s8 Long Limbless Locomotors Over Land: The mechanics and biology of elongate, limbless vertebrate locomotion
(this symposia is to be presented January 6th, 2020 in Austin. See sicb.org – Austin symposia schedule for a full list of speakers)
What was the motivation to put together this symposia?
Limbless locomotion, particularly terrestrial limbless locomotion, has been chronically understudied for a long time. Terrestrial limbless species are thought by some to be so unusual or different that insights into their locomotion will provide little broader insight into locomotion, but this is far from the truth. Elongate limbless body plans are widespread in nature and frequently converged upon, with over a dozen independent convergences on functional limblessness in lizards alone. Indeed, the combined number of species of snakes (almost 3700 species) and of limbless squamates and amphibians is similar to the total number of non-flying mammals!
Despite their lack of legs, these animals move effectively through a wide range of habitats, and have a particular advantage in cluttered or confined environments such as dense vegetation, rocky terrain, narrow tunnels, and burrowing. While limbed animals must slow down as terrain increases in spatial complexity, limbless animals encountering increasing obstacle density can typically move faster. Furthermore, limbless animals often employ a variety of different locomotor modes specifically tuned to particular environmental challenges, such as concertina locomotion to move within narrow tunnels or sidewinding to cross desert sands.
Limbless locomotion has elicited interest from a wide range of disciplines. Evolutionary biologists and paleontologists seek to determine how limbless morphologies evolve across species, what selective forces lead to limblessness, and whether these evolutionary mechanisms are predictable and repeatable. Biomechanists examine the motions, forces, and muscular control of the diverse modes of limbless locomotion, seeking to understand the benefits, drawbacks, mechanisms, control and evolution of these behaviors. And roboticists seek to create bio-inspired “snakebots” which can harness the effectiveness of limbless locomotion for traversing cluttered terrains and confined spaces.
Interest in this field has been steadily growing since Mosauer’s Science paper in 1932, but in recent years the pace of publication has accelerated significantly. Increasingly powerful tools and technology enable more detailed examinations of limbless biomechanics, and a combination of fossil discoveries and improved phylogenies have shed increasing light on the origins and evolution of limblessness, as well as the high frequency of convergence. Advances in actuators and control are increasing the capability of “snakebots” to solve real-world problems (e.g. search & rescue), while biological data has proven to be a potent inspiration for improvements in snakebot control. Conversely, increasingly capable robots are becoming a model for testing form-behavior-function relationships in biology.
What is the purpose of the symposium?
While interest in limbless locomotion is increasing and collaborative work across disciplines has yielded novel insights, many topics of interest remain poorly understood or wholly unknown and researchers from disparate fields often work in isolation. The goal of this symposium is to identify major gaps in current knowledge and methods, to promote links between researchers across different fields within and beyond biology, and to coordinate efforts to move the field as a whole forward. To achieve this, we have brought together faculty from a range of backgrounds to present a rich assortment of talks and to spur future collaboration and innovation. By fostering cross-disciplinary research at this crucial stage, we can accelerate the development of all fields involved.
What future directions are you most excited about?
One of the most exciting developments in their field is how improvements in instruments, measurements, and robotics can all feed into each other to allow deeper understanding. New phylogenies which use molecular data and new techniques to resolve previously obscure relations provide us with deep insights into the evolution of these species. New instruments such as X-ray Reconstruction of Moving Morphology and contrast-enhanced CT scanning allow us to capture data which was previously invisible. Robotic models can explore the consequences of alternative behaviors and morphologies either not seen in biological systems or only present in extinct species. Even in isolation, these can be tremendously beneficial, but when used in combination via interdisciplinary collaborations, they can result in tremendous leaps in understanding.
s3 Symposia in focus: Biology at the Cusp: Teeth as a Model Phenotype for Integrating Developmental Genomics, Biomechanics, and Ecology
organized by Gareth J. Fraser and C. Darrin Hulsey
(this symposia is to be presented January 4th, 2020 in Austin. See sicb.org – Austin symposia schedule for a full list of speakers)
What was the motivation to organize this symposia?
The tooth as a model organ unites several fields of biology and therefore advances in the fields of tooth development, genomics, and functional ecology have been reflected in a recent surge of tooth-related research. We therefore decided that this would be a great time to showcase the diverse yet integrative biologies that use the tooth as a character for study. SICB, at its core, is a highly integrative international conference, and this therefore is an ideal venue for this particular symposium. We aimed to collect a diverse selection of the leading researchers in the field of tooth biology at a wide variety of career levels, with each participant bringing a unique approach to the study of teeth, either directly or indirectly. The focus of our symposium was to promote the exciting new developments in comparative and integrative tooth biology. This new wave of tooth biology has materialized in large part through the creative minds of early career scientists that bring a fresh assortment of tools to target important questions in the wider science of dental biology. Teeth are a vertebrate innovation and as a character unite the vertebrate clade from fishes to mammals. In addition, throughout the evolutionary history of vertebrates, teeth have been used to acquire and process food. This gives teeth a unique appeal for a model organ as it covers so many integrated fields of biology including development, evolution and trophic ecology. We therefore developed this symposium to reflect the diversity of research centered around the tooth and emergent vertebrate dentitions.
What were you looking forward to most about this symposia?
The opportunity to bring together so many tooth biologists working from such a diversity of perspectives and approaches is what we were looking forward to most. As attendees at the SICB meeting certainly appreciate: the power of integrative biology is often enhanced when we are able to learn about novel or complimentary approaches that can be used to tackle similar questions. Symposium such as ours that will all be focused on vertebrates and their teeth will allow everyone attending to gain integrative insights into cutting edge research in comparative biology. This symposium should provide an unparalleled opportunity for participants to gain knowledge about how mechanistic approaches in evolution, functional morphology, physiology, and developmental genomics could compliment each others’ research programs.
What future directions are you most excited about?
As the title of this symposium ‘Biology at the Cusp: Teeth as a Model Phenotype for Integrating Developmental Genomics, Biomechanics, and Ecology’ suggests, this collection of speakers highlights how wide-reaching and integrative the extended field of tooth biology is. So, the most exciting element of the future of this field is how far integrative collaborations can push or even break the boundaries of biological disciplines and galvanize crosscutting research. The tooth has become a central and uniting theme in biological research that links vast research themes from ecology, evolution, development, genomics and biomedical research. The tooth holds a unique position in biological research due to the fact that as a character it is a vertebrate innovation. But this character unites us all from fish to humans, and thus the conservation of development and form is major inspiration to our work as is the medical research facets of our work that offer a more direct impetus for a greater understanding of tooth form and function.
What do you hope attendees were able to take away from the Symposia?
We hope attendees come away with a more robust understanding of tooth biology and the many facets of biology that can be brought to together in dental research. Comparative tooth biology is also a field that has direct translational consequences for our understanding of human dentistry. Every day we are learning more about how processes such as tooth structure, tooth wear, and tooth replacement function all have diversified during vertebrate evolution history. This all can also provide valuable insight into human dental and craniofacial medicine. Additionally, because teeth are such an essential component of studies in disciplines as seemingly disparate as vertebrate paleobiology, ecology, and evolutionary developmental biology, an integrative understanding of dental phenotypes has far-reaching consequences for the Society as a whole. Whether attendees are more focused on basic research questions, applied human medicine, or interested in phenotypes that can be used to show the power of integration across disciplines for students in the classroom, we think this symposium will provide memorable insights for everyone.
