Smithsonian talks about Cambrian explosion
Recently we had the opportunity to visit the Smithsonian National Museum of Natural History, which extols Charles Darwin as the undisputed hero of biology. (See, âAt the Smithsonian, the Museum of the Nation, it’s all Darwin, all the time.â) But Mr. Darwin has feet of clay. The Cambrian explosion, even if he realized it, threatened his narrative of slow and gradual evolution – a weakness that was exacerbated in the 20th century by fossils from the Burgess Shale.
Beginning in 1909, Charles Doolittle Walcott shipped boxes of Cambrian fossils to the Smithsonian from the newly discovered Burgess Shale in western Canada. The full significance of these fossils was not appreciated until 50 years later, when scientists dusted off the Smithsonian’s crates and carefully examined the fossils. There were vivid impressions of complex animals, they saw, which appeared to be fully formed without ancestors. Even the details of the soft parts had been preserved. Stephen Jay Gould has also observed that these fossils challenge Darwinian gradualism.
Smithsonian curators are now well aware of how these finds, and subsequent fossils from China, made Darwin’s doubt worse than what Darwin had known. How, then, would they sell the Cambrian Explosion (CE) to the public?
The method might be called interpolation: present the “before” with confidence, present the “after” confidently, then treat the CE as a minor difficulty in between that must surely fit in somehow. Two other strategies have been noted: on the one hand, the museum organizes everything in an evolving chronology that overwhelms the viewer.
On the other hand, curators have separated Cambrian history into two exhibits on opposite sides of the museum. Was this a way to avoid emphasizing the importance of CE to visitors?
The most illustrated exhibit is at Fossil Hall, where parents of children wishing to see dinosaurs would be most likely to pass by.
As for the origin of life, it is simply assumed. “The microbes strength lived on the shore 3.5 billion years ago, “visitors read in an illustrated poster,” relatively soon after the earliest known life appeared(Emphasis added). He appeared. It’s magic talk, not science. And once the microbes appeared, the implication was that they surely must have had a lot of time to tinker with molecules and invent what was to come.
The Ediacarians are presented in an acceptable manner, with a few fossil samples and an acknowledgment that âlots of questions about how they evolved and livedâ (but never whether they’ve evolved). The legends don’t explicitly say that they were the ancestors of the Cambrian animals, but they did show it under a bold title: “The Rise of the Animalsâ(More magic talk).
Of Charnia, the sign says “they were animals” but without a mouth. It is one of the four explicit designations of Ediacarans as animals. An adjacent paragraph reads: “Typical animal behaviors … had not yet evolved. âThe legends avoid mentioning the ‘Ediacaran explosion’ and extend Ediacaran’s traits as much as possible to support a vision of evolutionary progress towards real animals.
Smother the explosion
Next is the Cambrian explosion itself. Suggestive legends say repeatedly that the first animals “evolved” this or that, such as hard parts or other characteristics that “authorized to live in many new and different words. Corn “What sparked such innovation?âYou answer this key question as if chemistry does it because new animals need things. What a thought of chemistry! âAs calcium has become more available in warmer seas, animals used it make hard parts of calcium carbonate, and, with more animals eating other animals, a tarp was a big plus. “Problem solved! Thanks, calcium.
Then “Life gets complicated,” says a poster. How? ‘Or’ What? The cells became more complicated because oxygen was more available. They just did. Just add oxygen.
Another sign also gives credit to oxygen. Under “Diversity explodes“, Readers discover that”Almost all of today’s major animal groups are born“(In bold in the original)” in this ancient explosion of evolution. Ah! It was an explosion “devolution. ”
Note the rhetorical ploys here. They got up. They erupted. They’ve evolved. Sure it was a blast, but it was a blast devolution. In addition, the Cambrian animals must have burst; Earth welcomed them with open arms, asking them “What took you so long?” “
Rising oxygen levels, mild temperatures and rising sea levels have made Earth more habitable for ocean life [bold in original]. Some animals began to live higher in the water, while others buried themselves in the seabed. Some hunted other animals, and many evolved new defenses. [Emphasis added.]
Once the explosion of “evolution” has been declared, the signs introduce readers to a world of trilobites, worms, caterpillars and borers of all kinds, as well as “strange wonders” such as Wiwaxia who “could be a relative of molluscs or segmented worms – or anything else. âThat pretty much covers the options, doesn’t it? Ah, the science.
The Twain will never meet
On the other side of the museum, another exhibit features some of the important Burgess Shale fossils, but with less fanfare. They are mounted in glass cases with captions in small print. Ediacarids such as Dickinsonia and Tribrachidiumthat “made a lasting impression” are displayed.
âSoâ¦ Wow! “
We are learning again that âlife gets complicatedâ. Next comes a large poster. “Simple beginnings”, what happened? “The explosion of youth.” Watch this place:
For over two billion years, life on Earth has changed very little. Soâ¦ Wow! [Bold and italics in the original.]
“What happened?” Now that they have your attention, they can give the scientific answer.
Among others, oxygen released by simple organisms gradually increased in the atmosphere and the ocean. This to make possible the development of complex life.
It is a rhetoric which would make the pride of a Soviet apparatchik. Did you grab the exhaust valve? If you find it hard to believe that oxygen has such powers, remember that it is only “one of many” things. Again, that pretty much covers the options, right?
Faithful to its strategy of saturating Darwin, the museum connects us, rational beings, to the humble verses of the Cambrian. ” We are coming from Them? âHearing that the basic bodily plans were established 542-488 million years ago, visitors read,
Your friends, family and your pet turtle may not look much like the creatures here. Corn we and our animal companions are the heirs to these ancient inhabitants of the ocean.
Not all Cambrian body plans were successful. Corn those who succeed set the pattern for every animal that followed – in water and on land.
Now go back to sleep
In the following showcase, âMeet some of Earth’s oldest life forms,â authentic Burgess Shale fossils include Opabinia, Wiwaxia, Hallucigenia, Pikaia (recognized as chordÃ©), Spriggina, and various trilobites.
Most viewers are unlikely to pay much attention to these important fossils if they notice them. We visited the museum in the company of a learned friend, Thomas Woodward (author of Doubts about Darwin and Darwin strikes back), who was eager to see the Walcott fossils. Even we didn’t notice them until the last few minutes of our visit, as we assumed they were all in Fossil Hall. (See the photo at the top of this article.)
In this opposite end of the museum, most of the Burgess fossils are tiny and the legends are in relatively small print. The trilobite displays on the opposite wall are densely mounted and numbered, forcing visitors to look at a legend to identify each. A separate display on Anomalocaris discusses only its characteristics and habitat, not its importance as a complex arthropod that challenges Darwinian gradualism.
A poster explains Walcott’s connection to the museum. After seeing the Burgess Shale in 1909, he “explored the site for the next decade, recovering over 65,000 specimens for the Smithsonian collection.” It appears that around 64,980 of them are locked in the basement out of public view.
Another poster shows nine phyla emerging in the Cambrian explosion. Stephen Meyer’s book Darwin’s doubt references at least double that number in the scientific literature.
An adjacent poster again asks the key question, “What caused the explosion of diversity in the Cambrian era? Hey, we told you that before. It was oxygen. It was climate change. It was difficult parts. It was predation. Why do you keep asking?
The fossil record shows What happened, but cannot tell us conclusively Why it happened. Changes in the earth weatherand ocean oxygen levels may have fueled rapid diversification. Another possible the cause may have been the interactions among increasingly complex animals. Competition and predation often stimulate innovation.
No matter its causes, the Cambrian explosion was unique. Never again so many radically different body planes evolved so quickly. [Emphasis added.]
Do you have the message? âWhatever happensâ, it has evolved. No information authorized.
But what was the source of the information required to build complete hierarchical body plans with new cell types, tissue types, organs, brains and behaviors? This is a question that no amount of oxygen can explain.
In the third and final segment of this photographic tour of the National Museum of Natural History, we will see what they are doing with human evolution.