Noise: dinosaurs, syphilis, and all that

Back in the 90s, I spend a fair amount of time reading books about the Cretaceous extinction, including several by paleontologists arguing that the Alvarez impact hypothesis was a snare and a delusion, people like Charles Officer, Gerta Keller, and Dewey McLean. More recently, Donald Prothero, in After the Dinosaurs: The Age of Mammals.

Generally speaking, I thought the paleontologists were a waste of space: innumerate, ignorant about evolution, and simply not very smart.

None of them seemed to understand that a sharp, short unpleasant event is better at causing a mass extinction, since it doesn’t give flora and fauna time to adapt.

Most seemed to think that gradual change caused by slow geological and erosion forces was ‘natural’, while extraterrestrial impact was not. But if you look at the Moon, or Mars, or the Kirkwood gaps in the asteroids, or think about the KAM theorem, it is apparent that Newtonian dynamics implies that orbits will be perturbed, and that sometimes there will be catastrophic cosmic collisions. Newtonian dynamics is as ‘natural’ as it gets: paleontologists not studying it in school and not having much math hardly makes it ‘unnatural’.

One of the more interesting general errors was not understanding how to to deal with noise – incorrect observations. There’s a lot of noise in the paleontological record. Dinosaur bones can be eroded and redeposited well after their life times – well after the extinction of all dinosaurs. The fossil record is patchy: if a species is rare, it can easily look as if it went extinct well before it actually did. This means that the data we have is never going to agree with a perfectly correct hypothesis – because some of the data is always wrong. Particularly true if the hypothesis is specific and falsifiable. If your hypothesis is vague and imprecise – not even wrong – it isn’t nearly as susceptible to noise. As far as I can tell, a lot of paleontologists [ along with everyone in the social sciences] think of of unfalsifiability as a strength.

There were lots of examples. In his book, Donald Prothero argued that the rudistid clams – the main reef builders in the Cretaceous – had gradually declined and finally disappeared a half million years before the K-T extinction: but that was noise. When people looked harder, they found that those rudistid clams were around until the Earth got walloped. He did this a bunch: every error or missing piece of data was evidence against the Alvarez hypothesis.

People do the same thing with conspiracy theories. X is impossible, so the standard account must be an elaborate lie, or at least wrong. You construct a chronology of the crime and prove that you [Edgar Smith] couldn’t have (quite) gotten from here to there and strangled the girl in the time available. Of course the time accounts contains errors – real life accounts usually do – and the author of Brief Against Death was, shall we say, motivated. Not motivated enough to avoid another kidnapping and attempted murder upon his release, though.

When people argued that the Black Death couldn’t really have been caused by Yersinia pestis – their models suggested that it spread too rapidly in rural areas to have that cause – well, they were relying on models built of sand. We’ve dug up bodies from mass graves in London and sequenced the pathogen DNA – Y. pestis, all right. When people claimed to have seen the marks of prebirth exposure to syphilis in skeletons carbon-dated to a bit before Columbus [ruling out a New World origin], they didn’t realize that those skeletons came from a fishing community, and that fish often incorporate carbon from upwelling deep water, carbon that’s been hanging out downstairs for 20,000 years: pretty low in C-14. But the idea was silly from the beginning: syphilis spreads like wildfire: coming from America could explain why it never spread over the Old World before 1494.

There are cases in which a single ‘fact’ can sink a theory, for example when you violate a conservation law, but you have to think hard and, usually, check it several times. it needs to be a situation that we understand well enough to say what’s impossible, or close to – fairly common in physics, not so common in most other situations.

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72 Responses to Noise: dinosaurs, syphilis, and all that

  1. pyrrhus says:

    When the Alvarez’s found a worldwide layer of iridium at the K-T boundary, it seemed completely obvious to everyone I knew that a meteor impact had finished off the Cretaceous. We were wrong….Turf is defended to the last man in academic disciplines, no matter how stupid the defense is from a substantive standpoint.

  2. pithom says:

    First and second pandemic plague did spread much faster on land and was much more deadly and concentrated in urban areas than third pandemic plague ever was. Since the pathogen was the same, the insect vector must have been quite different.

  3. Sandgroper says:

    I saw that there is evidence the Yamnaya had Y. pestis. Which makes sense, because in Eurasia the natural reservoir animal for Y. pestis is the marmot, which thrives in steppe terrain. So it looks likely their descendants carried it with them when they invaded westwards across Europe, where the EEF presumably had no natural resistance. That would mean the first great plague in Europe could have happened around 4,800 years ago, and would have made large scale population turnover (which we know happened) a slam dunk.

    I was reading up on Y. pestis, and saw that it is claimed that the mortality rate for the pneumonic form (person to person transmission by coughing or sneezing) is 100%. Do you believe that? I have never seen any other epidemic disease with a claimed mortality rate anything like 100%.

    • Sandgroper says:

      Of course, that would mean 100% of people who were infected with the pneumonic form died. Not everyone would become infected.

    • gcochran9 says:

      I’ve never heard of anyone surviving pneumonic plague. Untreated rabies is always fatal too.

      I doubt if the plague had much to do with the Indo-European expansion, although it’s conceivable. I predict that any EEF bodies found from the transition will have their heads bashed in, not a typical symptom of the plague.

      Descendants of the Indo-Europeans don’t show any particular resistance to the plague today.

      Homicide. What can’t it do?

      • Sandgroper says:

        Yeah – not just heads bashed in, but shins smashed, etc.

        Well, it’s a theory. I don’t come up with many – probably for good reason. I was just struck when I read about the evidence for plague among the Yamnaya, plus another quote I saw that Y. pestis has been infecting humans for 5,000 years. (I presume that means at least 5,000 years, as in evidence of plague infection has been found in human remains that old. I assume both were referring to the same thing.)

      • AppSocRes says:

        OTOH, if an invading group of warriors brings along a few diseases to which the indigenous peoples have no evolved immunity, that makes subjugating and eliminating the natives a lot easier. The European conquest of the Americas was certainly facilitated by measles, smallpox, et al.

      • Ursiform says:

        People have survived rabies, but it is very, very rare.

      • epoch2013 says:

        There is archaeological evidence for that among Funnel Beaker Culture (TBR) east of the Elbe but none west of the Elbe IIRC. However, once common G2a is a minority nowadays. Mind you, the two scenario’s aren’t mutually exclusive. Again citing from memory: The number of TBR find in Germany is far higher than the number of Corded Ware finds after their arrival. American Indians were conquered and suffered great loss from disease.

        • gcochran9 says:

          The Amerindians were tighly isolated from the Old World disease pools for something like 15,000 years.

          Was Europe isolated from steppe populations, in particular the Indo-Europeans? Nope. They’re next door. There was trade, lots of it. Would migrations have carried new diseases from the steppe to Old Europe? Is that a marmot in your pocket, or are you happy to see me?

    • RCB says:

      I think rabies kills at around 100%. But not before turning you to a zombie.

  4. JoachimStrobel says:

    I would define a real paleontologist as somebody who does not waste time with dinosaurs. They are statistically to insignificant which gives rise to all the problems that you mentioned. Extinctions can be studies, but that is better done on Ammonidea or trilobites.
    There is a group of geologists who believe, that the sediments that we see are event driven. Only sediments from a sudden event get preserved. Walk around a coast and observe the signs of the last flood events that happened in the past 10 years, but that 100 year of ebb and tide leaves nothing. And so it is with meteorites. We have to adapt to the idea, that what we see as a sudden events is a continuous one over geological times. But then, delegating impacts to the noise realm still opens the possibility for real catastrophic events causing extinctions. Excepting impacts as part of an earth forming mechanism also opens new possibilities for the path evolution took – not only through extinction but also by possibly shaping migration pathways.

  5. I think there’s a general residence to lurid-sounding theories in a lot of fields, even when the evidence is good to overwhelming, and they fit with science and common sense. An asteroid wiped out the dinosaurs! Paleo-Indians wiped out the mammoths! Horse clans off the steppes smashed Old Europe! Sea Peoples toppled Bronze Age civilization! Genghis Khan, g’g’father of a million warriors! That kind of theory belongs in the National Enquirer (or their sister journal, National Enquirer Genetics). Real scientists know all that all these events are due to ecological change, or non-linear dynamics in complex systems, or something.

    • Ursiform says:

      Everything you mention actually fits the description of “ecological change”. And all but the first are human-induced. And at least the first is pretty non-linear …

    • RCB says:

      I recently made the mistake of trying to get a handful of anthropologists (and we’re talking evolutionary anthropologists) to admit that the IQ gap between blacks and whites could be due to the rather simple mechanism of genetics. Not much luck there: they were sure it was due to some combination of intricate environmental effects, stereotype threats, gene-by-environment interactions and correlations, in utero / maternal effects, epigenetics, and probably more yet-unimagined causes.

      Of course, this was on Facebook, potentially in full view of colleagues, so I also had to deal with a lot of “virtue signaling”, as Razib Khan called it: taking the opportunity to call me a morally repugnant white supremacist.

    • RCB says:

      Also, you’re right that the obsession with complex systems is very real. The Santa Fe Institute apparently exists solely to study complexity. To me it sounds like a somewhat silly mission statement – the search for truth ought to be sufficient – but maybe it has been a productive place. Greg would probably know.

      • gcochran9 says:

        I haven’t seen anything wonderful come out of there, but I haven’t paid very close attention. People I knew at Los Alamos thought they were flakes.

        • David Krakauer was on Sam Harris’s podcast a couple months ago talking about intelligence and complexity.

          Came away disappointed because he seemed completely ignorant of the immutability of IQ (with exception of head trauma and the like). He talked about how working memory and digit span can trained (true), but didn’t mention the difference between near and far transfer and how all evidence suggests any Iq gains from training are specific and don’t transfer and they fade with time. Implied that Iq tests and the notion of g were outdated.

      • The fourth doorman of the apocalypse says:
    • Not to rag on complex systems stuff too much. Steven Pinker has a good discussion in The Better Angels of Our Nature about how war deaths follow a power law. The exponent is greater than 1, so more people are expected to die in a few big wars than in lots of small ones. Maybe there’s something going on here involving self-organizing systems at a critical threshold, as with (maybe) avalanches and forest fires.

      On the other hand, sometimes big rock fall from sky, kill everyone.

      • RCB says:

        Or… it’s a high-entropy distribution, which many possible processes can produce?
        “any aggregation that preserves information only about the geometric mean attracts to the power law pattern”

        In other words, observing a power law (or Gaussian, or any other common distribution) doesn’t tell you a whole lot about process, I believe.

    • TWS says:

      Between the time when the oceans drank Atlantis, and the rise of the sons of Aryas, there was an age undreamed of. And unto this, Conan, destined to wear the jeweled crown of Aquilonia upon a troubled brow. It is I, his chronicler, who alone can tell thee of his saga. Let me tell you of the days of high adventure!

  6. RCB says:

    So, how do you tell when it’s noise? Just be very smart?

    • gcochran9 says:

      Depends, as Bob Dole said. Any reasonable person knows that that paleontological record is noisy, so that wouldn’t have been too hard to do right. You’d have to know a lot about carbon dating to know about low C-14 in some marine carbon sources – you might even have had to read a book about it. Even without knowing about that, we know that syphilis spreads widely and rapidly given the chance. It hadn’t spread widely and rapidly before Columbus, so it must not have been given a chance…

      Smarter people would benefit paleontology.

      • Sandgroper says:

        There are problems.
        First, a lot of ‘real’ paleontology is done on pollen spores, etc. which are really unexciting to the public, so the work lacks the ‘glamour’ element that hunting for new dinosaurs has in the public imagination. It’s basically pretty dull, painstaking work, with virtually zero public recognition of its value or importance.
        Second, I don’t know about America, but in the UK and Australia, a lot of people who are not smart enough to go into higher status and higher paid professions like civil engineering, settle for going into earth sciences as a sort of second best choice, and in some cases as a kind of ‘back door’ into engineering, via the engineering geology route, so you tend to get quite a few not very smart geologists, geomorphologists, geophysicists, etc. Earth science also tends to appeal to people who have an inclination towards science and engineering, but lack the necessary ability in Math. That is not to say that there are not some very smart earth science people, there certainly are, but they are more rare, and they tend not to be numerate. You don’t need to be very smart to get a first degree in earth science.
        Finally – at my alma mater, the students who were too dumb to be accepted into anything else opted for psychology. The students who were too dumb even for psychology ended up in anthropology. The outcome of that is self-evident.
        Smarter people would benefit all of those professions, but I doubt it will happen any time soon.

        • That’s funny, one of my recent ancestors switched from engineering (dunno what kind) to geology as an undergrad because he had trouble with calculus. Ended up as an economist.

          He’d have added as much to the sum of human knowledge if he’d died at birth. Maybe more, net. I had to unlearn most of what he taught me about fixing cars.

        • Toddy Cat says:

          Actually, almost all the geologists that I know accept the Alvarez Hypothesis – it’s mostly paleontologists who don’t, and they are a breed apart, usually as much biologists as Earth Science people. They generally know all about the anatomy of the creatures that they are digging up, but often little else. As for innumeracy, back when I was in school (late ’70’s), geologists used to at least have to take calculus. However, statistics was not required, if I remember correctly

        • Janet says:

          In the US, earth science is informally known as “rocks for jocks”… so yes, your experience holds here too.

        • JoachimStrobel says:

          There were times when one would look at engineering studies the same way as one would consider working for apartheid in the RSA – and physics was not much better looked at. Without the dedicated work of Amateurs working in Earh Science ( people doing it for the love of science) the fonder of this forum would have not have a subject to co-write his book about. And it does take a certain type of people that would crawl through rocks, record the shape of fossils, compare them on a worldwide scale and come up with a chronological ranking system when other people would still try to find out why the apple falls and how the sun turns around the earth. So have a bit of mercy with the geosciences. But I do agree with the your statements in general, but on the other hand, too much smartness in geoscience would probably make the oil price drop to 2$/barrel.

  7. whyteablog says:

    In 1999, Colin Renfrew argued that the Kurgan hypothesis was false because wheels didn’t show up until thousands of years after the expansion was said to occur.

    The Ljubljana Marshes Wheel rolled along in 2002 and was dated back to about 3150 BC. Similarly, people believed that all swans were white until they found black ones.

    I make a similar point from time to time about government corruption: they only do that shit because they think they have a realistic chance of getting away with it, and if they think they have a realistic chance of getting away with it then they’ve probably done so in the past. Which means that every scandal you ever heard of is only one of the ones you’ve heard about, and the rot probably runs considerably deeper.

  8. caethan says:

    Wow, that’s an impressive fuckup from William Buckley. Are there any public intellectuals who don’t have impressive fuckups on their record?

    • gcochran9 says:

      They haven’t all managed to get a murderer released, but then sometimes the courts don’t cooperate.

      Public intellectuals don’t have a great track record.

      • caethan says:

        I think if I were the father or brother of that second girl who almost got killed, I’d have been very tempted to wait for Buckley outside his house with a tire iron.

      • Ziel says:

        Well Norman Mailer had a severe enough case of Buckley-envy he managed to outdo him by getting a guy sprung who admitted being a murderer and who proceeded to actually succeed in killing again.

      • Jim says:

        Norman Rockwell sprung some poor innocent wronged genius from prison who managed to kill quickly kill somebody in a fit of rage over some totally insignificant matter.

        • Jim says:

          I meant Norman Mailer. I don’t know why I wrote “Norman Rockwell”.

          • Martin L. says:

            Is it not true that as a general rule, the smarter you get, the more you are drawn towards sick, twisted ideologies and people?

            A majority of the guys who worked on the Manhattan Project, some of the greatest geniuses Homo sapiens has produced during its tenure on the planet, truly adored Joseph Stalin and Stalinism. I would think this same phenomenon explains Mailer and the (so-called) conservative Buckley.

            • ursiform says:

              “A majority of the guys who worked on the Manhattan Project … truly adored Joseph Stalin and Stalinism.”

              Do you have a reference for that? Quite a few, but not anything like a majority as far as I know, believed in communism. Most of them were in denial about Stalin and Stalinism. Can you quote a reference for even one who accepted the reality about Stalin and Stalinism and adored it?

            • Ananda Hohenstaufen says:

              No. Well, maybe. I wonder what the average IQ was of the women who waited to catch a glimpse of Ted Bundy at his trial, or the girls who send James Holmes naughty photos. If you google “James Holmes Cell” you can see some of them.

              The reason dimmer bulbs don’t go in for malignant ideologies is that they lack the interest and/or the cognitive equipment to understand history, politics, literature, etc. A brainy teenager will read Das Kapital and Les Fleurs du Mal and imagine himself a tortured revolutionary, his less brainy counterpart will sell dope and break into construction site trailers at night. The eroticism of the dark side is universal, but it expresses itself in different ways based on peoples personalities and endowments.

            • Jim says:

              Mailer did later express regret about his role in the whole affair. Good judgement was certainly not his strong point.

  9. MawBTS says:

    There were lots of examples. In his book, Donald Prothero argued that the rudistid clams – the main reef builders in the Cretaceous – had gradually declined and finally disappeared a half million years before the K-T extinction: but that was noise.

    I guess things get confused by the fact that mass extinctions disproportionately kill off species that were already circling the drain.

    If Earth gets slammed by a gigaton impact event like the Vredefort bolide, pandas will almost definitely go extinct. You could imagine a far-future society going over the pieces, noting that the panda population was tapering away, and thinking that pandas were already extinct by the time the rock hit.

    • gcochran9 says:

      The rudistid clams were incredibly common… but only a few places give really good & dateable fossil records.

      Rare species always look as if they go extinct before they actually do, since the gap between the last fossil and the last individual is big ( because they’re rare) . The rarer they are, the bigger the gap. So it looks as if the number of species was gradually declining, even when they really all died at once. Signor-Lipps effect.

    • Ursiform says:

      It also kills off species that are highly adapted to particular environments and therefore comparatively rare and therefore not often seen in the fossil record.

      More adaptable creatures like roaches and sharks are harder to get rid of.

  10. Pincher Martin says:

    If your hypothesis is vague and imprecise – not even wrong – it isn’t nearly as susceptible to noise. As far as I can tell, a lot of paleontologists [along with everyone in the social sciences] think of of unfalsifiability as a strength.

    “Many a man has cherished for years as his hobby some vague shadow of an idea, too meaningless to be positively false…” — Charles Sanders Pierce

  11. I need to come back here more often. So much of what is claimed as “Science” simply isn’t. Thanks for a great article.

  12. SealPup says:

    I don’t know about catastrophism. The problem is you can’t observe or recreate the mechanisms and its just a series of just-so stories. Why did only Neornitheans survive? Because they were not substrate nesters? Then how does one explain the survival of modern reptiles? Its somewhere between pseudoscience and bad science.

    Then there is the problem of thinking in boxes leading to circular arguments: there are two cases where bird remains have been reckoned Palaeocene if thought to be modern birds or relegated to the Cretaceous if thought to be toothed birds. This is very circular logic. Of course any such desire for neat chronological boundaries at all, is excessive typological thinking.

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