Renowned evolutionary biologist David Wake, the world’s leading expert on salamanders and among the first to warn of a precipitous decline in frog, salamander and other amphibian populations worldwide, died peacefully at his home in Oakland, California, on April 29.
The professor emeritus of integrative biology at the University of California, Berkeley, and former director of the campus’s Museum of Vertebrate Zoology (MVZ) was 84.
Wake died of organ failure after the reoccurrence of cancer, but until the week he died, his health problems did not keep him from publishing papers, conducting fieldwork, meeting with colleagues in person or on Zoom, and calling friends.
It was while pursuing a college degree in entomology that Wake became fascinated by salamanders. In search of insects, he’d turn over logs and leaf litter and discover these fascinating creatures.
“He starting seeing species of Plethodon, and then found Ensatina … and that was it. The end. He was captivated, and he tried to learn everything he could about these animals,” according to a 2017 perspective on Wake’s life written by former students Nancy Staub and Rachel Lockridge Mueller. Staub and Mueller are professors and salamander biologists at Gonzaga University and Colorado State University, respectively.
Wake abandoned entomology for the study of amphibians and reptiles, a field known as herpetology. He focused much of his attention on one species-rich, but poorly understood, family of mostly North and Central American salamanders, the lungless salamanders, Plethodontidae, many of which lead an entirely terrestrial existence and consequently do not lay eggs in water, like many other salamanders. His favorite among these were the Ensatina — a West Coast genus he studied, among many others, throughout his career.
Over his 57-year career, he discovered and described more than 144 new species of salamander and had four amphibian species named after him. But to Wake, salamanders were also a means of answering deep questions in evolution.
“He chose a particular lineage of organisms — in this case, the family Plethodontidae — and pursued it in all respects in order to understand how the group diversified and why it did the way it did. It was molecules to morphology to ecology to behavior to development, overlaid by taxonomy — his was a deliberate conviction that in order to really understand the evolution of organisms, you have to focus on a particular group and get to know it extremely well,” said James Hanken, director of Harvard University’s Museum of Comparative Zoology and one of Wake’s former students. “He is not the only person who chose that strategy. But what is unique is how successful Dave was at it. He took it to a level and a sophistication that few other people have done.”
Among the questions Wake addressed were how changes in development give rise to diversity, how geographic variation contributes to the formation of species, and convergent evolution — the way different lineages converge on the same morphological forms and how that happens.
“He is famous for describing ring species in a genus known as Ensatina. These are plethodontid salamanders in California that occur in a ring around the state, such that there is some gene flow between adjacent populations, but as you go around the ring, you get to a point where they are so different that they are reproductively isolated” and essentially separate species, said Michael Nachman, current director of the MVZ and a professor of integrative biology. “Salamanders were his love and passion, but he was really a deep thinker who used salamanders as an entry way to thinking about the biggest questions in evolutionary biology.”
As early as the 1970s, Wake began noticing that the sounds of frogs croaking at night in the Sierra Nevada had lessened, and in the 1980s, while searching for salamanders in Mexico, he noticed that once super-abundant species he had collected in the 1970s — at the time, species totally unknown to biologists — were no longer easy to find or completely missing from their previous habitat. Other herpetologists were reporting that frog populations worldwide also were declining, so he joined with several colleagues to bring the amphibian community together to discuss the threat. At their urging, the National Research Council quickly assembled a meeting in 1990 that drew widespread public attention to the problem — and an unaccustomed notoriety to Wake, as he fielded dozens of calls every week from reporters. The decrease in amphibians was the first of many documented declines in animal populations, including insects and birds.
“Amphibians are, in some respects, very sensitive to environmental perturbations, the canary in the coal mine,” Hanken said. “Dave and a small number of people really called the world’s attention to this phenomenon. He had a knack for seeing things on the horizon before other people did, of sensing trends or sensing important phenomena before others might have.”
Wake and others pinpointed one unexpected cause — the pathogenic chytrid fungus, which fueled a worldwide pandemic among frogs. This and the effects of global warming arrived on top of many other environmental insults — pesticides, parasites, habitat loss and the introduction of predators, such as trout in Sierra Nevada lakes — to depress global amphibian populations.
He began educating his students about the threat to amphibians, which eventually generated a clamor for a website to document the decline. In response, in 2000, he and several colleagues turned a class project into AmphibiaWeb, which has become a compendium of all known species worldwide — 8,330 as of May 3, with more than 40,000 photos — and a major resource for amphibian conservation. The site connects citizen scientists with researchers and spawned other efforts to create Internet sites cataloging the diversity of life on Earth before it goes extinct. Wake, who was the project’s director until his death, noted that the effort actually spurred the discovery of new amphibian species: There are now about twice as many known species as 20 years ago.
As director of the MVZ from 1971 until 1998, Wake shepherded the museum into the era of molecular genetics, establishing, with integrative biology professor and curator of mammals James Patton, a molecular evolution laboratory for use by all museum students, faculty and staff. Wake also encouraged the collection and freezing of DNA and tissue samples from animals, in addition to the skinned or pickled specimens typical of natural history museums. Such tissue has been critical in understanding how genes underlie evolutionary change.
“That was 1972, and that was the first molecular lab facility associated with any museum in the country,” said Patton, who arrived at UC Berkeley the same year as Wake and served as assistant museum director under him. “And the frozen tissue collection — since we were out collecting specimens, we decided we might as well collect tissues that could be used for biochemical purposes — was the first tissue collection associated with a museum anywhere in the world, as far as I am aware.”
Wake was on the committee that directed the renovation of UC Berkeley’s Valley Life Sciences Building and the movement of the MVZ collections into a new space there in the 1990s. He also was largely responsible for the museum’s current layout: a central collections area surrounded by faculty and student offices, a layout that facilitates interactions among the researchers. Nachman compared Wake’s impact on the museum to that of biologist Joseph Grinnell, who founded the museum in 1908 and created the modern concept of a natural history museum as a resource for generations of biologists.
“From my vantage point, David Wake’s influence was as great (as that of Grinnell),” said Nachman. “He is, without question, the only other director in the MVZ since its inception to have the kind of influence that Grinnell had on this institution.”
From entomology to herpetology
David Burton Wake was born on June 8, 1936, in Webster, South Dakota, and spent his adolescence in Pierpont, a town of a few hundred people. He was the grandson of Norwegian immigrants — Wake’s grandfather, Henrik Martinus Solem, was the first person to earn a college degree in the Dakota Territories. Wake’s mother, Ina Solem Wake, earned a college degree, as well, which was unusual for women of that era, and she groomed her son to follow in her family’s footsteps. She was a school teacher during the Depression; Wake’s father, Thomas, sold hardware and farm implements. The family moved to Tacoma, Washington, in 1953, where Wake finished high school.
Wake’s grandfather, an amateur botanist, instilled in him a love of nature, which he took with him to Pacific Lutheran College (now University) in Tacoma, from which he graduated in 1958 with a B.A. in biology, magna cum laude. His interest had shifted to entomology, and, in his senior year, to salamanders. At the encouragement of his entomology professor, he applied to graduate school in herpetology and was accepted by the University of Southern California, where he completed his Ph.D. in biology in 1964. He wrote his master’s and doctoral theses on the Plethodontidae.
In 1962, he married a fellow student at USC, Marvalee Hendricks, who abandoned her idea of becoming a medical doctor to become an evolutionary biologist and, later, a UC Berkeley professor of zoology and founding chair of the Department of Integrative Biology.
Wake joined the faculty of the University of Chicago in 1964, but was invited to join the UC Berkeley zoology department in 1969 as associate professor and associate curator of herpetology in the MVZ. He published more than 400 papers, 160 since his retirement in 2003, when he became a Professor of the Graduate School.
“Dave was a towering figure in evolutionary biology and herpetology and trained generations of students, including many leaders in the field today,” Nachman wrote on the MVZ website. “His deep wisdom, gentle demeanor and friendship were an inspiration to all.”
Patton echoed Nachman’s sentiments.
“They do not make people like David anymore, with his combination of integrity, ethics, drive and passion for sharing,” he said.
Upon full retirement as professor emeritus in 2016, Wake received the Berkeley Citation, campus’s highest honor for a faculty member. He also was a member of the National Academy of Sciences, American Philosophical Society and American Academy of Arts and Science. Among his honors were the Fellows Medal of the California Academy of Sciences, Joseph Leidy Medal of the Academy of Natural Sciences in Philadelphia and the Grinnell Medal from the MVZ. He served as president of the Society for the Study of Evolution, American Society of Naturalists and American Society of Zoologists.
Wake is survived by his wife, Marvalee Wake, now a UC Berkeley professor emerita of integrative biology, son, Thomas, a zooarcheologist at UCLA, and one grandchild.
FOR MORE INFORMATION
- Dinosaurs’ loss was frogs’ gain (2017)
- Newly discovered salamander species, world’s smallest, already endangered (2016)
- Scientists urge ban on salamander imports to fend off new fungus (2015)
- Despite global amphibian decline, number of known species soars (2012)
- Scientists document salamander decline in Central America (2009)
- Global warming sends salamanders packing (2007)
- Discovery of American salamander in Korea tells 100 million-year-old tale (2005)