Paleobiology
Research overview
My research interest is in the evolution and extinction of plants. In particular I am interested in the role that Hydrogen Sulfide (H2S) plays in these processes. Currently I am studying the effects of H2S on plant growth, survivability and the photosystems.
Current education: Graduate student - Advisor: Peter Ward
Previous education: Bachelors of Arts & Bachelors of Science (2009) University of Washington
Research overview 2265
One of the larger hurdles for conservation biologists is how to define ecological baselines. I find it incredibly exciting to apply what I have learned from sedimentologist, stratigraphers and geochemist coupled with the accretionary growth of hard parts in aquatic animals to reconstruct historic conditions. I use oxygen, carbon and nitrogen isotope ratios reconstruct environmental conditions, validate growth, determine behavior and estimate productivy. Thus far, these tools have helped bridge gaps of information about environmental conditions of habitats and the natural history of the inhabitants before the industrial era, where anthropogenic influence dominate.
Selected Publications
2012. Ruesink, J. L. and K. Rowell,Seasonal effects of clams (Panopea generosa) on eelgrass (Zostera marina) density but not recovery dynamics at an intertidal site.Aquatic Conservation: Marine and Freshwater Ecosystems. Online.
2012. Rowell, K. Sharing Wonder in Nature. Science. 336 (6085), p. 1109.
2012. Salomon, A.K. and K. Rowell. The Art of Ecology; How Field Sketches and Notes Offer Insights into Naturein Sagarin, R. and PauchardA. Observation and Ecology: Broadening the Scope of Science to Understand a Complex World, eds. Island Press.
2010. Rowell, K., D. L. Dettman, R. Dietz. Nitrogen isotopes in otoliths reconstruct ancient trophic position. Environmental Biology of Fishes.89: 415-425.
2008. Rowell, K., K. W. Flessa, D. L. Dettman, M. Román, L. R. Gerber, L. T. Findley. Diverting the Colorado River leads to a dramatic life history shift in an Endangered Marine Fish. Biological Conservation, 114 (4): 1140-1150.
2008. Cudney-Bueno, R., and K. Rowell. Establishing a baseline for management of the Rock Scallop, Spondylus calcifer (Carpenter, 1857): Growth and Reproduction in the upper Gulf of California, Mexico. Journal of Shellfish Research. 27(4): 625-632.
2008. Cudney-Bueno, R., and K. Rowell. The Black Murex Snail, Hexaplex nigritus (Mullusca Muricidea), In the Gulf of California, Mexico: Growth, longevity, and morphological variations implications for management of a rapidly declining fishery. Bulletin of Marine Sciences. 83(2):299-313.
2005. Rowell, K., K.W. Flessa, D.L. Dettman, and M. Román. The importance of Colorado River flow to nursery habitats of the Gulf corvina (Cynoscion othonopterus). Can. J. Fish. Aquat. Sci.62: 2874-2885.
Research overview 2258
I am interested in extinction and recovery across the Cretaceous-Paleogene boundary in Montana (~65 Mya), viewed from the perspective of the post-crania of mammals. Specifically, I am investigating differences in the extinction and survival of different morphotypes, which can be used as proxies for paleoecology, locomotion and habitat.
Research overview 2202
1. Cenozoic evolution of grasses and grazers
The evolution of grassland ecosystems was one of the most profound ecological changes of the past 65 million years, but many questions remain as to when it occurred and what triggered it. A traditional, yet untested assumption is that many animals (e.g., horses, dung beetles) evolved in lockstep with the spread of grass-dominated vegetation. I investigate these questions by using a novel source of paleobotanical data, plant silica (phytolith), integrated with information from, for example, sedimentology, modern ecology, plant anatomy, and vertebrate paleontology. This work entails paleontological and geologic fieldwork in areas such as the North American continental interior, the Pacific Northwest, Argentina, Turkey, Spain, and China, laboratory work, as well as systematic, statistical, and phylogenetic analysis. Many of these projects involve international collaborators including from Duke University, Geologic Survey of Turkey, Utrecht University, Netherlands, University of Helsinki, Finland, and National Museum of Natural Science, Madrid, Spain.
2. Origin, early diversification, and biogeography of the grass clade
Grasses evolved in the Late Cretaceous, in parallel with the break-up of Gondwana. It is less clear how this species-rich and ecologically important group reached its current global distribution and what the earliest interactions with herbivores were. My research on grass phytoliths preserved in coprolites from the Late Cretaceous of India with colleagues at the Birbal Sahni Institute of Palaeobotany, Lucknow and the Panjab University, Chandigarh attempts to address these questions.
3. Ecology of Late Cretaceous angiosperms
Angiosperms had reached high taxonomic diversity by the Late Cretaceous, but were still marginal in terms of relative abundance in mid-high latitude vegetation in North America. Together with Scott Wing (National Museum of Natural History, Smithsonian Institution) and colleagues, I investigate vegetation structure and the ecological role(s) that angiosperms played in the Late Cretaceous, using an exceptionally preserved fossil flora at the Big Cedar Ridge. central Wyoming.
Research overview 2201
My research examines evolution and ecology of early mammals in the context of major events in earth history through fieldwork, systematics, and quantitative functional analysis of modern and extinct species. Current research projects focus on three broad topics.
1. Mammalian change across the Cretaceous-Tertiary boundary.
Mass extinctions play a dual role in influencing evolution (Gould 1985; Raup 1994). They are destructive in culling species and their evolutionary traits from the biosphere, but also are creative by generating open ecospace and new opportunities for survivors. My ongoing work on the Cretaceous-Tertiary (K-T) boundary in Hell Creek, Montana examines the patterns and processes of mass extinctions and the biotic recoveries that follow (Wilson 2005).
2. Mammal tooth shape and diet.
Most studies quantifying tooth shape rely on two-dimensional information to represent complex, three-dimensional teeth and use homologous landmarks (e.g., geometric morphometrics), which cannot effectively compare vastly different tooth shapes. To address these limitations, I work in collaboration with Drs. Alistair Evans, Jukka Jernvall, and Mikael Fortelius to develop methods of quantifying tooth shape that incorporate 3-D shape data but eliminate the need for homologous landmarks. Geographic Information Systems (GIS) analyses of these data have identified metrics that strongly correlate with dietary preferences in phylogenetically independent groups, namely living rodents and carnivorans (Evans et al., 2007). We are now applying these methods to infer diet in extinct mammals, like multituberculates (see image; Wilson et al., 2006).
3. Biogeography of Cretaceous mammals.
Our understanding of early mammalian evolution has traditionally been biased toward fossil data from the northern continents. However, Cretaceous mammal fossils (144-65 million years old) discovered on southern continents during the last 25 years, hint at a dramatically different story of early mammalian evolution. This is not entirely unexpected; as the southern continents became geographically isolated from the northern continents during the breakup of Pangaea, their continental biotas evolved independently from those in the north. To provide a more comprehensive view of early mammalian evolution, I have ongoing field projects and collaborations in Cretaceous deposits of under-explored geographic regions, like India, Baja California, and Africa (e.g., Rana and Wilson, 2003; Wilson et al., 2007).
Research overview 2182
Vertebrate Evolution during the Permian and Triassic
Origin of Mammals
The synapsid lineage includes modern mammals and all of their extinct relatives. This lineage is remarkably ancient, dating minimally to the Middle Pennsylvanian (~300 Ma). The earliest synapsids (such as the familiar sailback, Dimetrodon) were "reptilian" in overall cast (e.g., ectothermic physiology, simple teeth, sprawling posture, etc.), but within 100 million years nearly all of the anatomical features that characterize mammals were in place. In what sequence were these mammalian features evolved? What was the rate at which these characters were acquired? Were these features evolved once or independently in multiple groups? The bulk of my research has been devoted to gathering detailed anatomical and phylogenetic data to address these questions in a quantitative framework.
Paleobiogeography of Pangea
The largest mass extinction in Earth history occurred at the end of the Permian, roughly 251 Ma. Although the cause of this catastrophe has been difficult to pin down, its effects on terrestrial ecosystems are clearly seen in the fossil record. To date, most of the data on extinction and survivorship for this critical interval come from the Karoo Basin of South Africa. However, this restricted geographic and sedimentary area constrains the degree to which broader statements can be made about global patterns of tetrapod evolution. For this reason, I have been actively involved in fieldwork that expands the geographic coverage of Permian and Triassic localities. Recent exploration in Antarctica, Tanzania, Zambia, and Niger have produced fossils that change the way paleontologists view Pangean faunas.
Evolution of grasses and grassland ecosystems
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