1997Basic SciencesBiological Sciences (Evolution, Behavior, Ecology, Environment)
Daniel Hunt Janzen photo

Daniel Hunt Janzen

  • U.S.A. / January 18, 1939
  • Tropical Biologist
  • Professor, University of Pennsylvania

Pioneering Study of Biodiversity in Tropics and Its Maintenance Mechanisms

As a pioneer of tropical biology, Dr. Janzen has formulated a large number of unique hypotheses, including mutualism for defense against predators and predation as a basis for biodiversity, making significant contributions to the flourishing of tropical ecology. Applying his special knowledge to practical situations, he has also been active in biological and environmental conservation in the tropics.


Brief Biography

Born in Milwaukee, U.S.A.
B.S. University of Minnesota, U.S.A.
Ph.D., Entomology, University of California, Berkeley
Associate Professor, University of Chicago
Professor, University of Michigan
Research Counselor, National Park Service of Costa Rica
Professor, University of Pennsylvania
Founded the Instituto Nacional de Biodiversidad, Costa Rica

Selected Awards and Honors

Gleason Award, American Botanical Society
Crafoord Prize, Swedish Royal Academy
Joseph Leidy Medal, Philadelphia Academy Natural Sciences
Silver Medal Award, International Society of Chemical Ecology
Fellow, American Academy of Arts and Sciences
Member, National Academy of Sciences U.S.A.
Decreed Honorary Member of the National Park Service of Costa Rica
Honorary Professor, Univeridad Nacional de Costa Rica

Major Works


Coevolution of mutualism between ants and acacias in Central America, Evolution, 1966.


Herbivores and the number of tree species in tropical forests,  American Naturalist, 1970.


Euglossine bees as long-distance pollinators of tropical plants, Science, 1971.


Sweep samples of tropical foliage insects: Effects of seasons, vegetation types, elevation, time of day and insularity, Ecology, 1973.


Tropical blackwater rivers, animals and mast fruiting by the Dipterocarpaceae, Biotropica, 1974.


(ed.) Costa Rican Natural History, Univ. of Chicago Press, 1983.


How to save tropical biodiversity? American Entomologist, 1991.


Pioneering Study of Biodiversity in Tropics and Its Maintenance Mechanisms

Working mainly in the tropical forests of Costa Rica in Central America, Dr. Daniel Hunt Janzen, a pioneer of tropical biology, has laid the foundation of today’s flourishing tropical biology, appealed to the academic world to realize the importance of tropical biology, and has opened the door to an extremely interesting field of science.

With his profound and extensive knowledge of tropical forests, Dr. Janzen has also been active in the conservation of tropical environments.

In recent years, information concerning tropical life has been compiled through intensive surveys at some research facilities in the tropics, resulting in the clarification of the statuses of numerous biological species existing in tropical forests, and their mutualism.

These findings have stimulated investigation of the tropical ecosystem and its evolution. Dr. Daniel Hunt Janzen is a pioneer and most active promoter in this field.

By demonstrating mutualism for defense against predators between acacias and ants and by hypothesizing predation as being the basis for the great biodiversity in the tropics, Dr. Daniel Hunt Janzen greatly influenced researchers grappling with the problem of cohabitation of multiple species in the 1970s, and promoted the development of tropical ecology. As the leader of modern tropical biology, he studied mutualism between bees and orchids, and also hypothesized that the simultaneous flowering and seed dispersal in some plants corresponds to their strategy for survival by satisfying the hunger of seed – eaters with rich food. Other unique hypotheses he formulated include those that explain “why tropical rivers are brown in color” and “why individual tropical trees of the same species are distributed away from each other.”

In the last half of the 1980s, Dr. Daniel Hunt Janzen became involved in a project to establish a national park in an area of forest which included an abandoned ranch in Guanacaste on the Pacific coast of Costa Rica, and also sounded an alarm bell to warn about the possible loss of tropical biodiversity. In 1991, the year before the “Earth Summit” at Rio de Janeiro, he pressured the Costa Rican government to found the National Biodiversity Institute (Instituto Nacional de Biodiversidad, INBio). The institute’s primary objective is to inventory all organisms of Costa Rica on the basis of specimens collected throughout the country. The institute has nurtured a large number of domestic researchers and technicians, and is also involved in DIVERSITAS, an international research program of biodiversity science.

In short, Dr. Daniel Hunt Janzen has not only stimulated the development of ecology and a wide range of other biological studies, but has significantly contributed to the understanding of today’s environmental problems, through his pioneer studies and unique and persuasive ideas and activities based thereon. For these reasons, The Inamori Foundation is pleased to bestow upon Dr. Daniel Hunt Janzen the 1997 Kyoto Prize in Basic Sciences.


Abstract of the Lecture

Gardenification of wildland nature and how to absorb the human footprint

I, my wife Winnie Hallwachs, hundreds of other biologists, and hundreds of thousands of wild tropical species, are deeply grateful to Dr. Kazuo Inamori and his advisors for having chosen to legitimize the conservation of tropical wildlands by granting it this year’s Kyoto Prize in Basic Science. I am here today to speak on behalf of tropical wildlands.

Where in the human genome can you comfortably place 235.000 wild tropical species? In the garden. Why 235.000 species, why so many? Because that is the size of those blocks of wildland biodiversity and their ecosystems that are sustainable. If we place those species anywhere other than in a human safe zone, they will continue in their downward spiral as grist in the human mill, just as they have for the past ten thousand years. My advice as a lawyer to wildland nature: if you can’t beat Oem, join Oem.

Can we directly blend several hundred thousand species of wild organisms into society’s sex drive? I doubt it. Likewise, I cannot imagine how to hide or integrate a couple of hundred thousand species of wild organisms, and all the things that they do to and with each other, in all those things we use for shelter. Feeding remains as the only hopeful refuge for our wildland biodiversity. We are hard-wired to be farmers, to be caretakers of our domesticates in their gardens. Gardens are forever.

How do we hide 235,000 species in the garden? We recognize wildland nature as a garden per se, with all the traits that we have long bestowed on a garden. And this, in turn, leads to the question of how do we absorb the human footprint. If we cannot absorb the footprints, even the most wellmeaning users will destroy the garden. And if we exclude those who leave footprints, our wildlands will not be gardens. Restoration.

Restoration biology is an old concept. It is omnipresent and it works. Anyone planning the sustainable use of a wildland garden has to recognize many different crops from one place, for many different kinds of users, with many kinds of footprints. How much can I harvest? That is to say, how big a footprint can my garden absorb? But there is one core difference between an agroscape and a wildland garden. It must remain a wildland garden into perpetuity, with the footprints being sustainably absorbed at many scales. And absorbing the footprints will mean, as a general rule, giving up on 5% of wild biodiversity and ecosystems for the indefinite survival of the 95% remaining. That is the price of being fitted into the human genome. There is no free footprint.

In closing.

I live and I study biology in one site in Costa Rica, side by side with a very large team of gardeners (http://www.acguanacaste.ac.cr). But I have chosen here to talk abstractly and of broad concepts. What matters is the goal of wildland survival into perpetuity D the specific actions are place-based, time-based, society-based. Abandon the goal, and no protocol, no convention, no law, no formula will succeed.

With today’s extension of the intellect through electronics comes the opportunity to do better basic science, but also to more selectively withhold knowledge. How will the balance play out with respect to the remaining tropical wildlands? Science and society are uneasy partners in the wildland garden: in the best of worlds we may achieve a very fine and finely negotiated partnership, and in the worst of worlds, annihilation of one by the other. A wildland garden with gentle trodding from caring gardeners just might achieve the partnership. A wilderness faces certain annihilation as a battlefield.

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Conservation of Biodiversity:Pratice and Theory

Wednesday, November 12, 1997
Kyoto International Conference Center
Toshisada Nishida, Professor, Graduate School of Science, Kyoto University; Member of the Prize Screening Committee Tamiji Inoue, Former Professor, Center for Ecological Research, Kyoto University
Norio Yamamura, Professor, Center for Ecological Research, Kyoto University


Greetings Toyomi Inamori
Managing Director, the Inamori Foundation
Greetings Junichiro Itani
Professor Emeritus, Kyoto University (Chairman of the Kyoto Prize Committee)
Lecture Takakazu Yumoto
Associate Professor, Center for Ecological Research, Kyoto University
Late Tamiji Inoue
"Pollination Ecology of General Flowering in S.E.Asian Tropical Forests"
Over the Blackwater
Lecture Edward Allen Herre, Research Scientist, Smithonian Tropical Research Institute
"Lessons from New World Figs and their Associates"
Lecture Hideo Miguchi
Assistant Professor, Faculty of Agriculture, Niigata University
"Seed Dispersal and Predation in Fagaceae"
Moderator Takakazu Yumoto
Lecture Tamaki Maruhashi
Professor, Faculty of Human and Cultural Sciences, Musashi University
"Primates and Mammals as Seed Dispersers in Tropical Forests"
Lecture Norio Yamamura
"Evolutionary Theory of Anti-Herbivore Defence"
Lecture Makoto Kato
Associate Professor, Graduate School of Human and Environmental Studies, Kyoto University
"Unique Flora and Fauna on Islands and its Conservation"
Introduction of the Laureate Hiroya Kawanabe
Director General, Lake Biwa Museum (Chairman of the Prize Screening Committee)
Commemorative Lecture Daniel Hunt Janzen,Laureate
"Arts and Science of Tropical Dry Forest Conservation through Non-Damaging Use: Area de Conservation Guanacaste, Costa Rica"
Symposium How to Conserve the Earth with High Biodiversity for the 21st Century
ChairpersonToshisada Nishida Panelists
Daniel Hunt Janzen
Edward Allen Herre, Takakazu Yumoto, Hideo Miguchi, Tamaki Maruhashi, Norio Yamamura, Makoto Kato