Abstract
High levels of biodiversity and endemism in ancient lakes have motivated research on evolutionary processes in these systems. Drill-core records from Lake Titicaca (Bolivia, Peru), an ancient lake in the high-elevation Altiplano, record the history of climate, landscape dynamics, and diatom evolution. That record was used to examine the patterns and drivers of morphological evolution of an endemic species complex of diatoms in the lake, the Cyclostephanos andinus complex. In an attempt to delineate species within the complex based on morphology, no discernible evidence was found for species separation based on an ordination analysis of multiple characters, but multiple populations were detected based on the distribution of valve size in individual samples. Likelihood modeling of phyletic evolution showed that size evolved through punctuated change. Correlation of size trends with environmental variables indicates that C. andinus size responded to regional environmental change driven by global processes that influenced Lake Titicaca by affecting lake level and thermal stratification.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 89-100 |
| Number of pages | 12 |
| Journal | Paleobiology |
| Volume | 44 |
| Issue number | 1 |
| DOIs | |
| State | Published - Feb 2018 |
Bibliographical note
Funding Information:We thank Maddie DeVeney, Sara Heine, Jacob Morehouse, and April Thalken for assisting in documenting Cyclostephanos andinus from the Lake Titicaca drill-core material. We also thank Jeffery Stone, Yanbin Lu, Karlyn Westover, Vicky Chraibi, and Marie Weide for insight into the development of the project, and Caroline Burberry and Scott Keely for use of their computer hardware. Comments from Ed Ther-iot, Craig Allen, Diana Pilson, David Watkins, Ross Secord, Gene Hunt, and one anonymous reviewer greatly improved this paper. This research was funded by the National Science Foundation Integrative Graduate Education and Research Traineeship (IGERT) program (NSF 0903469), the Sedimentary Geology & Paleobiology program (NSF 1251678), and the Frontiers in Earth Systems Dynamics program (NSF 1338694). The Geological Society of America, the Paleontological Society, the American Microscopical Society, and a University of Nebraska Presidential Graduate Fellowship also provided support for this project. This contribution is in partial fulfillment of the requirements for a doctoral degree for T.L.S. at the University of Nebraska–Lincoln.
Publisher Copyright:
© 2018 The Paleontological Society. All rights reserved.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
Continental Scientific Drilling Facility tags
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