NPF: TRIAL AND ERROR

In 1909 a vacationing paleontologist named Charles Wolcott happened upon some very interesting looking plant and animal fossils in the Canadian Rockies, near the border of Alberta and British Columbia. The fossils were exciting (to a paleontologist) in that they preserved soft features extremely well, which is a rarity – usually features like bones and hard shells are distinct in a fossil but not much else. Over the next 30 years Wolcott returned often to locate, study, and categorize the species he found. Eventually he determined (correctly) that they dated from the Middle Cambrian. Thus they excited a handful of paleontologists with a niche interest in that time period, and the fossils from the site, which became known as the Burgess Shale, held the oh-so-thrilling distinction of being the oldest soft tissue fossils ever discovered.

Wolcott and his fossils remained in that strange limbo of academic fame-obscurity, his work well known to a small handful of people but otherwise wholly ignored. Then in the 1960s some enterprising graduate students re-examined the thousands and thousands of Burgess Shale fossils and found something curious. In keeping with scientific orthodoxy of his era, Wolcott had carefully, meticulously – obsessively, even – categorized every one of his finds into an existing family of plants or animals. The students noted that much of what he found was so utterly bizarre and unlike anything alive today that Wolcott had actually found a lot of species the likes of which have never been seen before or since.

What is particularly interesting, presuming one understands evolution, is how wacky some of the body plans nature "experimented" with during that era appear today. The Smithsonian keeps a nice gallery of what some of the Burgess Shale creatures looked like; suffice it to say that the whole four legs, two eyes, one mouth thing hadn't quite caught on yet. One – an arthropod called Opibinia – had five eyes on stalks and a long elephant-like trunk with a clawed mouth on the tip.

There is an active debate among people who understand such things better than I do just how unique the specimens of the Burgess Shale truly are. Some scientists believe that they are far less bizarre than some early interpretations have suggested, while others maintain that it indeed represents a snapshot of the "Cambrian explosion" which saw the phenomenally rapid expansion of forms of complex life on Earth. I think the understanding of what happened 600 million years ago will always involve a healthy amount of conjecture, but it stands to reason that any sudden proliferation of kinds of life forms would involve a great deal of trial and error. Especially at such an early stage in the evolution of life, there had to have been a lot of false starts before a general blueprint of animal life – adapted to breathing oxygen, resistant to the deleterious effects of solar radiation, and with the basic senses necessary to sustain life long enough for reproduction – was settled upon.

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21 Responses to “NPF: TRIAL AND ERROR”

  1. Warden Wombat Says:

    I recall reading Gould's book about the Burgess shale fossils, called, I think, "Wonderful Life" back in the 70s & thinking that all of these things looked like what scurries away when you overturn a rotting log. But it is true that the appearance of the homeobox (HOX) gene complex stabilized the body plans of practically all of the forms of life we can see with the naked eye, from arthropods to mammals. Half a billion years ago, those developmental genes had not become standardized, I believe.

  2. Talisker Says:

    Good stuff, Ed. And one of the many, many reasons why creationism is a big pile of dumbosity.

    Weird extinct sea creatures? Yeah, they must have drowned in Noah's flood. Hang on, that doesn't work, they're sea creatures. OK, I guess God just didn't like them. As the biologist JBS Haldane observed, the Creator, should he exist, has "an inordinate fondness for beetles."

    I disagree though with Ed's remark:

    a lot of false starts before a general blueprint of animal life – adapted to breathing oxygen, resistant to the deleterious effects of solar radiation, and with the basic senses necessary to sustain life long enough for reproduction – was settled upon.

    Don't sell the Cambrian critters short. Every last one of them was a hard bastard, swimming around in a sea full of other hard bastards doing their very best to kill and eat one another. They were descended from millions of generations of ancestors who were likewise hard bastards.

    Natural selection can be exceedingly arbitrary. Even "successful" species have usually gone through population bottlenecks; which is to say at one time there were very few of them, and they could have been wiped out by simple bad luck.

    No one's quite sure how long these species persisted, but it could have been tens of millions of years. Homo sapiens is only about 200,000 years old, so a little humility is in order.

    Skip forward 660 million years, and highly intelligent alien squid may be examining our pitiful remains, and solemnly explaining how it was obvious that unruly bald apes like ourselves were never going to make it in the long run.

  3. Katydid Says:

    The Smithsonian Gallery link has creatures with fantastic names. They'd make great Pokemon characters.

  4. Major Kong Says:

    You can't fool me. I know that Noah had Trilobites on the Ark.

  5. doug Says:

    @major . exactly the other stuff is put there by the Devil to mislead.

  6. Skipper Says:

    My theory is that humans are just another evolutionary experiment that isn't working out so well. In short (evolutionary) order, we will choke on our own vomit, become extinct, and earth can go on it's merry, although scarrred up, way.

  7. Dave Dell Says:

    http://imgur.com/gallery/o79ym

    Skipper – It's my favorite comment/cartoon on what you wrote. With the hubris regarding the coming instantaneous crisis (in geological time scale 300 years is instantaneous) the human race as we know it today is "outta here".

  8. John Danley Says:

    Donald Prothero refers to this time period as the "Cambrian slow fuse" to clarify the mistaken assumption of brevity regarding the rate of selection pressure.

    I think he's on to something.

  9. anotherbozo Says:

    Thanks, Ed. A rendering of Opabinia is my new wallpaper. Purdy!

  10. seniorscrub Says:

    C'mon Ed, time to get your keyboard looked at.
    It obviously has added an extra zero to the number 60
    and autocorrecting 'million' when you typed 'thousand'????
    That's a hoot…

  11. Mo Says:

    Dunno, Katydid, how many characters would choose "Priapulid Worm"…

  12. arithmoquine Says:

    You appear to have misspelled the name, "Walcott" as "Wolcott". At least, the Burgess Shale home page spells it with an 'a'.

    The creatures are fascinating in and of themselves. What they show me about creationists is how limited and unimaginative that world view is. It's not just that their view is false, or that it can be modified to make it unfalsifiable, but it requires seeing the world between a pair of blinders. They might be able in some way to account for Opabinia and Wiwaxia and the rest, but why would you want to try? As Shakespeare wrote, "There are more things in heaven and earth . . . than are dreamt of in [their] philosophy." The world is far weirder and more wonderful than we could have imagined.

  13. Katydid Says:

    That Noah's Ark story never made sense to me, even as a small child. So many idiocies in it; how could anyone take it seriously?

  14. Clinton A Buhs Says:

    There's some basic misunderstanding of evolution near the end of this otherwise interesting post. For one, there is no end game in evolution, and there are no "errors". It's not trying to make creatures "better"–that's reverse thinking. Dawkins explains this far more eloquently than I'm doing right now, but that's the gist of it.

    The Opabinia, for example, is similar to a great many insects today which have multiple eyes or eyes on stalks. That feature was apparently right for the time and place of its existence, or it wouldn't have existed. For another, it had to have taken thousands of generations, or thousands of years, to get to that particular state. That alone is a massive success. To call it a failure is to misunderstand the definition of evolutionary success.

  15. Just Clint Says:

    Neat. I let autofill populate my full name, and it's not editable. I guess that comment's on my permanent Internets now. :/

  16. Dr. Mac Says:

    Right on, Clinton.

  17. schmitt trigger Says:

    Everyone knows that dinosaurs have existed for a couple of thousand years prior to the Flood.
    Early cavemen kept dinosaurs as pets. I actually learned that from watching "The Flintstones"
    Scientific observations do not support biological evolution!

    Who should you trust and believe?
    The Smithsonian Museum,
    or the Creationism Museum?

  18. Gil More Says:

    Katydid ,

    How did the state of Kentucky agree to subsidize a theme park based on it ?

  19. Katydid Says:

    @ Gil Mor: I don't know; Kentucky is stupid?

  20. Katydid Says:

    @Clint: don't worry, your secret is safe with us!

  21. NickT Says:

    Of course Noah had trilobites on the ark! What do you think hot pockets evolved from?!