Murmuration
South of Greenland in the middle of the day (this image and those below are from http://flightaware.com/live/)
In late morning the huge birds take flight. One after another they lumber into the air like pelicans, and like pelicans they spiral upward, forming long lines as they soar across the water. As a flock they fly westward over the ocean through the middle of the day, headed for the next large land. At night they return, following trackless courses through the blind dark, sensing one another’s presence even though they cannot hear or smell.
Evening near Newfoundland
Like chimney swifts they are drawn back to their nests amid the cities, warehouses, and factories. Like starlings they whirl in an endless murmuration as they move toward their roosts in the golden light of dawn. But they will not rest long. Soon they will take to the skies again in their ceaseless quest.
Daytime flights around London Heathrow
In winter, many among their number migrate like shorebirds. They scuttle to and fro between the mainland and warm islands, seeking subsistence among the tropical beaches and palm trees. Sometimes they travel like schooling fish along the edge of a coral reef, the groups passing one another in continuous gyre, ever-changing and yet with never a collision between opposing members.
Evening between Hawaii and California
Elsewhere they move like foraging sparrows, taking off and setting down in seemingly chaotic motion. Voracious and noisy, their clamour fills the air as they gather sustenance, transporting it to their homes among the towers of New York and Shanghai. They become busier and more numerous, flying farther and more frequently as they compete for resources.
Flights over China
Far from this cacaphony, the largest birds are in their true element somewhere out in the blue, out over the open sea. Like the albatross they can soar for hours with never a flap of their huge wings. Unlike the albatross, though, they are a rare sight around the great southern ocean where food is scarce. Instead, they follow their traditional migration paths, chasing the rich schools of tourists and traders between LAX and PAR, SAO and SEL.
A lone flight south of South America
Although these birds seem so successful today, as a paleontologist taking the long view I have to wonder about their continued survival. Their success may be their own greatest enemy. Like goats living on an oceanic island or jellyfish dying in a tropical lagoon, their numbers may actually be changing the environment in which they exist. In the not too distant future, environmental impacts may force their behaviour to change. Will they still be as abundant fifty years from now?
Comparison of carbon emissions (New York Times, January 27th, 2013)
This week, I started looking at these pages that show where all scheduled flights in the world are located. I was shocked by the sheer numbers along the main flyways, and intrigued at how much they look like flocks of birds or schools of fish. I wonder: has anyone ever applied the modelling of swarming organisms to the flight organization of aircraft?
© Graham Young, 2013
Legislative Harmony
The interior of the Legislature’s dome
This winter I am heavily involved in preparations for the Geological Association of Canada – Mineralogical Association of Canada Annual Meeting (GAC-MAC), which will take place in Winnipeg this May. One of the more agreeable tasks has been collaborating on the preparation of guidebooks for two fieldtrips: one to examine the Ordovician-Silurian boundary at various sites in south-central Manitoba, the other a relatively simple afternoon walking tour of the Manitoba Legislative Building.
In a corner of the Grand Staircase Hall, the walls are of Tyndall Stone, baseboards are Botticino marble, and the floor is grey-pink and pink-red Tennessee marble and Ordovician black marble.
The Legislative Building (or “The Leg” as it is often called*) is such a common sight to commuting Winnipeggers that most of us probably barely think of it, but it is a gem, both architecturally and geologically. Opened in 1920, the Legislative Building is commonly described as a neoclassical structure, but its detailing betrays a bit of Beaux-Arts exuberance, and the statuary is a strange melange of Canadian history and classical, Egyptian, and prairie mythology.
A floor in the Rotunda is composed of grey-pink Tennessee marble, Ordovician black marble, and green Vermont Verde Antique marble. Note how the stylolites (pressure solution features) in the Tennessee marble have been carefully aligned with the arc of the curve.
Geologically, the building’s interior combines acres of cut Manitoba Tyndall Stone with a carefully-selected suite of imported dimension stones: pink and red Tennessee marble, cream-coloured Italian Botticino marble, Ordovician Vermont black marble, Indiana Bedford limestone, Vermont Verde Antique marble, Québec Missisquoi marble, and a red marble breccia of unknown provenance.** Through the combined skills of architects and stonemasons, these stones have been blended into a remarkably coherent structure; there is harmony in the Legislature even when there is dissonance among the politicians within its chamber!
An unusual view of the Grand Staircase
I visited this place many times when we were working on our publication about its geology***, but I have never tired of it because there is always something new to see, some previously unobserved feature to discover. The images here are a few of the more “architectural” photos that will appear in our field guidebook, which should be available as a download later in the year.
The Grand Staircase Hall, viewed from beside/beneath the Grand Staircase (the foliage is part of Christmas decorations)
Hand-painted sign on the door to one of the committee rooms
On the Grand Staircase, the steps and railings are of Italian Botticino marble, while the wall behind is Manitoba Tyndall Stone
The quality of the Botticino marble permitted very fine carving work.
* ”Leg” is pronounced like a windowsill, not like a limb.
** To the stonemason, a marble is any limestone or related rock that is massive and can be readily cut and polished. Many of the “marbles” are, in geological terms, not marbles at all, but they all have fascinating geological histories.
*** If you wish to read the details of the Legislature’s geology, a pdf of the full article by Brisbin et al. can be downloaded here.
© Graham Young, 2013
Cross-Platform
In the modern world, it seems to be increasingly common for “intellectual products” to pass from one medium to another. It has long been the case that books have been turned into films or plays, but nowadays we have films that are made into games, Disney rides that are made into movies (I don’t think the Pirates of the Caribbean series can really be called “films”, do you?), and books that are made into websites.
But what about blog posts? What can they be turned into? Last week, I carried out an interesting experiment on the conversion of a blog post, or more properly a few blog posts, into the live lecture medium. Translation to a different platform, indeed.
A while back, my friends at the Mineral Society of Manitoba asked me if I would give a lecture at one of their monthly meetings. In the past I have often made presentations about my research, on topics such as collecting the giant trilobite, or the fossil record of jellyfish. This time I thought I would do something different, so I said, “why don’t I just tell you about the history of one or two of the exhibits we have at the Museum?”
Tech. Savvy?
I have spent much of the past week assembling a geological map on the computer. While I was doing this technical task, I had plenty of time to think about other things … like the changing nature of this sort of technical task.
Younger people occasionally ask me how they might go about achieving a career in paleontology or a related science. Much of what I tell them probably falls into the “blindingly obvious” category: get a good undergraduate degree in Earth Science or a relevant area of Biology … learn to write … a course in field methods would be very useful … learn how to gather data, and how to tabulate, graph, and statistically analyze those data … do a graduate degree … get some training in appropriate modern research tools, such as scanning electron microscopes, microprobes, and digital image analysis.
There are, however, other essential skills that may not be so obvious, but that are critical to the success of most paleontologists working at most institutions in the modern world. These are the skills involved in basic technical work. In most institutions, it will be essential that you know one or more of rock cutting and polishing, thin section manufacture, specimen preparation, technical photography, and computer graphics.
Blanketed
Lord Dufferin, snuggled beneath his blanket
Outside the Manitoba Legislative Building, a gentle snow was falling. On the west porch, feather-light Hollywood snow gathered on the statues of Lord Dufferin and General James Wolfe, blanketing them deeply in its fluffy whiteness. In the absence of wind, Dufferin grew a stunning mohawk, a coiffure midway between those of Mr. T and a tamarin monkey. Meanwhile, Wolfe acquired an ermine stole and a layer of striking white lipstick, furnishing him with the mien of a mature Boy George.
General Wolfe’s white lipstick
This scene was completely mundane and yet wonderfully strange. And it helped to show why these statues have weathered the way they have.
The Dawn of Experimental Taphonomy
Charles Walcott’s Jellyfish Experiments
At the end of November, I had the pleasure of spending several days in Denver, working with my colleague Whitey Hagadorn toward an improved understanding of the jellyfish fossil record. During that time I ended up re-reading most of Charles Walcott’s 1898 monograph Fossil Medusae, and rediscovered my admiration for this scientific pioneer.
Those who work in other fields sometimes denigrate paleontology because it is largely a descriptive science, lacking the experimental underpinnings of other disciplines. This criticism no longer holds the sort of strength it once did; paleontology has become much more of a quantitative, analytical subject in the past few decades as it has incorporated approaches from geochemistry and statistics.
A century ago, it was almost unheard of for paleontologists to carry out experiments, but there was the occasional exception as individuals attempted to find out just how their fossils might have been preserved. The discipline of experimental taphonomy (the study of decay and fossilization) actually goes back a long way, and one of its earliest practitioners was the great Charles Doolittle Walcott of the United States Geological Survey. I am tempted to say that Walcott was the earliest to do this sort of work, but undoubtedly there are other examples I am not aware of.
Haeckel’s diagram of the Solnhofen fossil Semaeostomites (re-published in Walcott, 1898, fig. 17)
A couple of decades before his 1909 discovery of the Burgess Shale, Walcott became interested in the idea of jellyfish fossilization. In part, this was because he was trying to understand some fossils he had received, collected from the Cambrian of Alabama. This interest also came from his reading of the work of Ernst Haeckel, who had published a series of papers on the remarkable fossil jellyfish from the Jurassic Solnhofen limestone of Bavaria (Haeckel 1866, 1869, 1874).
The modern jellyfish Aurelia. Walcott wondered how a fossil like Semaeostomites could have come from medusae such as these.
Walcott wondered how a jellyfish could fossilize; how could the fossils described by Haeckel have come to be? He spent a considerable amount of time contemplating the living conditions of modern jellyfish such as Aurelia and Cassiopea, reading descriptions, and observing them directly. Fortunately, he periodically visited coasts where jellyfish occur:
“While experimenting, in 1895, with some living specimens of Aurelia flavidula in the Indian River, on the coast of Florida, a large specimen was thrown into the quiet, shallow water at my feet, where it remained for some little time, when I observed that it was lying on its back and that the arms had dried and shrunken in the bright sunlight, and the body had swollen so that the genital openings and the mouth were completely lost. On picking up the medusa, I found it to be firm and hard, and when tossed on the wharf it did not break or tear. The shrunken arms were tough, and it required considerable force to pull them apart. This condition might possibly explain how a medusa, when killed by being overwhelmed by a sudden incursion of muddy sediment into the water in which it was living, might retain its shape a sufficient length of time to have the sediment settle closely about it and its cavities and to solidify, so as to make a mold of its exterior form.” (Walcott, 1898, p. 5)
Dead Aurelia on the shore of the Baltic Sea, Estonia
Following up on this observation, and thinking that any jellyfish that was fossilized must have been buried in quick-setting mud, Walcott decided to experiment with fresh medusae and plaster:
“I found no difficulty in securing plaster casts of Aurelia. A bed of soft plaster was prepared and a living medusa taken directly from the water and laid thereon and at once covered by pouring a thin mixture of plaster over it so as to completely bury it in the mass. When the plaster had set, the water in both plaster and medusa wa removed by evaporation and an opening made into the cast. It was then found that the plaster had penetrated the genital openings and cavities and the mouth and gastric cavity (so far as the latter was open), and that the cast showed the details of the form of the animal in a very beautiful manner.” (Walcott, 1898, p. 5)
One of Walcott’s beautiful photographs of an Aurelia cast in plaster (Walcott, 1898, pl. 31)
Walcott incorporated this work, including his stunning photographs, into his 1898 monograph on fossil medusae. Not only did he produce “fossils” of Aurelia for the purpose of comparison with ancient medusoids, but he experimented with producing traces by dragging Aurelia‘s oral arms across wet plaster. These, he similarly compared with various strand-like fossils that he thought might have been produced by the movement of ancient jellyfish.
In the course of developing his monograph, Walcott made significant strides toward the understanding of how jellyfish might have been preserved as fossils. Unfortunately, that did not prevent him from including in his work some phenomena that are clearly not fossilized medusae – a modern assessment indicates that quite a few of these are burrows (trace fossils) or sedimentary structures. And these non-jellyfish include the Cambrian forms from Alabama that had started him onto this line of inquiry.
Drag marks produced by moving the oral arms of Aurelia across the surface of wet plaster (Walcott, 1898, pl.33)
Of course, like other scientists of the time, Walcott had a poor understanding of sedimentation in marine environments, and of decomposition of organisms. But by carrying out those simple taphonomic experiments, by contemplating jellyfish fossils as the partial remnants of three-dimensional bodies, and by actively considering where and how medusae could have been preserved, he showed a very modern approach to inquiry. It would be impossible to complete the understanding of something so complicated within a single work, but Walcott’s study was a strong first step.
References
Haeckel, E., 1866. Über zwei neue fossile medusen aus der familie der Rhizostomiden. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie 1866, 257-282.
Haeckel, E., 1869. Ueber die fossilen medusen der Jura-Zeit. Zeitschrift für Wissenschaftliche Zoologie 19, 538-562.
Haeckel, E., 1874. Ueber eine sechszählige fossile Semaeostomee. Jennaische Zeitschrift für Naturwissenschaft 8, 308-330.
Walcott, C.D., 1898. Fossil Medusae. Monographs of the United States Geological Survey, Washington 30, 201 pp.
© Graham Young, 2012
Clearing the Decks
Car and passenger ferry, Kuivastu, Estonia
This week has seen one of those very odd conjunctions of events. Yesterday, I completed the journal edits on a review paper that has been in the works for at least a year. This morning, we resubmitted a manuscript on Ordovician pycnogonids (“sea spiders”) that has been going through the mill for even longer. Since I also just finished preparing a couple of PowerPoint presentations and am done with travel commitments for the moment, this means that there is suddenly a bit of time to think. Not spare time by any means (there is still much to be done before the year is out), but at least a lull in the action.
