{"643751":{"#nid":"643751","#data":{"type":"news","title":"Snake Micro Scales Reveal Secrets of Sidewinding and Slithering","body":[{"value":"\u003Cp\u003EThe mesmerizing flow of a sidewinder moving obliquely across desert sands has captivated biologists for centuries and has been variously studied over the years, but questions remained about how the snakes produce their unique motion. Sidewinders are pit vipers, specifically rattlesnakes, native to the deserts of the southwestern United States and adjacent Mexico.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EScientists had already described the microstructure of the skin on the ventral, or belly, surface of snakes. Many of the snakes studied, including all viper species, had distinctive rearward facing \u0026ldquo;microspicules\u0026rdquo; (micron-sized protrusions on scales) that had been interpreted in the context of reducing friction in the forward direction\u0026mdash;the direction the crawling snake\u0026mdash;and increasing friction in the backward direction to reduce slip.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EConsidered through the lens of a sidewinder\u0026rsquo;s peculiar form of locomotion, however, it seemed that these microspicules would not function in the same manner. But no one had examined the microstructure of sidewinders, nor of a handful of unrelated African vipers that also sidewind.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EWorking with naturally-shed skins collected from snakes in zoos, researchers used atomic force microscopy to visualize and measure the microstructures of these scale protrusions in three species of sidewinding vipers as well as many other viper species for comparison. The results of the research, published this week in the journal \u003Cem\u003EProceedings of the National Academy of Sciences\u003C\/em\u003E, found that indeed the sidewinders have a unique structure distinct from other snakes.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe microspicules were absent in the African sidewinding species and reduced to tiny nubbins in the North American sidewinder. All three snakes also had distinctive crater-like micro-depressions producing a distinctive texture not seen in other snakes.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Ca href=\u0022https:\/\/physics.gatech.edu\/user\/daniel-goldman\u0022\u003EDaniel Goldman\u003C\/a\u003E, Dunn Family \u003Ca href=\u0022http:\/\/physics.gatech.edu\u0022\u003EProfessor of Physics\u003C\/a\u003E at the Georgia Institute of Technology, and \u003Ca href=\u0022http:\/\/www.physics.emory.edu\/home\/people\/bios\/rieser-jennifer.html\u0022\u003EJennifer Rieser\u003C\/a\u003E, working as a postdoctoral researcher in Goldman\u0026rsquo;s group and currently an assistant professor in the \u003Ca href=\u0022http:\/\/physics.emory.edu\u0022\u003EDepartment of Physics\u003C\/a\u003E at Emory University, developed mathematical models to test how both the typical texture of rearward-directed microspicules and spicule-less cratered texture function as snakes interact with the ground. The models revealed that the microspicules would actually impede sidewinding, explaining their evolutionary loss in these species.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe models also revealed an unexpected result that microspicules function to improve performance of snakes that use lateral undulation to move. Lateral undulation is the typical side-to-side mode locomotion used by the majority of snake species. \u0026ldquo;This discovery adds a new dimension to our knowledge of the functionality of these structures, that is more complex than the previous ideas,\u0026rdquo; said \u003Ca href=\u0022https:\/\/zooatlanta.org\/leader-expert\/joe-mendelson-phd\/\u0022\u003EJoseph Mendelson\u003C\/a\u003E, director of research at \u003Ca href=\u0022https:\/\/zooatlanta.org\/\u0022\u003EZoo Atlanta\u003C\/a\u003E and adjunct associate professor in the Georgia Tech School of Biological Sciences.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe models indicate that the microspicules act a bit like corduroy fabric. \u0026ldquo;Friction is low when you run your finger along the length of the furrowed fabric\u0026mdash;consistent with previous work\u0026mdash;but the furrows produce significant friction when you move your finger sideways across the fabric texture,\u0026rdquo; said Goldman. The functionality of the distinct craters remains a mystery.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe findings could be important to the development of future generations of robots able to move across challenging surfaces such as loose sand. \u0026ldquo;Understanding how and why this example of convergent evolution works may allow us to adapt it for our own needs, such as building robots that can move in challenging environments,\u0026rdquo; Rieser said.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EIn terms of anatomy, this was a classic example of convergent evolution between a pair of snake species in Africa and a very distantly related snake in North America, Mendelson noted. Biogeographic reconstructions conducted by Jessica Tingle, a doctoral student at University of California Riverside, indicated that the African snakes are evolutionarily much older than the North American sidewinder, suggesting that the sidewinders represented an earlier phase in adaptation for sidewinding.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ETai-De Li, then at Georgia Tech in the lab of Prof Elisa Riedo and now at the City University of New York, did the AFM measurements.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDrawing from the fields of evolutionary biology, living systems physics, and mathematical modelling, the team produced a study that explains some aspects of what these microstructures on the bellies of snakes do and how they evolved in snakes.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026ldquo;Our results highlight how an integrated approach can provide quantitative predictions for structure-function relationships and insights into behavioral and evolutionary adaptions in biological systems,\u0026rdquo; the authors wrote.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cem\u003EThis research was supported by the Georgia Tech Elizabeth Smithgall Watts Fund; National Science Foundation Physics of Living Systems Grants PHY-1205878 and PHY-1150760; and Army Research Office Grant W911NF-11-1-0514. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the sponsoring agencies.\u003C\/em\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECITATION\u003C\/strong\u003E: Jennifer M. Rieser, Tai-De Li, Jessica L. Tingle, Daniel I. Goldman, and Joseph R. Mendelson III, \u0026ldquo;Functional consequences of convergently evolved microscopic skin features on snake locomotion.\u0026rdquo; (\u003Cem\u003EProceedings of the National Academy of Sciences\u003C\/em\u003E, 2021)\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EResearch News\u003Cbr \/\u003E\r\nGeorgia Institute of Technology\u003Cbr \/\u003E\r\n177 North Avenue\u003Cbr \/\u003E\r\nAtlanta, Georgia\u0026nbsp; 30332-0181\u0026nbsp; USA\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contact\u003C\/strong\u003E: John Toon (404-894-6986); (jtoon@gatech.edu).\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EThe mesmerizing flow of a sidewinder moving obliquely across desert sands has captivated biologists for centuries and has been variously studied over the years, but questions remained about how the snakes produce their unique motion. Sidewinders are pit vipers, specifically rattlesnakes, native to the deserts of the southwestern United States and adjacent Mexico.\u003C\/p\u003E\r\n","format":"limited_html"}],"field_summary_sentence":[{"value":"The mesmerizing flow of a sidewinder moving across desert sands has captivated biologists for centuries, but questions remained about how the snakes produce their unique motion."}],"uid":"27303","created_gmt":"2021-02-02 01:15:39","changed_gmt":"2021-02-09 20:07:08","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2021-02-01T00:00:00-05:00","iso_date":"2021-02-01T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"643748":{"id":"643748","type":"image","title":"Microstructure of snake belly scales","body":null,"created":"1612227536","gmt_created":"2021-02-02 00:58:56","changed":"1612227536","gmt_changed":"2021-02-02 00:58:56","alt":"Microscope image of rattlesnake scales","file":{"fid":"244398","name":"lance-headed.jpg","image_path":"\/sites\/default\/files\/images\/lance-headed.jpg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/lance-headed.jpg","mime":"image\/jpeg","size":762089,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/lance-headed.jpg?itok=gdWZKxFR"}},"643749":{"id":"643749","type":"image","title":"Sidewinder in sandy arena","body":null,"created":"1612227616","gmt_created":"2021-02-02 01:00:16","changed":"1612227616","gmt_changed":"2021-02-02 01:00:16","alt":"Sidewinder snake in sandy arena","file":{"fid":"244399","name":"sidewinder-snake.jpg","image_path":"\/sites\/default\/files\/images\/sidewinder-snake.jpg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/sidewinder-snake.jpg","mime":"image\/jpeg","size":1150070,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/sidewinder-snake.jpg?itok=NPz7tSJS"}},"643750":{"id":"643750","type":"image","title":"Sidewinder snake microstructures","body":null,"created":"1612227723","gmt_created":"2021-02-02 01:02:03","changed":"1612227723","gmt_changed":"2021-02-02 01:02:03","alt":"Microscales of sidewinder snakes","file":{"fid":"244400","name":"sidewinder-scales.jpg","image_path":"\/sites\/default\/files\/images\/sidewinder-scales.jpg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/sidewinder-scales.jpg","mime":"image\/jpeg","size":804673,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/sidewinder-scales.jpg?itok=Wcx36_T-"}}},"media_ids":["643748","643749","643750"],"groups":[{"id":"1278","name":"College of Sciences"},{"id":"1188","name":"Research Horizons"},{"id":"126011","name":"School of Physics"},{"id":"1275","name":"School of Biological Sciences"}],"categories":[{"id":"135","name":"Research"},{"id":"146","name":"Life Sciences and Biology"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"169001","name":"Snake"},{"id":"169681","name":"sidewinder snake"},{"id":"186899","name":"snake scale"},{"id":"186900","name":"pit viper"},{"id":"186901","name":"microspicules"},{"id":"2352","name":"robots"},{"id":"166937","name":"School of Physics"},{"id":"166882","name":"School of Biological Sciences"}],"core_research_areas":[{"id":"39441","name":"Bioengineering and Bioscience"},{"id":"39521","name":"Robotics"}],"news_room_topics":[{"id":"71911","name":"Earth and Environment"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EJohn Toon\u003C\/p\u003E\r\n\r\n\u003Cp\u003EResearch News\u003C\/p\u003E\r\n\r\n\u003Cp\u003E(404) 894-6986\u003C\/p\u003E\r\n","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}