CAREER: Framework for Investigating Physical Evolutionary Constraints Using 3-dimensional Data with Application to the Plesiosaurian Neck

University Of Oregon Eugene, Eugene OR

Investigators

Abstract

Organisms physically interact with their environments, and therefore the evolution of their shape and size is expected to be constrained by physical principles. The PI will develop a framework to test this assumption quantitatively by combining recent 3-dimensional computation techniques (fast 3-dimensional digitization, Finite Element Analysis [FEA], and 3-dimensional printing) with physical experiments (flume test and mechanical properties measurement). As the first test case, the framework will be applied to a group of marine reptiles from the age of dinosaurs (Plesiosauria: Reptilia). Some plesiosaurs are known for long necks (up to 6 m long, containing about 70 vertebrae), but there is no consensus as to whether they were flexible or stationary. A scale model of a neck, produced through 3-dimensional scanning and printing, will be used to establish approximate motion patterns of the neck, which will be tested by 3-dimensional motion analyses using FEA. Once the likely motion patterns are established, approximate hydrodynamic and mechanical constraints resulting from the motion will be modeled by equations, aided by Computational Fluid Dynamics, as well as flume experiments using scale models. A preliminary study shows that their neck and skull lengths present a uniform scaling pattern, presumably reflecting physical constraints arising from typical behavior of the animals. This observation and the obtained model equations will be combined to test the presence of physical constraints behind the evolution of the long neck. To establish the framework further, living cetacean specimens, for which material properties and vertebral motion range are measurable, will be studied in the same manner to verify the validity of the FEA motion analyses. Two Ph.D. students and up to 18 undergraduate students will be trained.