In this study, the corallite shapes of three species of the scleractinian genus Undaria from the Yague group, Dominican Republic, were examined through a period of time stretching from 6.4 mya to 3.4 mya, a total of 3.0 ma. Corallite shape was measured using 3 dimensional landmarks and manipulated using the well established procedures of geometric morphometrics. Differences in shape and size through time were examined using a variety of tools, including canonical variates analysis, principal components analysis, least squares regression, partial least squares regression, and a variety of evolutionary model fits. Evolutionary model fits were used to test three models against the shape and size variables: general random walk, which models a directional change through time; unbiased random walk, which models random change through time; and stasis, which models stability through time. Stasis is the most common parameter through time, supported in 9 of 15 (60%) of cases, while the unbiased random walk was supported 6 of 15 times. While there was a significant change in one species associated with environmental variables, those variables were also correlated with time and no causal relationship can be reached.
| Identifer | oai:union.ndltd.org:uiowa.edu/oai:ir.uiowa.edu:etd-1771 |
| Date | 01 May 2010 |
| Creators | Rhodes, Kristopher J S |
| Contributors | Budd, Ann F. |
| Publisher | University of Iowa |
| Source Sets | University of Iowa |
| Language | English |
| Detected Language | English |
| Type | thesis |
| Format | application/pdf |
| Source | Theses and Dissertations |
| Rights | Copyright 2010 Kristopher J S Rhodes |
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