Published 11/10/10

cross-section of an Arctic Miocene fossil

This cross-section of an Arctic Miocene fossil was photographed by Associate Professor of Biology Qin Leng using a scanning electron microscope.

Fossilized hints of climate change

SMITHFIELD, R.I. (Nov. 10, 2010) -- By peering deep into the molecules of fossilized conifer needles, a Bryant University senior has become a partner in a Bryant faculty member's research into global climate change.

Caitlyn Witkowski '11, an environmental science major, and Hong Yang, Ph.D., professor of science and technology in Bryant's College of Arts and Sciences, recently discussed their findings in separate presentations at the annual meeting of the Geological Society of America (GSA) held Oct. 31-Nov. 3 in Denver. In doing so, Witkowski, of Saint James, N.Y., became Bryant's first undergraduate to present research at the national GSA conference attended by nearly 6,000 scientists.

By peering deep into the molecules of fossilized conifer needles, a Bryant student becomes a partner in a faculty member's research.

Witkowski performed a molecular-level assessment of 15-million-year-old fossilized conifers that once thrived in the high latitudes of the Canadian Arctic during the Miocene era — a time when the earth's climate was warming. Other scientists have conducted similar analyses on fossils found elsewhere, but Witkowski is among the first to zero in on newly discovered fossils found on Banks Island, Northwest Territories, Canada.

Her studies determined that the molecular components of these rare fossils are extremely well preserved, more so than 45-million-year-old Arctic fossil conifers analyzed by Professor Yang in 2005. Such findings paved the way for further molecular-level analyses using other organic geochemistry and stable isotope technologies. Working with Qin Leng, associate professor of biology at Bryant University, they found in these fossils the link between molecular composition and three-dimensional preservation, which is a very rare mode of preservation in plant fossil material.

"Presenting your results, arguing your point of view, and receiving criticisms from your peers at a national conference are essential steps of doing research," said Yang. "For an undergraduate to have such an experience early in her scientific career is unique."

The quality of such fossils is critically important to Yang's research in paleoclimatology and paleobotany. Using plant fossils, especially hydrogen isotope ratios from Metasequoia (dawn redwood), one of the fossilized conifers with modern representatives still living in remote valleys in southern China, Yang has had a rare opportunity to investigate ancient Arctic warming cycles and the mechanisms behind them.

For his GSA presentation, Yang shared information about precipitation in the Arctic during the middle Miocene period — a time when what is now the polar ice cap was covered by an extensive Metasequoia forest. Using molecular and isotope analyses of fossilized Metasequoia and other plants — the same fossilized material used by Witkowski — Yang drew parallels between the Arctic climate of the Miocene and those of the present day and explored the implications for the future.

Witkowski was the first author on the study presented to the GSA. Collaborating with her were Yang and Leng; Neal Gupta and Derek Briggs of Yale University; Roger Summons of Massachusetts Institute of Technology, and Christopher Williams of Franklin and Marshall College. Yang's partners in the study presented to the GSA were Leng and Williams.

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