Exotic Species, Locales All In Day's Work For Conservation Biologists

Traveling to the ends of the earth in pursuit of biological quarry is not part of the job description for the average molecular biologist. But for anthropologist Don Melnick, going to work means trekking through the jungles of Southeast Asia for blood samples from the Javan silvery gibbon and other endangered animals. And the jobs of geneticist John Avise and biologist Brian Bowen entail long nights on tropical beaches waiting for nesting sea turtles. The following are the top ecology journals in which scientists who use molecular techniques to study conservation biology publish, although such articles also appear in other types of publications. The journals are ranked according to their impact, which is calculated by dividing 1993 citations to a journal's 1991 and 1992 papers by the number of papers it published in this two-year period. Also shown are the journal's 13-year impacts, calculated by dividing the number of citations from 1981 through 1993 to a journal's 1981 papers by the number of papers published in 1981. 2-Year 13-Year Rank Journal Impact Impact 1 Annual Review of Ecology and Systematics (1970) 4.3 91.0 2 Ecological Monographs (1931) 4.1 51.0 3 Trends in Ecology & Evolution (1986) 3.5 NA 4 Evolution (1947) 2.8 27.2 5 Advances in Ecological Research 2.7 NA (1962) 6 American Naturalist (1867) 2.6 24.9 7 Ecology (1920) 2.6 35.6 8 Ecological Applications (1991) 2.5 NA 9 Journal of Animal Ecology (1932) 2.1 27.8 10 Wildlife Monographs (1958) 2.0 NA 11 Microbial Ecology (1974) 1.8 17.5 12 Advances in Microbial Ecology (1977) 1.6 NA 13 Functional Ecology (1987) 1.6 NA 14 Oikos (Denmark: 1948; U.S.: 1980) 1.6 18.1 15 Conservation Biology (1987) 1.5 NA 16 Journal of Evolutionary Biology ('88)1.5 NA 17 Marine Ecology Progress Series (1979)1.5 23.7 18 Journal of Chemical Ecology (1975) 1.4 13.3 19 Oecologia (1924) 1.4 22.9 20 Evolutionary Ecology (1987) 1.3 NA Note: NA means information is not available. Years in parentheses are years in which the journal was established. Source: Institute for Scientific Information, Science Citation Index Journal Citation Reports, 1993 Although these researchers and their colleagues work in far- flung locales and on a menagerie of species, they have one thing in common: Their investigations are part of a relatively new marriage of fields--molecular and conservation biology. By applying such techniques as the polymerase chain reaction (PCR) and DNA fingerprinting, they use some of the smallest biomolecules--nuclear and mitochondrial DNA--to attack very large problems. Their research efforts are targeted at maintaining the biodiversity and understanding the life history and evolution of endangered species. "Each new technique [has] opened a new window on ecological and evolutionary processes," says Avise, a professor of genetics at the University of Georgia, referring to the rapidly accruing connections be-tween molecular and conservation biology over the last 15 years. Although environmental resear-chers have been involved in conservation activities for most of this century, only in the last 10 years or so has conservation biology as a discipline gained momentum. One indication of this is a relatively new professional society--the Society for Conservation Biology, which was formed in 1987 and already has more than 5,000 members. The society also produces one of the most highly cited journals in the field (see table at right). At the same time, writes Avise in his recent book Molecular Markers, Natural History, And Evolution (New York, Chapman & Hall, 1994), in the "late 1980s mitochondrial DNA analyses and DNA fingerprinting approaches gained immense popularity" in the fields of population genetics and evolutionary biology-- two fields closely allied to conservation biology. Most recently, he writes, the "introduction of PCR-mediated DNA sequencing has brought the field closer to a final technical fruition by providing the first ready access to the 'ultimate' genetic data, [the] nucleotide sequences themselves." Along with a bulging toolbox of molecular processes, researchers in this field bring expertise from a variety of backgrounds, including anthropology, population biology, ecology, genetics, evolutionary science, and zoo biology. And it is the goal of one new research initiative--the $6 million, Columbia University-based Center for Environmental Research and Conservation--to combine all these disciplines, as well as others. "The main reason for developing the center was to bring together the biological and social aspects of conservation biology," says Melnick, director of the center and a professor of anthropology and biology at Columbia. "Biology helps define the problem," he asserts, "but most of the solutions come from the socio-economic-cultural disciplines." While Columbia's center and others--such as a new University of Florida program, Biotechnologies for the Ecological, Evolutionary, and Conservation Sciences (BEECS)--function in an academic setting, other institutions collaborate with zoos. One joint project is the New Opportunities in Animal Health Sciences (NOAHS) Center in Washington, D.C., directed by the Smithsonian Institution's National Zoo and the National Institutes of Health. The center focuses on maintaining the genetic diversity of endangered species in zoo and wild populations and is codirected by Stephen O'Brien, director of the laboratory of viral carcinogenesis at the National Cancer Institute; Mitchell Bush, assistant director for animal health; and David Wildt, head reproductive physiologist, both at the National Zoo. "The whole field of conservation biology--before 10 years ago- -was pretty much dominated by field ecologists," O'Brien comments. "Then the conservation community discovered that maybe there were things you could see without looking through a pair of binoculars in short pants." The crossover between the fields of molecular biology and conservation biology covers many disciplines, including ecology, genetics, and evolutionary science. As a result, researchers in this field publish in a diverse array of journals and are represented in a variety of societies. A sampling of societies and their journals follows: American Society of Naturalists Montgomery Flatkin, president Department of Integrative Biology University of California, Berkeley Berkeley, Calif. 94720-3140 (510) 643-6300 Fax: (510) 643-6264 E-mail: monty@mws9.biol.berkeley.edu 2,800 members American Naturalist Mark Rausher, editor Department of Zoology Duke University Durham, N.C. 27706 (919) 684-2295 Fax: (919) 684-6168 E-mail: amnat@mendel.zoo.duke.edu Society for Conservation Biology Peter F. Brussard, president Department of Biology University of Nevada, Reno Reno, Nev. 89557 (702) 784-6188 Fax: (702) 784-1302 E-mail: brussard@scs.unr.edu 5,000 members Conservation Biology Reed Noss, editor Department of Fisheries and Wildlife Oregon State University Corvallis, Ore. 97331 Phone and fax: (503) 737-1940 E-mail: mainel@ccmail.orst.edu, for managing editor Ellen Main Society for Molecular Biology and Evolution Masatoshi Nei, president Institute of Molecular Evolutionary Genetics Pennsylvania State University 328 Mueller Lab University Park, Pa. 16802 (814) 863-7334 E-mail: nxm2@psuvm.psu.edu 850 members Molecular Biology and Evolution Barry Hall, editor Biology Department-River Campus University of Rochester Hutchison Hall Rochester, N.Y. 14627 (716) 275-3468 E-mail: bhall@bgh.biology.rochester.edu Society for the Study of Evolution Johanna Schmitt, executive vice president Department of Ecology and Evolutionary Biology Brown University Providence, R.I. 02912 (401) 863-3435 E-mail: jschmitt@brownvm.brown.edu 2,500 members (as of 1993) Evolution Geerat Vermeij, editor Department of Geology University of California, Davis Davis, Calif. 95616 (916) 752-3306/2234 E-mail: tacarson@ucdavis.edu, for managing editor Theresa Carson Some researchers say they became interested in conservation biology because of a long-standing interest in wildlife and nature. Avise notes that although his Ph.D. is in genetics, through his work in conservation biology, he's been able to "tie genetics back" to his "first love"--natural history. For example, Avise collaborates with his former Ph.D. student, Bowen--who is a team leader at BEECS--to study the migratory patterns, evolution, and genetics of green sea turtles using mitochondrial DNA as a genetic marker. Many geneticists now working with captive breeding programs in zoos report that they did not set out to become involved in conservation biology. Rather, they came upon this career path because of associations with colleagues who worked at zoos. Alan Templeton, a professor of biology and genetics at Washington University in St. Louis, says his involvement in conservation biology started when Bruce Read, a biologist at the St. Louis Zoo, approached him in 1979 to assist the zoo's Speke's gazelle breeding program. The gazelles are an endangered species found on the border of Somalia and Ethiopia. "The breeding program started with just four animals--one male and three females--which was all that was available at the time," recounts Templeton. "Many years later we found another source--the sheik of Qatar had a private collection. One of his cousins is a Somalian official, and he was able to go in and literally snatch a few animals out before the warfare got too bad." Templeton and Read then used DNA fingerprinting to determine the genetic relationship between the two groups of gazelles. Similarly, O'Brien says he was first introduced to conservation work through Wildt--his former postdoc--and Bush. "David [Wildt] was working with domestic cats, which I was also working on to develop models for cancer research. And, as an avocation, David collected and studied reproductive tissue from such nondomestic cats as tigers and cheetahs." >From this alliance, begun in the early 1980s, one of the first applications of biomedical techniques to conservation biology was brought about (S.J. O'Brien, "A role for molecular genetics in biological conservation," Proceedings of the National Academy of Sciences, 91:5748-55, 1994). By screening cheetah blood proteins and DNA, Bush, O'Brien, and Wildt found that cheetah populations had an extraordinary lack of genetic diversity--a result of inbreeding within a reduced cheetah population about 10,000 years ago, they surmise. They suggest that the low level of genetic diversity has caused reproductive problems--such as low sperm counts--for cheetahs in captivity and the wild. Molecular methods not only have begun to answer long-asked breeding questions for zoo biologists, but also have advanced the study of wild populations of animals. "Historically, conservation genetics involved very little mo- lecular biology because it's difficult to do genetics on wild populations and endangered species," says Phillip Morin, a conservation biologist and population geneticist who studied with David Woodruff, a professor of biology, and Jim Moore, an assistant professor of anthropology, at the University of California, San Diego. "So that's been a major stumbling block for people who have wanted to do genetics on wild populations. "We wanted to find ways to do molecular genetics that were noninvasive, allowing us to sample wild primates both without the difficulty of getting samples from the animals and having to freeze those samples in the field," recalls Morin, now a researcher at Sequana Therapeutics Inc. in La Jolla, Calif. Morin and others maintain that the development of PCR was a major breakthrough for their work. Morin, Woodruff, and Moore investigated the genetic variation of chimp mitochondrial DNA- -from hair found in the animals' nests--across Africa. They also used this approach to examine the genetic diversity in one very famous chimp community--the Gombe National Park population that primatologist Jane Goodall began studying more than 30 years ago. Stephen R. Palumbi, a professor of zoology at the University of Hawaii, also maintains that molecular processes have given conservation biologists a new way of studying animal populations. "Conservation biologists can count animals, they can tag them, and they can observe their social systems. But with all of that, there's still very important information about those species that you can't get. And genetics provides you with an independent and different way of examining the biology of those animals," observes Palumbi, who studies the population biology of humpback whales. For all of the advances that molecular biology is now credited with having brought to conservation biology, a genetic-level approach was not readily accepted by some conservation biologists at first. "When I first started out [in the late 1970s] there were very few geneticists active in conservation of any sort," Templeton recalls. "In fact, there was almost a kind of opposition by many of the professions in the field against genetics. They just didn't see how it was relevant." But, he notes, "the atmosphere is very different today." It is now common for genetic considerations to be included in planning captive breeding programs in zoos, training zoo staff, and writing management plans for maintaining endangered species. One way in which molecular methods aid endangered-species conservation is by helping to identify geographical patterns of genetic diversity, namely plotting the locations of subspecies and populations with similar genetic make-ups. Avise's book highlights biochemical techniques that are used to group these regional patterns. "This regional approach allows ecosystem management [preserving the environment and species of an entire habitat, rather than a single species] to be taken more seriously. And genetics can contribute to that perspective," suggests Avise. For example, Melnick and colleagues have been traveling to southern Asia to collaborate with the University of Indonesia and the Universiti Kebangsaan Malaysia to measure the biogeographical differences in genetic traits among such endangered species as Sumatran rhinos and orangutans across Borneo, Sumatra, Java, and peninsular Malaysia. This information will be used to make recommendations to wildlife agencies in Indonesia and Malaysia. And Nicholas Georgiadis, a conservation biologist at Washington University, is working with Templeton on a molecular genetic survey of large African mammals such as elephants and wildebeests, to chart the biogeography of genetic similarities within these species. Using biopsy darting to get blood samples, PCR, and sophisticated computer analyses, Georgiadis recently reported discovering two kinds of elephants in Africa--the savanna and forest types. This finding, he says, will have important implications for conservation plans concerning African elephant populations. Palumbi notes that this type of basic research "provides a springboard" for an emerging application of molecular conservation biology--molecular forensics, or genetic detective work. Palumbi and C. Scott Baker, a molecular ecologist from the University of Auckland in New Zealand, used a portable PCR device to test whale products sold in retail Japanese fish markets to determine from which species they were derived. By comparing mitochondrial DNA sequences to known samples in a databank, they found that a few of the 16 specimens tested may have come from protected species of whales. Similarly, Florida's Bowen and French colleagues from Lyon University discovered--by matching DNA from Florida loggerhead sea turtles with DNA from turtles drowned in the nets of Mediterranean commercial swordfishing boats--that 60 percent of the drowned turtles migrated from nesting beaches in the southeastern United States. This mortality rate helps explain the declining population of loggerheads in the U.S. Researchers point out that the application of molecular techniques--initially developed to aid biomedical research--to conservation has come full circle, and the knowledge accrued in these studies now has implications for biomedicine. Morin and colleagues, again using mitochondrial-DNA sequencing and advanced statistical analyses, estimate that about 1.6 million years ago a West African subspecies of chimpanzee became genetically distinct from other chimp populations. And it is this piece of information that Morin and colleagues propose may have ramifications for biomedical scientists. "If you use animals of different subspecies that have been evolving separately for over a million years, then you're really not using equivalent animals," explains Morin. "And that's one of the things that researchers want to control for. We're simply drawing attention to the fact that what is considered to be a homogeneous population in captivity is probably not, and this is significant enough that people who intend to use chimpanzees in biomedical research should consider this as an important variable in their experiments." Morin elaborates that chimps of different species may not react similarly in biomedical experiments, thereby adding a confounding factor to analyses of clinical study results. O'Brien sees an irony in the fact that biomedicine is now so intricately connected to conservation biology. "What I say in my lectures," he points out, "is that it's a little bit ironic that after studying animals to understand human biology for several hundred years, we now know so much about human biology--through the study of genetics, molecular structure, and physiology--that these approaches are now the model for [studying] endangered species."

Exotic Species, Locales All In Day's Work For Conservation Biologists

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