AUTHOR COMMENTARIES - 2009
August 2009

	Terrie Williams Featured Scientist Interview
	In a recent analysis of data from Essential Science IndicatorsSM from Thomson Reuters, the work of Dr. Terrie Williams was recognized as having the highest percent increase in total citations in the field of Plant & Animal Science for the period from December 2008 to February 2009. Currently, in this field, her citation record includes 17 papers cited a total of 524 times.

Dr. Williams is Professor of Ecology and Evolutionary Biology, as well as the Principal Investigator of the Mammalian Physiology Lab, at the University of California, Santa Cruz.

Please tell us a bit about your educational background and research experience—particularly what drew you to your current field.

My education was initially in medicine. At Rutgers University I switched from Human Physiology to Comparative Exercise Physiology for my Ph.D. when I found that animals were capable of extraordinary feats of athleticism and disease resistance—at least compared to the human animal. What I found most fascinating was that wild mammals, including mink, cheetahs, seals, and whales, accomplished these feats with the same mammalian tissue building blocks as ourselves. Yet, how do dolphins cruise easily at speeds that would earn an exhausted Michael Phelps a gold medal in the Olympics? How do Weddell seals avoid hypoxic brain damage or shallow water blackout when holding their breath for over an hour?

Not only do the answers to these questions allow us to predict the ability of these animals to survive in a rapidly changing world, they direct us to new avenues of research that will enable humans to live longer and perform better. This is already beginning to happen. One example is the new swim suits that enabled athletes to break so many speed records in the Beijing Olympics: many of the hydrodynamic and anatomical features mimicked those of dolphins. Imagine using 50,000 million years of waterproofing evolution of marine mammals to prevent hypoxic injury due to stroke or cerebrovascular insufficiency in humans. The solutions are there if only we had a better understanding of the biology of the animals around us.

Based on your list of highly cited papers, you work appears to focus on both the mechanics of diving in marine mammals as well as energetics and predator-prey relationships. Would you say this is a fair assessment?

The list of cited papers does seem somewhat eclectic. But the common theme is "survival." We've taken the next step from Knut Schmidt-Nielsen's question, "How do animals work?" to try to answer, "How do animals survive?" The energetics of an animal is the bottom line: are there sufficient resources in an environment and is the animal efficient enough at obtaining those resources that it will have enough energy to maintain its biological functions? Knowing energetic costs, because it is the common currency, enables us to inter-connect the physiological limitations of a wild species with the ecosystem in which it lives.

Today more than ever, it is important to understand this connection; these papers try to address that. Understanding the physiological limitations of a species gives us great predictive power for assessing the impacts of global warming. Unfortunately, our knowledge of even the basic physiological attributes of most wild mammals is poor. In view of this, the fact that over 25% of mammals are threatened with extinction, according to the International Union for Conservation of Nature (IUCN), is not surprising.

One of your most-cited papers has to do with diving: the 2000 Science paper, "Sink or swim: Strategies for cost-efficient diving by marine mammals" (Williams TM, et al., 288[5463]: 133-6, 7 April 2000). Would you talk a bit about this study—what you set out to find, what the results were, and why the paper is significant?

This was one of those science "Ah HA!" moments. My colleagues and I had been placing miniaturized video cameras on marine mammals to monitor their underwater behavior. I was interested in observing how the animals swam, so I convinced the team to deploy one of the cameras backwards, facing the tail. When we got the tapes back, we saw long periods of simply nothing. The flippers of the seals weren't moving for minutes at a time—it could have been a still photograph.

By pairing the video with the dive recorder data I realized that the animals were actually dropping like rocks through the water column, they were gliding instead of stroking. Suddenly, we understood a major trick that marine mammals use to conserve oxygen when they dove. We repeated this on Weddell seals in the Antarctic, elephant seals in California, bottlenose dolphins in Hawaii, and blue whales in the Pacific Ocean.

The blue whale video was especially interesting. On first pass it appeared that nothing was recorded in terms of their swimming movements. Then it occurred to me that perhaps the problem was the opposite as that for assessing hummingbird wing movements. Instead of slowing down the video as scientists do for hummingbird studies, I sped up the blue whale video. Now what we couldn't see with the naked eye was apparent on the fast playback, and we were able to detail the swimming and gliding patterns of the biggest animal on earth.

Another of your highly cited papers is the 2003 PNAS paper "Sequential megafaunal collapse in the North Pacific Ocean: An ongoing legacy of industrial whaling?" (Springer AM, et al., 100[21]: 12223-8, 14 October 2003). More recently, you published a paper in Proceedings of the Royal Society B-Biological Sciences, "Running, swimming, and diving modifies neuroprotecting globins in the mammalian brain" (Williams TM, et al., 275[1636]: 751-8, 7 April 2008). Would you tell our readers a little about these papers?

Both of these citations are "idea" papers, and took arduous paths to publication. Rather than limiting the scientific discussion to a simple reiteration of the results, the papers risk including a discussion of the implications of the research.

In the case of the PNAS paper, we cast the results in a historical context to ask the question, could industrial whaling from the 1950s have instigated a series of dramatic marine mammal population declines that is reverberating today in the North Pacific Ocean? A combination of energetic and ecological modeling based on the simple idea that animals have to eat regardless of whether you observe the predation events or not makes the scenario likely. Yet, it is impossible to prove; hence the paper and the ideas remain controversial.

Likewise, the Proceedings of the Royal Society paper moves beyond a simple comparison of globins in the cerebral cortex of wild mammals, and discusses the implications for human medicine. Moving beyond the rat, mouse, fly model is exceedingly difficult for this field, and the paper has taken its knocks. Ultimately, the paper simply says that marine mammals have figured out how to preserve brain function under extreme conditions of oxygen deprivation—in some species, like the bowhead whale, for lifespans of over 200 years. What if we were able to use the same types of mechanisms to prevent neural damage in victims of drowning or advanced age?

How have technological advances helped the progress of research in your field?

Miniature cameras and tiny deployable accelerometers have allowed us to travel with seals below the Antarctic sea ice, follow lions on a hunt across the African savannah, and dive with dolphins to remarkable depths. This ability to finally observe cryptic wild animals has provided remarkable insight on the challenges to survival for a wide variety of species. We are now pairing that physiological/behavioral information with functional genomics in which we will connect the genetic underpinnings with an animal's capabilities. It is definitely an exciting time for science.

What would you say is the most challenging aspects of your work? The most rewarding?

The most challenging aspect of this work is simply funding to support both the research and the students interested in becoming physiologists. Organismal biology in general and comparative physiology in particular have taken a back seat over the past decade to advances at the molecular level. With limited funding resources available to all scientists this has meant a severe shortage for research at the whole animal or organ function level. I feel that this has been to the detriment of wild animals—and as mentioned above—the IUCN red list of endangered species reflects this. When was the last you saw a published paper concerning the physiology or energetics of a wild African lion, red wolf, elephant, leopard, killer whale, or dolphin? Many of these large mammals are disappearing in our ignorance.

The rewarding aspect of this work is that there is an enormous potential to make a difference through science. To that end my colleagues and I have embarked on a new project at UC Santa Cruz. The vision is to build a new comparative biology research complex, the Center for Adaptive Physiology and Genomics, where we will link these two disciplines to explore the path from genes to enhanced physiological capabilities to human and animal health. This complex is designed to be a national resource for marine animal studies and genomic exploration that serves both resident and visiting investigators, a place where scientists can use their imagination to ensure the survival of all species, including themselves.

Terrie M. Williams, Ph.D.
Mammalian Physiology Lab
Ecology and Evolutionary Biology
University of California, Santa Cruz
Santa Cruz, CA, USA

KEYWORDS: ANIMAL PHYSIOLOGY, SURVIVAL, ENERGETICS, PHYSIOLOGICAL LIMITATIONS, MARINE MAMMALS, SWIMMING, DIVING, INDUSTRIAL WHALING, GLOBAL WARMING, BRAIN FUNCTION, OXYGEN DEPRIVATION, ENDANGERED SPECIES, COMPARATIVE BIOLOGY, CAMERAS, ACCELEROMETERS.