Field Research

Chuck Mitchell, professor

Mules and Macroevolution: Adventures in Paleontology

Trailing behind the mules, we dragged along the bolder strewn creek bed. Our next camp site was yet another sand bar. It was wonderfully soft. We seemed to be walking back in time as well as into the cloud forests of the Amazon River headwaters. This was the same route that the Nordenskiold Expedition (a wandering band of Swedish ethnographers from the Naturhistoriska Riksmuseet in Stockholm) had trod in 1905 no doubt also trailing their mules and guided by the local descendents of the Incas. What brought my colleague Edsel Brussa (Argentine National University at Santa Rosa) and I to this still remote valley was a search for the source of the graptolite collections that the Swedes carried home from what is now NW Boliva and SE Peru. Why ethnographers collected graptolites we can only guess, but our interest in these Middle Ordovician fossils is the unique record they provide of the history of ancient Gondwana. These fossils are virtually the only know record of the Middle Ordovician graptolite fauna from this vast part of the world. They offer an opportunity to test theories of Ordovician biogeography as well as models of graptolite evolution. Indeed, it is this latter issue, and an NSF grant to study the matter, that paid our way. Our goal is to determine whether the observed history of directional change in graptolite evolution was progressive (sustained improvement in organic design driven by changes in the evolutionary fitness of individual graptolite colonies) or was a product of some other process such as species selection (based on differences in species fitness). But for all its theoretical and statistical rigor, this work still depends critically on getting out in the field and collecting well-controlled samples. Field work of this sort in Boliva, Argentina, China, the US, and (in coming years) Siberia and the Czech Republic plays a central role in my work but also in modern paleobiology in general.

Jason Briner, assistant professor

"At times it is very cold, and yes, there are polar bears, but learning the Eskimo way of life and being surrounded by dramatic landscapes always makes arctic field work rewarding."

"Some of my current research allows me to make regular visits to an Inuit community at 70° North on Baffin Island, Canada. I work with a team of researchers that study glaciers and lake sediments, which record recent climate change in the Arctic. Paleoclimate information extracted from these geologic archives allows us to understand the natural variability of the Earth's climate system; we can use this information as a context for the major climate changes in the Arctic today associated with global warming."