Wonderful Life: The Burgess Shale and the Nature of History - Stephen Jay Gould

Stephen Jay Gould’s Wonderful Life: The Burgess Shale and the Nature of History is both a brilliant history of the Burgess Shale fossils and its discoverer Charles Doolittle Walcott, and an in depth look at the zoology of the animals behind the fossils. However, this book is not an easy read in many ways and is certainly not for the faint of heart. Gould does not hold back on the zoology. He bandies about scientific terms and evolutionary debates as though every potential reader has at least a Bachelor degree in biology. Yet despite of my own background in invertebrate zoology and taxonomy, there was a period of time where I put the book down and wondered, “Why am I pushing myself to read this?”. Perserverence is key, as by the time Gould wraps up the book all of the time spent learning about the work done in the 1970s on these fossil animals makes perfect sense.

Gould proclaims the Burgess Shale the most important fossil bed in the world as it was the first major find of fossils of soft-bodied creatures from the period just after the pre-Cambrian explosion 570 million years ago. The Cambrian explosion itself is important as it “marks the advent (at least into direct evidence) of virtually all major groups of modern animals – and all within the miniscule span, geologically speaking, of a few million years”. For Gould, the story of the Burgess Shale is interesting on a human scale from where classification of the fossils began with Walcott, the discoverer, and where it ended up with the reexamination by Harry Whittington of Cambridge University.

When Walcott discovered the Burgess Shale in southeast British Columbia during a field season in 1909, he was the head of the Smithsonian Institution in Washington, DC. Walcott’s commitments to administrative tasks led to years of putting serious research into his Burgess fossil collection on the backburner. He published a few preliminary papers, and a few monographs on some of the sponges and algae but none on the more complex animals. Unfortunately Walcott was not able to spend more time with his fossils during his retirement as he died shortly after it began.

After his death, Walcott’s wife prevented any serious study of the Burgess Shale fossils, primarily as she believed no one was up to the task. The massive fossil collection languished on high and out-of-the-way shelves in the Smithsonian. No paleontology student or research was likely to come upon them and have a eureka moment that would launch them into a lifetime of research, further pushing the Burgess Shale fossils to the back of every paleontologist’s mind. It was not until 1959 that one of the first major post-Walcott publications on Burgess Shale arthropods appeared. Leif Stormer, a Norwegian paleontologist, created a classification scheme published in the collectively written “Treatise on Invertebrate Paleontology”. Stormer’s classification was entirely different from Walcott’s, bringing nearly all arthropods into the same grouping as trilobites based on what he saw as similarities in their primitive appendages.

It was with Stormer’s classification that Harry Whittington, a paleontologist out of Cambridge University, and his two grad students, Derek Briggs and Simon Conway Morris, began their own intensive study of the Burgess Shale fossils. Much of this book is a discussion of the dilemmas thrown up during fossil study. Whittington started with an analysis of Marrella splendens as it is by far the most abundant fossil in the Burgess Shale. Walcott, in 1912, admitted that Marrella was not a conventional trilobite, but still placed it in the class Trilobita even as some of his contemporaries expressed their doubts. However, even these doubters did not stray from the notion that all of the Burgess fossils should fit into classification groups already known, even if they did not seem to fit. In 1971 Whittington knew that Marrella was different, but even he felt constrained by the belief that Burgess fossils were old yet primitive versions of modern species, and to keep Marrella in the Class Trilobita despite evidence that suggested otherwise.

For example, when he was working on reconstructing Marrella’s head with its appendages, he came up with a very different configuration than Walcott. In fact, Stormer had also seen differences in his own reconstructions compared to Walcott, and had decided to ignore the head when making his classification (instead concentrating on leg structure). Upon studying the illustrations Walcott had made of Marrella’s head, Whittington noticed that they had been retouched to the extent that they were essentially falsified, showing mouth part features that were not there. Despite these differences, and those Whittington noticed in the legs, Gould writes that “on the brink of a transforming insight he chose caution and tradition this one time – and placed Marrella in Stormer’s Trilobitoidea…yet as he did so felt the pain of betraying his own better judgment.”

Regardless, this first study and its conservative conclusion by Whittington eventually led to a revolution in classification of the Burgess fossils. The third Burgess fossil Whittington worked on, Opabinia, was what Gould calls a “eureka moment” in this restudy. By dissecting one of the ten fossil specimens of this organism, Whittington found that Walcott had been mistaken in his classification: it did not have the right leg appendages to be classed as an arthropod, nor did it have any features that would classify it in any of the known groups. It was an orphan. Finally, Whittington was able to free himself from the constraints of fitting a specimen into the existing scheme, and could simply describe an organism as he saw it, writing in his monograph, “My conclusions on morphology have led to a reconstruction which differs in many important respects from all earlier ones.”

The more Burgess organisms Whittington’s team investigated, the more they confirmed that Burgess organisms in the Cambrian showed body plans beyond the range of those seen in later times. There was tremendous diversity and disparity at the time, and as evolution proceeded this was whittled down to fewer different body plans in fewer different groups of organisms. These reclassifications of Burgess fossils are significant, as they demonstrate how the beliefs and world view of society or the paleontologist of the time can affect how the fossils are seen to fit in to the evolutionary record. More generally, how the personal views of a scientist can affect their interpretation of a revolutionary scientific idea. Gould associates Walcott’s “shoehorn” of Burgess fossils into existing taxonomical groups with his traditional, conservative, political, social and religious beliefs.

The remainder of the book is an exploration of this as Gould postulates evolutionary “what if” scenarios that challenge the notion that there is only one way to think about the progression of life, based on preconceptions of scientists like Walcott. Gould ends up reminding us that we should not let ourselves be led into thinking that there is only one path to take, one choice, one way of doing things because it is the one that we are willing to accept based on our expectations or comfort level. We need to explore what is possible, and be willing to accept even the most revolutionary idea, the most revolutionary change.

Cascadia's Fault: The Coming Earthquake and Tsunami That Could Devastate North America - Jerry Thompson

First Nations peoples of the Pacific Northwest have passed down stories for generations about a winter’s night when the ground shook terribly and an enormous wave hit the coast and wiped out entire communities. The Europeans who began to populate this region in the 1800s did not pay attention to these stories, nor did few others until the mid to late 20^th century when it turned out that these First Nations stories were rooted in fact, and that this part of North America was not a special aseismic region of the Ring of Fire. “Cascadia’s Fault” is the story of the decades-long multi-disciplinary search that led to the scientific evidence and conclusion that one day in the future the Pacific Northwest will be struck by another devastating earthquake.

Journalist Jerry Thompson begins the story of the search for the Cascadia Fault by explaining where it started. For a long time earth scientists and residents believed that because the region from the north end of Vancouver Island to the Oregon-California border had been essentially tremblor-free in all of recorded history (since European contact), because there was no obvious fault line or trench, it was assumed that the two tectonic plates were moving smoothly past each other and there was no danger to the region. It was the 1985 earthquake in Mexico City that got West Coast geologists questioning whether this theory was correct as the fault off the west coast of Mexico was also deemed aseismic…and was very similar to Cascadia, except shorter.

This questioning led researchers back to 1964 when a tsunami hit the small Vancouver Island town of Port Alberni after the 9.2 megathrust quake in Prince William Sound off the Alaskan coast. There were incredible changes to the region: an area the size of the states of Washington and Oregon combined had heaved up or dropped down, the sea floor appeared to have lifted more than 15m, and the land also stretched horizontally up to 20m between the city of Anchorage and the edge or Prince William Sound. This quake was surprising because after it happened no one was able to say which fault had ruptured and why this fault had gone undetected for so long. However, because the scientists studying this earthquake were doing so just at the time that the theory of plate tectonics was becoming more popular, it took many years for scientific conclusions about the geology of the region to be accepted: that off the West Coast of North America were subduction zones (horizontal cracks in the earth’s crust).

All of this led scientists back to searching for clues along the Washington and Oregon coast that might shed light on the seismic history of the Cascadia fault. The remainder of the book concentrates on this research. Thompson describes how surveying engineers had set up geodetic markers on mountaintops and were using lasers and GPS co-ordinates to determine whether or not there was any movement in the peaks. There was – the mountains of Vancouver Island were being squeezed landward, towards the mainland, about 20cm in less than 40years. Hundreds of kilometres worth of mountain rock were being pushed horizontally yet even then selling the idea that a subduction zone was locked and building up energy for a future earthquake was difficult. More evidence was needed to show that there was plate tectonic activity here and that it had led to past earthquakes.

Thompson then introduces two Washington scientists: Brian Atwater and David Yamaguchi. Atwater, in 1986, discovered what he calls the ghost forest not long after his discovery of another region northwest of Seattle that showed layers of sea sediment and plants above layers of land sediments and plants:

This was no gentle or gradual transition zone from one geologic era to another. The peat had a sharp upper boundary caused by an almost instantaneous and probably cataclysmic change in the level of the land and sea. Was it physical proof that the ground had slumped during an earthquake, that the plants of a marsh or forest meadow had been drowned quite suddenly by the incoming tides and possibly buried under the sands of a huge tsunami?

Good question, and the ghost forest raised another that tree scientist David Yamaguchi attempted to answer: when did this forest end up swamped by salt water, killing the spruce trees? By studying the tree rings, Yamaguchi managed to narrow the timeframe for the last earthquake along the Cascadia Fault to sometime between 1680 and 1720. Despite cutting and counting rings on both dead and witness trees (those living at the time the others died), Yamaguchi could get no closer. However, in 1994 a Japanese geologist who specializes in subduction zone and tsunami research, Kenji Satake, learned of these dates and their association with an earthquake and was immediately intrigued. While North America did not have written records at that time, Japan did, and it was in those records that Satake made an amazing discovery. In historical documents found in four separate town there was mention of a 5m tall tsunami in 1700, and the only place it could have originated was from the Cascadia fault. By calculating backward, the quake was estimated to be at least magnitude 9. They were also able to calculate even more. As Satake wrote in Nature:

The earliest documented tsunami arrival time was around midnight on 27 January, Japan time. Because tsunami travel time from Cascadia to Japan is about 10 hours, the earthquake origin time is estimated at around 5:00 on 27 January GMT or 21:00 on 26 January local time in Cascadia. This time is consistent with Native American legends that an earthquake occurred on a winter night.

Finally, by 1997, it became a known fact that Cascadia is an active fault whose next rupture would have major consequences for at least five North American cities. This is why Thompson’s book is so important. This information is barely 15 years old but has already been taken seriously, but perhaps not yet seriously enough because there just seems to be no reliable way to predict when an earthquake will hit. There have been some efforts to make BC, Washington and Oregon earthquake disaster ready, but there is still a long way to go to both raise public awareness and emergency response standards to a level that would be able to deal with events on the scale of the 1995 Kobe quake and the 2004 Sumatra tsunami.

Every person in the Pacific Northwest should pick up this book and both enjoy the history and explanations written in an interesting and accessible manner for even those with the most minimal knowledge of geology, as well as the implicit and explicit warnings that it has happened before and will happen again, so we had better be prepared.

Emergency Management BC website with information about earthquake preparedness: http://embc.gov.bc.ca/em/hazard_preparedness/earthquake_preparedness.html