Conservation Science – Its Roots & Future at UC San Diego
Most people, when hearing of biology at UC San Diego, think of the outstanding basic biology and biomedical research programs. But scientists in the Ecology, Behavior, and Evolution Section of the Division of Biological Sciences have long stood at the forefront of research in their respective fields. In fact, conservation biology as we know it today first came into existence at UCSD in the late 1970’s.
The practice of nature conservation was not new, thanks to prominent figures such as Theodore Roosevelt and John Muir, but prior to the 1970’s, conservation was focused solely on real-world applications such has hunting and fishing limits and the placement of duck nesting boxes. Wildlife conservation was not science; there was very little quantification, theory, or hypothesis testing.
That all changed dramatically when Michael Soulé, then an associate professor of biology at UCSD, and his graduate student, Brian Wilcox, organized the First International Conference on Conservation Biology in the fall of 1978. The meeting marked the first use of the term “conservation biology” and the birth of a new interdisciplinary research field.
Soulé’s inspiration for bringing science to conservation came to him while on sabbatical at the Commonwealth Science Industrial Research Organization in Sydney, Australia in 1974. Sir Otto Frankel, a prominent plant geneticist who was tinkering around with a new concept he termed “genetical conservation,” was impressed with Soulé’s work on the genetics of island lizards and invited Soulé to give a talk.
Once Soulé returned to UCSD, he began to think seriously about combining conservation with several sciences he thought could better inform conservation activists. Says Soulé, “We were concerned that the scientific findings coming out of ecology, biogeography, and population genetics were not percolating into the mainstream conservation organizations.”
Backed by an NSF grant to fund their new idea, Soulé and Wilcox assembled a group of prominent scientists from diverse fields such as population genetics, ecology, evolution, and reproductive biology. The participants included Edward Wilson, Paul Ehrlich, Thomas Lovejoy, and Jared Diamond, all of whom were giants in their respective fields and went on to play pivotal roles in conservation.
According to David Woodruff, a professor of biology at UCSD who joined the faculty shortly after the conference, “The motivating factor was a realization that wildlife was entering a period that probably would constitute a mass extinction.” A scientific approach was necessary to make wildlife conservation more effective.
The conference brought together two ideas that would go on to shape much of modern conservation biology: the theory of island biogeography and the concept of the minimal viable population.
The theory of island biogeography had recently been established by Edward Wilson and Robert MacArthur. In short, the theory states that the number of different species on an island is determined by the size of the island and the rates of extinction and immigration of new species.
Island biogeography became important to conservation when scientists began thinking of the remaining undeveloped lands as islands of nature in the midst of human development. According to Ted Case, a population biologist who recently retired from UCSD, “The phrase ‘habitat fragmentation’ came about from applying what was known of real islands to virtual islands created by man-made modification of the landscape.”
Although the implications of island biogeography for conservation were hotly debated for some time, a consensus is beginning to emerge. “It’s becoming clear that as you look at fragmented ecosystems, species do begin to disappear. Exactly how fast and which particular species go first is very complicated, but nonetheless, fragmentation of ecosystems is in general bad for diversity,” says Chris Wills, the only EBE faculty member currently at UCSD who was present when the first conservation biology conference was held.
The sharp increase in extinction rates that had many biologists worried could now be explained as a result of habitat fragmentation. Efforts to prevent this extinction centered on the idea of a minimal viable population, a topic widely discussed at the conference in 1978.
Inbreeding is bad for a population; it increases the chances of lethal genotypes coming together in an individual. If a population becomes too small, inbreeding is unavoidable and can lead to a rapid decline of a species. The minimal viable population is the smallest number of individuals in a species needed to provide the species with enough genetic diversity to healthily reproduce, as well as withstand natural disasters and other random events.
With the minimum viable population as a starting point, conservation biologists developed methods of population viability assessment to calculate risks and timelines of extinction and the number of individuals necessary to assure a sustainable population for a given length of time. Michael Gilpin, who also recently retired from UCSD, was one of the pioneers of these methods and worked closely with Michael Soulé during those early years of conservation biology.
Two years after the First International Conference on Conservation Biology, Soulé and Wilcox compiled the presentations and papers of the conference into a textbook, Conservation Biology: An Evolutionary-Ecological Perspective. Informally known as “The Brown Book,” the text helped define the field of conservation biology. Armed with this knowledge of genetics, population biology, and ecology, conservationists were not only able to quantify which species were going extinct and how quickly but also to manage threatened populations more effectively.
In addition to editing two more textbooks on conservation biology, Soulé founded the Society for Conservation Biology in 1985, which is now one of the world’s fastest growing scientific societies, with more than 14,000 members. The journal Conservation Biology, which is published by the society, has emerged as one of the leading journals in the field.
Although Soulé left UCSD in 1979, others at UCSD continued to provide major contributions to conservation, including Ted Case, Michael Gilpin, Russ Lande, David Woodruff and Christopher Wills.
Woodruff developed practical methods to carry out genetic studies of animals in the wild. As wild animals are usually wary of humans or dangerous to humans, obtaining DNA samples presented a challenge. In the late 1980’s, Woodruff and his colleagues introduced methods of non-invasive genotyping based on shed hair, feathers and dung. This allowed them to characterize the genetic structure of populations of wild chimpanzees, elephants and endangered birds for the first time. They pioneered methods, now widely used, that permit investigators to census and sex animals without ever seeing them, and to monitor the genetic collapse of populations trapped in habitat fragments. Recently, Woodruff has turned his attention to the viability and sustainability of the 1,000 species in the San Diego Zoo’s collection.
The recent work of Chris Wills on tropical forest ecosystems is furthering the understanding of why habitat fragmentation is detrimental to the health of an ecosystem. His work suggests that organisms benefit from living in a diverse ecosystem, most likely because a wide variety of species can more effectively utilize an ecological niche. He and his colleagues have also found that as cohorts of trees in tropical forests become older, the commoner species in the cohorts die more quickly, helping to preserve diversity.
Recent additions to the biology faculty at UCSD are also conducting research that applies to conservation biology. According to associate professor David Holway, a common cause of extinction is invasion by an introduced species that forces native species out of their niche. Holway seeks to understand why some species are vulnerable to invasion and why other species are effective invaders. As a model system, Holway studies Argentine ants, a South American ant species currently invading much of Southern California and causing widespread ecological changes.
Assistant professor Walter Jetz takes a more macroscopic perspective. Jetz aims to understand the various environmental and energetic constraints that determine where on the globe particular species are able to live. His lab is focusing on terrestrial vertebrates, attempting to integrate the vast amount of available data into one cohesive model describing species distribution.
Two recently published studies, describing the distribution of bird and plant biodiversity across the globe, have provided never before seen glimpses of where different forms of life are found on the planet and how those patterns of distribution are changing. Jetz hopes his findings will help conservationists decide how to best utilize their limited resources.
This group has trained a number of successful scientists. Among those still close to home are adjunct professor Oliver Ryder, a geneticist, and Allison Alberts, the director of the San Diego Zoo’s Center for Research on Endangered Species. CRES, as it is known, was founded by another legend in the field of conservation, Kurt Benirschke, Emeritus Professor of reproductive medicine and pathology at UCSD. Finally, this survey would not be complete without mentioning adjunct professor David Western, Africa’s leading conservation ecologist. Western is the former director of the Kenya Wildlife Service and the Wildlife Conservation Society.
As in all of science, funding for conservation biology has become difficult to obtain in recent years. As public concern for the environment grows more focused specifically on global warming, conservation runs the risk of being overlooked. Even with the advances of modern conservation biology, the extinction rate continues to increase at an alarming rate. The work of biologists such as Woodruff, Wills, Holway and Jetz is essential to understanding how global warming will affect all life–plant, animal and human.
Just as private donations from alumni are one reason for the success of biomedical research at UCSD, Jetz hopes that alumni will help compensate for decreased government funding to keep alive the legacy of conservation biology at UCSD. Woodruff keeps larger dreams alive and hopes that one day a donor will be found to launch an international center for research and training in conservation science, to build on the field’s roots at UCSD.
Contributing Writer: Matthew Busse
From BioSphere Magazine, 2007-2008 issue, page 12.
