From morphology to functionality

To functionally correlate bivalve (shell) forms and (shell) sculptures with sediment types and burrowing techniques, evolutionary computation, robotics, paleontology, neontology, and sedimentology are combined to develop a burrowing simulation as well as an autonomously burrowing robot.

Under the direction of Pfeifer, the Artificial Intelligence Laboratory of the University of Zurich acquired knowledge in the development of different kinds of robotic applications and the simulation of real-world processes. In the field of evolutionary computation, Eggenberger further investigated biological mechanisms that enable a modular robotic system to assemble and repair itself. In paleontology, Schatz was able to provide new insights into taphonomy, morphology, numeric systematics, biostratigraphy, paleobiogeography, paleoecology, and evolution of Mesozoic mollusks. One focus of his research lay on the interaction of functionality and morphogenesis of mollusk shells, shell structures and environment. Eggenberger and Schatz have established a successful collaboration between evolutionary computation and paleontology by elaborating a morphogenesis simulation. They gathered experience in dealing with the modeling of a (fossil) organism, the physical modeling of a granular medium, and a genetic regulatory network, whose parameters are evolved by an artificial evolutionary system and control modeled cellular mechanisms. This collaboration has improved our understanding of evolutionary processes, optimized computer simulations in the field of genetic regulatory networks, and yielded the possibly first metazoan sexual dimorphism in the history of life.

The knowledge acquired in the previous collaboration is transferred to the development of a bivalve burrowing simulation and an autonomously burrowing robot. The burrowing simulation consists of models of recent and fossil bivalve species, a model of a granular medium (sandy sediment), a model of the bivalve-sediment interactions, and a burrowing simulation controlled by a genetic regulatory network and evolved by an artificial evolutionary system. The autonomously burrowing robot is used to test the physical adequacy of the bivalve-sediment-interaction model and to calibrate its physical properties. After testing the biological significance of the burrowing simulation, we investigate the functional correlations between (shell) forms and (shell) sculptures with sediment types and burrowing techniques. The resulting correlations are then used to investigate the paleoecology of the modeled fossil bivalve species based on their shell morphologies.

Models of bivalve shells and sandy sediments as well as burrowing robots exist already – but have never been combined. The models of bivalve shells so far focus on morphogenesis, ontogeny, and pigmentation patterns. The burrowing robots are used to investigate the influence of the shell morphology on burrowing. In this project, we propose to increase the complexity of these different jigsaw pieces and to combine them in an integral whole. By combining the modeled bivalves with the modeled sandy sediment generating a bivalve-sediment-interaction model, by testing its physical adequacy, and by calibrating its the physical properties by using real-world data acquired using an autonomously burrowing robot, the reciprocal coherence of the model and the real world could be investigated. Finally, we will be able to investigate the functional interaction between (shell) sculptures, sediment types, and burrowing techniques by using the burrowing simulation. This will broaden our understanding of shell functionality and (paleo-) eocology of bivalves and of burrowing organisms in general. By nvestigating the functionality of aberrant shell forms and sculptures of extinct species, we could extend the field of bionics. In addition, geologists gain a tool to bypass diagenetical shortcomings of sediments (e.g. sorting processes, particle solutions, compaction, cementation) and to reconstruct the primary sediment conditions (e.g. water saturation, grade of compaction) of lithological units bearing endobenthic fossils. We expect that the investigated effects of different shell forms and sculptures on moving the shell through the sediment and anchoring the shell in the sediment could obtain importance in engineering by yielding new insights into drilling and anchoring in soft sediments. For evolutionary computation, this type of interdisciplinary collaboration
will lead to a refinement of the methods used in artificial evolution, especially in the subfield of embryogenic evolution. By validating the biological significance of the simulations in artificial evolution with real-world data found in recent as well as fossil bivalve species, the current embryogenic methods will be improved. Further, the collaboration with specialists in natural evolution will give an important feedback for the improvement of control methods of modular robots. Based on the results generated in this project, further projects could focus on the evolutionary constraints the bivalves faced in phylogeny or the matching of trace and body fossils.

This is an SNF-Project.