ( 208454 ) <pruneau@g m a i l .com> on Friday June 28, 2002 @08:11AM (#3785753) Journal

    Good news guys, if we manage to trigger a nuclear winter, it will only take 1.4 millions years to have forests back instead of 10 !

    ...Plan accordingly for the food into your nuclear shelter guys.


    • > Good news guys, if we manage to trigger a nuclear winter, it will only take 1.4 millions years to have forests back instead of 10 !

      > ...Plan accordingly for the food into your nuclear shelter guys.

      Cool! With the saved space and reduced food requirements I can now plan on taking four girls instead of three!

  • by billcopc ( 196330 )
    In other news, a crack team of researchers led by world-famous physicist Mister Wizard, have been found guilty of pulling numbers out of their ass.
    • by Perdo ( 151843 )
      wrong story.. I think you want the worldcom/anderson story. This is about a quick envirimental recovery not a quik economic recovery. That will probably take longer than 1.5 million years
    • Damn shame you got modded down. Your comment is the only one close to the truth. Seems like they've all been revising their dates lately, doesn't it? Why should we believe that have any idea about them now? They insisted they were right before.
  • Krakatau (Score:5, Interesting)

    by Perdo ( 151843 ) on Friday June 28, 2002 @08:27AM (#3785826) Homepage Journal
    Krakatau volcano blew it's top in 1883. It has a ring of rainforest girdleing it's base despite it's continuing eruptions. Krakatau's explosion is still considered to be the most energetic single event in civilized history. Krakatau is now home to many species of birds, monkeys and smaller cousins of the komodo dragons.

    I'd venture that life did not take 1.5 million years to recover from the extinction event. We just have not looked in the right places for the right fossils. I'll bet that someday we will find a meteoric Vesuvius/Pele, and right on top of it we will find the fossils of life that came back immediately after the event.
    • Re:Krakatau (Score:4, Insightful)

      by Austenite ( 21871 ) on Friday June 28, 2002 @08:44AM (#3785903) Homepage
      Yes, but Krakatoa didn't cause extinctions of species, except in the (relatively) local area. The re-population by migration is nearly instant, on a geological timesecale. I mean, you're only talking 120 years. Perhaps if we'd found that a new ecosystem consisting of previously un-evolved lifeforms had developed around Krakatoa in the last 120 years, then your point about finding the right fossils might be valid.
      • Re:Krakatau (Score:1, Troll)

        by TwP ( 149780 )
        Undoubtedly, the turbo-encabulator has now reached a very high level of technical development. It has been successfully used for operating nofer trunnions. In addition, whenever a barescent skor motion is required, it may be employed in conjunction with a drawn reciprocating dingle arm to reduce sinusoidal depleneration.
      • Here's a link to the crater left by the K-T impact: http://miac.uqac.ca/MIAC/chicxulub.htm
    • by 4of12 ( 97621 )

      Yeah, but Krakatau was still limited in magnitude, despite being the largest recorded eruption in civilized history ( I think Toba [www.hi.is] in Sumatra was the largest if you include less civilized history.)

      I think the rapidity with which life regenerates has a lot to do with the magnitude of the event.

      The supervolcanoes, despite their devastating effects, don't seem to be quite as potentially catastrophic as collisions with space debris.

      A sufficiently large comet or asteroid really could wipe out so much of higher life forms that Earth might have to re-start with single cell organisms.

    • Re:Krakatau (Score:3, Informative)

      by cp99 ( 559733 )
      I agree with all of your post, bar one small point. I believe that the biggest eruption in civilised history occured at Taupo in New Zealand in 186 AD. While NZ wasn't inhabited at the time, it was recorded in China and Rome.

      If you look at a map of the North Island of New Zealand, you'll see a large lake (with great fishing). That's the caldera left behind.

      (Interesting link. [learnz.org.nz])
      • While NZ wasn't inhabited at the time, it was recorded in China and Rome.

        Actually I think you'll find that New Zealand was inhabited at the time.

        • Not by humans it wasn't.

          As I understand it, Kupe discovered NZ in approx. 950 AD, with large scale settlement occuring by 1300 AD.
    • Re:Krakatau (Score:4, Insightful)

      by MadAhab ( 40080 ) <slasher@nospam.ahab.com> on Friday June 28, 2002 @12:47PM (#3787268) Homepage Journal
      I think you're right. There's no reason to think that life would have been so devastated. Species, yes, but remember that everything that dies leaves an expansion niche for something that survives. It's possible, of course, that you wouldn't have much diversity for a while, but as surviving species expanded into different kinds of enviroments (previously made unavailable due to competing species), you'd see differentiation rather rapidly.
    • Re:Krakatau (Score:3, Insightful)

      by j_w_d ( 114171 )
      It's interesting to consider the issues about this. I had never considered that vegetation populations would be slow to recover from the K-T event. You would think that after the primary dust load had settled, vegetation would start to rebound. That would imply no more than decades for the earliest paleocene plant communities to begin to re-form. The most successfull early colonists would be forms that were not dependent upon external polinators. There would be a period following where plant populations partially dependent upon animal and insect vectors to spread and reproduce waited until the necessary vectors appeared, or the plant species adapted or became fully extinct.
      • Re:Krakatau (Score:3, Interesting)

        by Perdo ( 151843 )
        There would be a period where extremophiles ruled the earth. Given their vast variety, it would not take long for them to capitalize on areas that were both less extreme and lacking in competition. Look at some of the non-extremophile phyla life forms that nonetheless live in extreme environments. Ice worms live in glaciers and have antifreeze for blood. Blind cave dwelling newts and fish whose ancestors have not seen light for 20,000 years. Rodents who spend their entire lives underground and have an ant like organization and social structure. Arctic wildflowers that have 5 weeks of summer and are absolutely frozen the rest of the year. The ability of life to re-colonize devastated areas even if evolution is required to survive in it's new environment is well documented. Obvious examples are Krakatau but parallels can be found almost everywhere. Antibiotics are the comet to human diseases. Disease adapts to the new hostile environment and moves back in as few as 100 bacterial generations. 100 generations for arctic wildflowers to survive at the equator.

        Luther Burbank created the Shasta daisy, yellow center with white petals, around the turn of the century. I have seen them growing in Alaskan tundra. 100 years to go from Sunny California to becoming a dominant arctic wildflower.

        Recovery from the extinction event did not take 1.5 million years
  • Mount Washington (Score:1, Interesting)

    by Anonymous Coward
    On a ridiculously smaller scale, after Mount St. Helens erupted on March 20, 1980, the surrounding forest was devastated. However, it started regrowing a lot faster than most scientists predicted.
  • The site was discovered in 1994 by a state highway worker. It is scheduled to be demolished later this year in a road-widening project.

    Hopefully now that this finding is out they'll be able to postpone the demolition. Wouldn't it be dissapointing to have a discovery of this magnitude and not be able to check it out to the full extent because you're rushing to beat the demolition crew?
  • ... the extinct animals were still extinct, right? For them, there was no recovery.
  • was flourishing as early as 1.4 million years [after the event]

    That may be "quick" from some points of view, but if it takes 1.4 million years for our forests to regrow, we are in trouble...

  • Are there any links or more detailed analyses of the archaeoligical find? I'd like to know what methods of dating they were using to be able to throw around 1.4 million year numbers.

    Generally the dating methods used are quite unfalsifiable. We have no way to prove any of the data that they return.

    BTW, on a related note, where is the crater from the extinction event they refered to? Anyone have links for that?
    • Re:Dating Methods (Score:3, Interesting)

      by j_w_d ( 114171 )
      Speaking as an archaeologist, it was NOT an archaeological find. The pertinent fields are paleobotany and paleontology. Archaeology deals with human traces and the remains of human activities. The events discussed in the article relate to a period long before there were any homonids, let alone any humans. I realize many bookstores shelve dinosaur books right there alongside archaeological books, but that is merely a failing in modern education.

      The idea that geological dating methods are "unfalsifiable" is a view pushed by "Creation Science" - an "oxymaroon". Besides being the darling idea of Creationists and "young earthers," the idea happens to be based upon assumptions about science and geology that are either wrong or straw-man arguments. Geological dating methods are methodologoically justified estimates based upon empirical observation and generalization. They are not theories. If you do not like the dates and have some reason for challenging them, go out, collect the necessary data and offer your own estimate. Charles Lyell could do it; so can you. Geological dates are not considered absolute by anyone who produces or uses them. That is a practice only encountered in politics and religion.

      If you want to know more about the crater, point a search engine - google is good - at "K-T boundary Yucatan" and you will receive many pointers to large numbers of web pages.
      The name of the crater, BTW, is "Chicxulub."

      • One of the greatest threats to science today is encompassed the phrase "they are not theories." All to often some very insecure scientists will become overly convinced of their own opinions to the point of taking any critisizm as an attempted discrediting. They often retort with logic that sounds like a the school bully describing why he's the boss of everything... "If you do not like [it] and have some reason for challenging [me], go out, collect the necessary [friends] and [meet me by the bike rack after school]."

        Limitations should not be swept under the carpet, and have been acknowledged freely by every professor I've had. People shouldn't feel bullied by Science but invited to participate. For instance,

        Carbon-14 dating (among others) has limitations. Carbon dating of artifacts from Roman times shows some fluxuations of almost 100 years of items with known and dated origions. Given that they were for the most part less than 2000 years old, thats almost 5% difference in relatively fresh samples.

        I'm sure to an archeologist like yourself, this is old news, and not very noteworthy. It does not discredit carbon dating, but it does show its limitations. Scientists admit freely the limitations and will usually put a range of dates on an artifact, and base the judgements on factors including but not limited to carbon-dating and other methods.

        But as you also know, the amount of carbon-14 that is generated in the atmosphere, is not constant [webmuseen.de] over time and location. It is unlikely that two objects from the same year would come up with the same date.

        If that isn't bad enough, all dating practices based on radioactive decay are subject to statistical error as the specific decay of these atoms are random in nature.

        Raising the "Anti-Creationist" flag and rallying the troups turns science into a political spectical, and hurts science more than helps it.
        • I think that your being a little bit unfair on the parent poster. From my reading of it, he wasn't making a claim that radiodating is perfect, but rather he was disputing the orginal posters claim that dating was unfalsifiable. As this bit of untruth is often spread by "scientific" creationists, mentioning them is fair enough.
        • >>

          But C14 dating is not the technique used here...
          Attacking this method is irrelevent to the topic.

          It's not so much 'raising the anti-creationist flag' as 'just wanting people to go and learn the basics of how radiometric dating is done - including the error checking involved before they start ranting on about it'.

          For instance, your statement on the randomness shows that you don't understand the stastics of random events happening to very large numbers. But that's not going to stop you posting it, is it?
        • The orignial post was not talking about radio carbon dating, which could not have been applied. Radio carbon dating is limited in usefulness to the later Pleistocene. As regards secular variation and the other sources of error in radio carbon dating, well, that is why tree ring calibration was developed. It enhances accuracy considerably. Even so, youn still mistake the point regarding theory. Theory justifies methods. Dates used in geology, paleontology, and archaeology (except for speaking engagements and dinner) are based upon methods, which in turn are based upon theory. The theory can be falsified or modified, which will alter the methods and any dates dependent upon them. You don't "falsify" dates.

          For example the original half-life of radio carbon was underestimated resulting in systematically under-estimating ages and dates. Calendrical calibration from old world sites was consistently in conflict with radiocarbon dates and ultimately lead to improved physics of radiocarbon.

          Variation in radio carbon saturation in the atmosphere is a different problem. Since the amount of new radio carbon is a product solar weather, there are significant random variations from year to year and apparently across larger time spans as well. As you mentioned, during the period from about 2500 to 2000 years ago there some big variations that effect the use of radio carbon. These were found because of tree ring calibrations carried out with wood from the bristlecone pine. But, and this is somthing that seems to always pass under "creation science" radar, prior to the Reformation, ALL corrections to radio carbon dates have tended to yield OLDER dates. After the Reformation, the Seuss effect begins to come into play as fossil carbon from coal and later from oil dilute atmospheric radio carbon, artificially aging modern radio carbon dates. Then, finally, with the advent of atomic weapons testing, there is a brief period when there is an enhancement of atmospheric radio carbon, which at least partially offsets the Seuss effect.

          The bottom line is still that you don't falsify dates. You have to falsify the theory that justified the methods, which in turn yielded the dates. And no one outside of "creation science" should argue that such methodologically based dates are "absolute in the calendrical sense, which happens to be the strawman argument that cs employs when attempting to befuddle and bewilder their audiences.

          Now, to be fair, you DO encounter the terms: "calendrical," "absolute," and "relative" dates in archaeological literature. The usage derives from trying to differentiate between extremely different approaches to dating in archaeology. One approach is based upon historical, calendrical data (Biblical dates, Egyptian dates, Mayan dates etc.) With some exceptions, these are considered unarguable - there is no means by which they could be wrong, or so one might think. There are however serious discrepancies between Egyptian and Biblical dates that apparently cannot be reconciled. In China and Egypt whole segments of history have been concealed or deleted from most records. Calendrical dates are therefore known to have problems and there is no stated error margin that can give you an estimate of accuracy. You hope the historian you are depending upon is not lying. You hope that the corrections you are using to convert from calendar another are not mistaken.

          "Relative" dates are based upon known stratigraphic relationships of various materials in other archaeological sites. This allows us to "relatively" date our site because using methods such as seriation and intersite comparisons, the relative age of a site compared to others can be guessed.

          You will find archaeologists referring to geochemical dates as "absolute," but this means that the date can't change without a change in the theory upon which the date is based, or new methods that better implement the implications of the theory. And, since the archaeologist is "absolutely" dependent upon some else's arithmetic . . . However, texts, such as Martha Joukowsky's, that use the term also warn about the error margins that geochemical dates are subject to. So "absolute" is not being applied in an "absolute" sense.

          This is in direct contrast to your garden variety creationist telling you absolutely that the earth was created in 6,000 BC, on October 23, at 9:00 AM. The term "absolute" is being used in profoundly different ways and the creationist will not be offering any error margins. Before there can be any legitimate discussion between such different views, there has to be some aggreement upon language.


          • I agree whole heartedly, and I'd take exception to any creationist or otherwise that accuses an entire field of study to be entirely "falsefied".

            Your post is much more vigorous than mine, and explains the shortcomings of dating. I appreciate your time in working it up.

            But I hope that no one misses the main point. The tendancy people have of drawing lines and categoricaly throughing garbage across that line is idiotic. Specifically for a person of science (from a person of science) to fly the flag of science as a banner of perfection in defence of their claims is irreprehensible, as I believe the poster I responded to was doing.

            True science is much more humble and unpretensious, eager to discover truth through the metrics of usefulness(1). At least it should be.

            (1) Here usefull is not a judgement of a theories applicability to humanity, but an ecapsulation of the goals of the scientific method to find reproducable results. i.e. if the results are reproducible, then the theory is "useful".
            • True science is much more humble and unpretensious, eager to discover truth through the metrics of usefulness(1). At least it should be.

              I would not go THAT far. If scientists were particularly humble, we would still be in the Middle Ages. I would say that scientists in general have to be not only egotisitical enough that they believe they can identify an issue of nature or society, but that they can also explain it, AND defend their explanation on the assumption that is as good as any and better than most. In this sense the process of science is quite Darwinian and the property of "utility" is the locality upon which selection operates.

              No, there has to be plenty of ego in science. In fact, I suggest that key themes in stories like Frankenstein are founded upon the common social distrust of such egoism. But then, I like to think I do science and that I do it as well as most;-).

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