Evolutionary Processes in Neogene Planktonic Foraminifera atHigh Resolution and Paleoceanography

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The P.I.'s previous studies have provided much new data towards an understanding of evolutionary processes and have reaffirmed the belief in the high potential of studies of the late Neogene planktonic foraminiferal Globoconella group for evolutionary insights. Briefly, there are several principal factors that, in combination, provide opportunities that may be exploited through this program: 1. Large numbers of well-preserved, measurable specimens in continuously cored sedimentary sequences of late Neogene age (7 Ma to present) offer a high potential for time resolution due to core quality resulting from use of the hydraulic piston corer. 2. Clear evolutionary changes at all latitudes shown by the species shape (biometric) investigations. 3. Sufficiently broad geographic coverage of the sequences will reveal the role of migration and biotic competition in the evolutionary process. 4. The location of sequences in distinct surface water masses separated by oceanographic fronts acting as partial barriers to planktonic foraminiferal species and which acted as partial barriers to gene flow during the last several million years. 5. The existence of paleoceanographic information from the same sites for which the evolutionary investigations are being conducted. This includes oxygen and carbon isotopic stratigraphy and abundance variations in planktonic foraminiferal assemblages. 6. A suite of easily recognized morphometric features that are now accurately and rapidly measured using the well-developed methodology.