Bob Shadwick retired January 1st, 2022
Bob's notes from 1953-2023
In my academic research career, I’ve conducted field and lab research in animal biomechanics that focused on the circulatory and locomotor systems of a variety of animals including invertebrates, amphibians, reptiles, birds, and mammals. I have been fortunate in meeting and working with wonderful colleagues from Canada, USA, UK, Europe, and Australia. My career path has been somewhat random, mostly driven by curiosity, unexpected discoveries, good luck, hard work, and tireless support from my family.
I was born and grew up in London Ontario, went to schools named after famous men (Winston Churchill, St. George, Egerton Ryerson, Adam Beck) and learned to skate on a backyard ice rink. My early interests were canoeing, bird watching, fishing, and building things. My parents came from English, Irish and German farm families who had lived in Ontario for many generations, even before confederation. Growing up, my aspiration was to become a carpenter but I was encouraged to go to university and pursue a “white-collar” profession, a path that none of my ancestors had taken. I enrolled in a Zoology Honours program at UWO and met my future wife Kristina on a camping trip in 1974 with the undergrad Biology Club. For the Honours thesis I studied insect physiology, specifically the role of cyclic-AMP on controlling release of blood sugar from the fat-body. In my final year I took a course in Animal Mechanics from the Biophysics Department, based on a fascinating book published by R. McNeill Alexander, and it really caught my interest. A field course on invertebrate zoology at St. Andrews NB provided the stimulus to study marine biology, and my honours advisor, John Steele, suggested I apply to work at Dalhousie or UBC for a Master’s degree. I corresponded with Ron O’Dor and John Gosline (both suggested by Steele) by mail and chose UBC, sight unseen.
Kristina and I packed our orange VW wagon and drove to Vancouver in the summer of 1976, got married and rented our first apartment right by the ocean on Pacific Street in the West End. My decision to join Gosline’s lab turned out to be a very significant event in my life. John was a new professor in Zoology who was already well-liked and recognized as an intellectual giant by his colleagues. He became my mentor and friend for four decades and was the most influential person in my life, outside of family. While I studied vascular elasticity in cephalopods, Kristina worked as a lab tech in Agriculture and later received an MSc in Food Science. She also grew cultures of Guinness yeast that helped fuel our home-brewing endeavors. I transferred to the PhD program after our discovery of a fibrous elastic protein in octopus and squid arteries. This was published as my first thesis paper in Science (1981). I met Mark Denny, another Gosline PhD student and Bill Milsom, a PhD student in Dave Jones’ lab. We became a life-long friends and colleagues. Denny helped me learn experimental techniques in viscoelasticity, and Milsom taught me some basic animal surgery techniques. We conducted some challenging experiments to measure blood pressures and flows in the giant pacific octopus, and played hockey with the Zoology grad student team, the “Friends of the Armadillos”.
Following my PhD completion, I decided to go to the UK where many of my ancestors had emigrated from and where my father had lived while serving in the Royal Canadian Air Force during World War II. I applied to study connective tissue proteins, specifically collagen with Allen Bailey who had discovered the biochemical structure and synthesis pathways of collagen covalent crosslinks. With a two-year Post-Doctoral fellowship (PDF) from the Natural Sciences and Engineering Research Council of Canada (NSERC), we moved to Bailey’s government lab at the Langford House estate, on the site of the Bristol University Veterinary School field station for 1983 and 1984. We lived in Somerset at a country manor home called Churchill Court with walled gardens, tennis court, ornate wrought iron gates and a spiral staircase in the clock tower that connected to our top floor flat in converted servants’ quarters. My goals were to learn how to identify and characterize collagen connective tissues in cephalopods, and spend some time at the University of Paris’s Laboratoire Arago in Banyuls in the south of France studying octopus blood vessels and enjoying the Mediterranean lifestyle. This opportunity was arranged by a Cambridge colleague, Martin Wells, who regularly spent his summers doing octopus research at Banyuls. This was an exciting period which included conferences and field work in the UK and Europe, lots of travel in rural Britain, and successfully fulfilling another goal which was to visit an average of at least one pub per day during the two years of our stay.
In 1985, with support from Brian McMahon and George Bourne, I moved to the University of Calgary as an NSERC University Research fellow and Assistant Professor of Biology. There I started supervising MSc students (Collen Pollock and Carol Gibbons) and began comparative studies of animal locomotion, specifically the structure and elasticity of mammalian leg tendons. Pollock showed that tendon properties were variable with age and the locomotor role of the particular muscle the tendons linked to. This led to a visit by Professor Alexander, who had inspired my undergraduate interest in Biomechanics and, subsequently, an invitation to conduct follow-up research in his lab at the University of Leeds where former lab-mate Edwin DeMont was working as a PDF. Gibbons learned how to cannulate arteries and explored the dynamics of blood flow in giant toads. Other highlights of the Calgary years were the birth of daughters Rebecca and Katherine, the 1988 Winter Olympics (including watching British ski jumper Eddie the Eagle and the Jamaican bobsleigh team) and the 1989 Stanley Cup win. I also began visiting the Bamfield Marine Station for teaching and research activities.
But a January job interview and subsequent offer of a position as professor of Marine Biology at the Scripps Institution of Oceanography in San Diego provided an opportunity to leave the frigid prairie and move to southern California. We added our son Erik and raised the young family in shorts and flip-flops year-round. This position provided access to a stellar assemblage of research colleagues and a chance to participate in field work on the swimming physiology of tunas in Hawaii, initiated by Jeff Graham. With support from the US National Science Foundation (NSF) and Scripps students we established a research program to explore the mechanical design of muscle and tendon complexes in tunas, a group of warm-blooded fishes regarded as supreme swimming machines. This involved setting up a tuna swimming facility at the National Marine Fisheries Lab in Honolulu where we worked for several years. Rich Brill, a former UBC PDF was the head of tuna research there. Added to this were collaborations with Andy Biewener (Harvard) and James Covell (UCSD) to measure tendon forces in swimming tuna, and with Doug Syme (Calgary) to study muscle contractile dynamics using live fibre bundles isolated from the aerobic and glycolytic muscles. With PhD students Heidi Dewar, Keith Korsmeyer, Torre Knower and PDFs Steve Katz and Chin Lai, we described the structural and functional connection between the anatomy, muscle dynamics and swimming kinematics that resulted in a series of definitive papers, including several in the Journal of Experimental Biology (JEB) and one that appeared in Nature (2001).
The logical extension of this work on tunas was a comparative study with warm-blooded lamnid sharks to explore the convergent evolution of muscle and tendon structure that enable the thunniform swimming mode in this distantly related group. Jeanine Donley joined the lab to work on muscle dynamics for her PhD, with help from Graham’s student Chugey Sepulveda. Sven Gemballa from Tubingen had produced some elegant work on the 3-D organization of tendons in several groups of fishes and was keen to collaborate on the lamnid shark project. Using the short-finned mako, available by angling offshore from Scripps, we found that this shark had extremely long tendons within the lateral musculature that linked the centrally located aerobic fibres to skin and caudal fin. These were functionally similar to, but anatomically distinct from, what had been described in tunas. The remarkable convergence in highly specialized anatomy and muscle dynamics was presented at a SICB conference by Donley, where a chance meeting with a Nature editor led to its publication in that journal (2004). This was followed by JEB papers and a detailed anatomical account (Journal of Morphology) with Gemballa and his PhD student Peter Konstantinidis. A final component of the research program was to study a cold-water lamnid, the Alaskan salmon shark, which can live for prolonged periods in near freezing water while maintaining internal muscle temperatures of nearly 20oC higher. A supplement from the NSF provided a memorable fishing trip in Prince William Sound, Alaska, with Diego Bernal, Donley and Syme during the 2004 Stanley Cup final that was nearly won by Calgary. A paper, showing that their aerobic muscles are so well adapted to work at these high temperatures that they can not actually contract fast enough or with enough power to swim at the cold ambient ocean temperatures where they live, was also published in Nature (2005).
A separate line of biomaterials research carried out at Scripps and with colleagues at the University of New Mexico (John Trotter and Tom Koob) was on the structure and mechanical properties of the collagenous tissues in echinoderms that have mutable tensile properties controlled by the nervous system. This unexpected and unusual trait is not known in any other animal phylum. Led by Greg Szulgit, this work comprised his PhD thesis (1998) and was published in the JEB. A related study with Herb Waite at UC Santa Barbara was on the egg capsule biopolymer of marine snails that exhibit yield-heal behaviour when over-extended that maintains capsule integrity and prevents rupture. Scott Rapoport’s research formed the basis of his PhD (2003) and appeared in JEB and Biomacromolecules. At the same time, Jennifer Nauen completed a PhD (1998) on the biomechanics of tail flipping locomotion in lobsters, which had the added benefit of providing some very tasty dinners.
In 1991 I was invited by Ron O’Dor to participate in a research expedition to the Azores to investigate the biology of a population of squid (Loligo forbesii) that attain body lengths of more than 1m. With PhD student Jenn Hoar, whose grandfather William had been UBC Zoology Head in the 1960’s, and Frank Carey (Woods Hole Oceanographic Institution) O’Dor planned to capture and attach radio tracking devices to these squid in order to find out what their daily movement and feeding patterns were. This was an emerging technology that was developed by O’Dor and Dale Webber that eventually turned into a commercial venture called Vemco, now a world leader in acoustic telemetry systems used by biologists. My assignment was to measure pressure profiles of the jet propulsion system powered by the body wall muscles. This involved fitting captive squids with pressure transducers in large seawater tanks with a makeshift electrical system that routinely gave us shocks each time we made contact with the water. The other obstacle was that the tracking equipment Carey had brought was not released from the Azorean customs office until a suitable “tip” was offered.
In spring 1994 we had a three-month family visit to Denmark, where I helped teach a fish locomotion course with John Steffensen. We had met John in 1985 at UBC when he was a PDF with Dave Randall. We stayed in an old thatch-roof cottage in a small farming village called Lille Lyngby, about 30km from the Helsingør Marine Biology Laboratory where the course was held. Rebecca had started Grade 1 so Kristina helped her do homework assignments and mailed them back to her teacher in San Diego. Katherine celebrated her 5th birthday with a traditional Danish party complete with flags. Erik was too young to remember the trip. We found out that in Denmark a Danish pastry is called a Wienerbrød (Vienna bread). John came to San Diego in 1996 with Elsebeth and daughter Kirstine. In the lab with James Covell at UCSD School of Medicine we perfected a technique with x-ray fluoroscopes and miniature gold bead markers to measure length changes in different layers of muscles in a mackerel while it was swimming in a water treadmill in the lab.
In 2003 a casual conversation with Scripps acoustician John Hildebrand, led to a change in my research direction to study biomechanics of baleen whales, the largest animals on earth. Hildebrand had designed digital tags to record vocalizations of fin whales during their engulfment, or lunge feeding, behaviour. The tags contained a hydrophone, a pressure sensor and tri-axial accelerometers; they were attached by suction cups on the whale’s back using a long pole during pursuit by a fast boat. It turned out that these whales actually can’t vocalize at depth due to lung collapse, but the other data represented a trove of information on the kinematics of lunge feeding. With Office of Naval Research support we recruited PhD student Jeremy Goldbogen (Jergold), and he and I joined the Hildebrand group on a whale survey expedition to the gulf of California on the Scripps research ship R/V New Horizon. We made well over 100 sightings of baleen whales, listened to deep swimming sperm whales with hydrophones, and searched almost unsuccessfully for elusive beaked whales. We also encountered our first group of blue whales in feeding mode while colleagues from Cascadia Research were deploying tags. Soon Jergold was busy analysing kinematic data and figuring out how to calculate swim speed from the turbulence noise on the hydrophone.
The initial paper on fin whales detailed the three dimensional motions involved, the number of lunges performed, and duration of each dive. This was a landmark study that set the stage for a series of papers on lunge feeding kinematics with Jergold, Hildebrand and colleagues that also included humpback and blue whales (JEB 2006, 2008, 2011, and others). The most striking results were that the engulfed water volume could be greater than the whale itself, and the dive duration was so very short for such large animals (only as long as for an emperor penguin which is 4000 times smaller than a blue whale). In addition, the number of lunges per dive decreased with increasing body size. This led us to speculate on the enormity of the energetic cost of the lunge feeding kinematics and the potential limitation on body size. We recruited Jean Potvin, a Québecois parachute physics specialist from St. Louis University to spearhead modelling the energetics of lung feeding based on the tag kinematics. The key to validation of Potvin’s models was that the predicted deceleration of the whale resulting from various water engulfment scenarios had to match the actual deceleration measured by the tags. Potvin’s models showed that the energetic cost was very large, increasingly so for larger species, and predicted that the maximum body size (i.e. at which the whale could only perform one lunge on a dive) was about 33m. This is close to the size of the largest blue whale ever measured. We also predicted that the mouth opening rate must be carefully controlled so that the velocity of the engulfed water would match the whale speed as the mouth was closed. This had important implications for two later projects on the biomechanics of the ventral groove blubber/muscle tissue.
John Gosline had invited me to apply for an NSERC Tier I Canada Research Chair in 2004 to be held in the Zoology Department at UBC, and he convinced his colleagues to support this endeavour. Of course I was very excited to accept the position and return to British Columbia with my family, minus Rebecca who headed to McGill as an undergraduate student. Katherine and Erik finished high school in Vancouver and then attended UBC for undergraduate degrees. With support from the Canadian Foundation for Innovation, NSERC and UBC, I established my new research lab and recruited trainees who worked on a variety of biomechanics topics, including fish muscle mechanics, whelk egg capsule protein fibres, woodpecker head banging, hydrodynamic modelling of lift-based thrust in fish tails, artery wall mechanics, (Trisha Armstrong, Micha Ben-Zvi, Carla Corbett, Wes Didier, Marc Delepine, Peter Dimoulas, Erica Ross, James Whale) as well as whale anatomy and biomechanics (Jergold, Daniel Field, Kelsey Gil, Sheldon Pinto, Marina Piscitelli, Nick Pyenson, J. Whale).
Gosline retired in 2008 and I launched a plan to recruit Doug Altshuler to fill the biomechanics position. For the interview visit I picked him up at the airport and went directly to what has since become one of our favourite hangouts; the Galley bar at Jericho Beach. This made a lasting impression and probably helped Altshuler decide to accept our offer. We became close friends and colleagues in many ways. He arrived in 2011 and we moved to renovated shared lab space with Gosline. Altshuler brought an exciting research program on hummingbird flight and ushered in the new era of Thursday biomechanics lab happy hour (called “Beak and Blowhole”) with excellent home brew provided by his student Benny Goller. Fridays often ended with the 3rd and 4th floor faculty (and sometimes our Dean, Simon Peacock) sampling scotch in the Dave Jones lounge.
After Gosline’s retirement his long-serving Research Associate, Margo Lillie, an expert on elastin and artery mechanics, joined our whale research team. We also added anatomical expert Wayne Vogl from the Faculty of Medicine whom I had met as PhD student in Zoology while we were teaching assistants in the comparative vertebrate anatomy course and he was completing his PhD on vascular anatomy in toothed whales. In 2009 we started a program of biomechanics and anatomy of fin whales with Icelandic colleagues (Kristján Loftsson, Dalli Halldórsson, Hannes Petersen), and other species that were recovered from strandings. This activity was generously facilitated by Stephen Raverty, a BC provincial veterinary pathologist and UBC Adjunct Professor who is our local expert on marine mammals. With Raverty’s tireless help and dissection skills we amassed a large collection of whale parts that formed the basis of several studies in functional morphology with implications for physiology.
Investigating the mandibular symphysis (the chin), where the unfused mandibles join, we discovered a large mechano-sensory organ, innervated by the mandibular nerve, and likely sensitive to internal pressure changes that occur as the jaws rotate during mouth opening. We proposed this provides a mechanism to sense and control the degree of opening during lunge feeding (Pyenson et al., Nature 2012). This was cited by Discover magazine as one of the top 100 scientific discoveries of 2012. Control of engulfed volume also depends on the rate of expansion of the ventral grooved blubber (VGB) and stretching of the subdermal muscle layers We determined that these muscles could accommodate the very large deformations observed with full engulfment, control expansion by actively resisting stretch, and shorten to aid the elastic recoil of the VGB and expel the water during filtration. Nerves within these muscle layers also turned out to be extremely extensible due to a high degree of folding in the rest state (Current Biology 2015, 2018). Pinto examined the microscopic structure of baleen plates and showed that the keratin base from which the baleen emerges during growth is a rubbery shock absorber. Piscitelli obtained a large number of whale lungs from strandings for comparative anatomy with CT scanning and biomechanical studies. Gil joined the necropsy team with Raverty and focussed on anatomical adaptations for breathing and swallowing, particularly in fin whales. She discovered the oral plug that prevents choking while swallowing underwater and how the fatty nasal plugs self-seal the airway when the whale is submerged (JEB, 2020, Curr. Biol., 2022).
Lillie showed that arteries within the thorax are exceptionally stiff-walled, and we postulated this could prevent vessel collapse as adverse pressure gradients occur during rapid depth changes. Follow-up work led by Lillie considered the role of the diaphragm and its vena caval sphincter in mitigating pressure pulsations in the abdomen and thorax that are generated by forceful swimming strokes while breath-holding (JEB, 2013, 2017, 2018). These studies led to a model of the hemodynamic role of vertebral and cranial vascular retia in whales that suggested these structures protect the brain from locomotion-induced pulsations of blood pressure and flow (Lillie et al., Science 2022).
We expanded into the realm of palaeontology in 2010 when Pyenson organized an expedition to Carmanah beach on the west coast of Vancouver Island, with Goldbogen and myself, to hunt for whale fossils that might be ancestors of extant mysticetes. We made several finds of interest so Pyenson, who had just started a job with the Smithsonian Museum, began the process of obtaining the permits and necessary equipment to recover specimens that were partially exposed on a fairly convenient intertidal bench. The return trip in 2012 had a larger team that included Katherine Shadwick for geological assistance. We successfully excavated and plaster-encased two aetiocetids, comprising skull, shoulder and vertebral bones, and sent them by helicopter to our van with trailer in Port Renfrew. They were then CT-scanned at UBC and shipped to the Smithsonian Natural History Museum to be prepared for display. In 2021 a cast of one of the specimens was received at UBC and will become part of an exhibit on whale evolution.
In 2012 Maria Morell Completed her PhD in Barcelona where she had studied microscopic cochlear cell damage in toothed whales caused by anthropogenic noise in the oceans. Through a contact with Raverty and support from NSERC Morell joined us as a PDF in 2013. She had developed an impressive technique to dissect the cochlea from the inner ear, image it by electron microscopy, and analyse the patterns of the ciliated receptor cells which are destroyed from over-exposure to sound waves specific to their individual frequency sensitivities. Morell formed an international network of collaborators who were able to provide preserved ear samples recovered from whale strandings in North America and Europe. She also worked with PhD student Piscitelli and native hunters in the Canadian Arctic to obtain fresh ear samples from harvested beluga whales. We recruited MSc student Cassandra Girdlestone to work with Morell to analyse ear damage in belugas and make a model to link to the affected hearing frequencies which change along the length of the cochlea. They also studied the morphology of the cochlear cells in ears from bats and rats to help create a frequency map that could be applied predictively to toothed whales.
In 2012 Steffensen invited me to go on a Danish expedition to study Greenland sharks, the oldest known vertebrate species. We flew to Reykjavik and sailed on the research ship Dana to Ammassalik Fjord on the east coast of Greenland for a 10-day trip. Using long lines, the largest fish hooks available, and rotten seal as bait we were able to catch several large sharks. Satellite transmitter tags were fitted to the dorsal fins with the hope that the sharks’ geographical movements over a period of several months could be determined, perhaps giving a clue as to where their reproductive grounds might be. Two other Greenland trips occurred: 2016 to Nuuk and Tunulliarfik fjord on the south west coast on R/V Sana and 2019 to the Danish Arctic station at Qeqertarsuaq on Disco Island along the central west coast. There we began studies of the structure and contractile properties of the heart and swimming muscles, and continued tagging efforts. These trips were challenging and interesting, with lots of fun and outstanding scenery including whales, glaciers and icebergs, but no polar bears.
After serving more than a decade, Bill Milsom retired as Zoology Department Head in 2013, leaving big shoes to fill. His masterful skills as an administrator made the job look easy, and I was persuaded, facilitated by Altshuler, to take on the challenge for a five-year term, 2013-2018. Altshuler joined the administrative team as Grad Advisor, and thus began our ritual of regular “cone of silence” meetings to discuss departmental issues. My first action as Head was to set a countdown clock on my computer so that I could keep a close eye on the approaching end date in 2018. Since our Dean of Science had the same end date for his appointment I amused him by frequently reporting our remaining time, to the minute, particularly on Friday afternoons. During these years, I came to appreciate how academically strong and collegial our department was, and the time actually passed with relatively few stressful events.
A chance meeting with long time colleagues Mark Denny and Donal Manahan at a bar during a conference in San Francisco resulted in an invitation to join them as an instructor for a training program sponsored by the NSF at the McMurdo Research station in Antarctica. In January 2018 we rendezvoused with 24 students in Christchurch New Zealand for an eight-hour flight south to Ross Island in McMurdo Sound on a C130 Hercules military transport airplane fitted with skis to land on the sea-ice runway. In addition to collecting fish and invertebrates from -2°C water for studies in the lab, we were allowed to visit the well-preserved 1902 Scott Discovery Hut, located at McMurdo Station and the 1911 Cape Evans hut (accessible by helicopter), the base camp for the ill-fated Scott expedition to the south pole. This was a remarkable experience and one that is only possible by special arrangement. Four weeks later we returned home via Christchurch after several weather delays. Unexpectedly, this trip qualified all members to receive the Antarctic Service Medal, awarded by the US Armed Forces and NSF for participants of any U.S. Antarctic expedition.
June 30 2018 was my last day as Head. In August I turned 65 and began winding down toward retirement. The first step was a one-year administrative leave of absence, followed by a 30 months on a reduced appointment. Kristina and I had a fun road trip to California and visited with Jergold and his group of whale researches at the Hopkins marine Station in Monterey Bay. I was able to accompany them on two outings to help tag a group of feeding humpbacks, and to recover a tag from one blue whale. Our drive home took us through the coastal redwood groves in Northern California where we saw some of the tallest trees on earth.
2019 was the last year of normalcy before the Covid lockdown, and it began on a high note. I attended the annual meeting of the Canadian Society of Zoologists and was honored to receive the FEJ Fry Medal, presented by my good Kiwi friend Brent Sinclair, the Society president. It was awarded for “outstanding contributions to knowledge and understanding of an area in zoology”. This involved giving a special research lecture to the conference, followed by a visit to a local brewery where we celebrated while a stand-up comedian made fun of me wearing my suit and medal. Fortunately, Sinclair mounted a robust defense on my behalf.
The end of year highlight was a marine mammal conference in Barcelona which I attended with Raverty, Lillie and Gil. Former lab members Piscitelli and Morell joined us for what turned out the be the last in-person conference for three years. While teaching my biomechanics class in 2020 we were locked down and the course finished with on-line lectures. That continued for the following year. Long time Research Associate Lillie retired in 2020, and the last PhD student Gil defended in 2021 and stayed on as a PDF for one year. Francesca Ciocca began an MSC with Altshuler on bird wing shape control and I agreed to co-supervise. Retirement the end of 2021 was followed by a wonderful Zoology retirement party in May 2022 at the Steamworks Brewery on the downtown Vancouver waterfront. Everyone had a good laugh at the old photos and stories. In addition to the local friends and colleagues I was very pleased to welcome out of town guests, Pyenson (D.C.), Goldbogen (CA), Pinto, (AB) Matt Regan (PQ), and new PDF Bob Cieri who had just arrived from Australia with NSF funding to do computer modelling of airflow patterns in digitally reconstructed models of whale lungs. This is an exciting project that aims to explain how large baleen whales can move so much air in and out of their lungs so quickly. We are pursuing this along with long-time colleagues Milsom and Vogl and help from Kelsey Gil. We aim to have one more research field trip to Iceland in 2023.