About the prize
Site map
Prizes awarded

The Crafoord Prize 1990 for fundamental contributions to Population Biology and the Conservation of Biological Diversity

The Royal Swedish Academy of Sciences has awarded Paul R. Ehrlich, Professor of Biology, Stanford University, USA and Edward O. Wilson, Professor of Biology, Harvard University, USA the 1990 Crafoord Prize, SEK 1,5 million.
Professor Paul R. Ehrlich for his research of the dynamics and genetics of fragmented populations and the importance of the distribution pattern for their survival probabilities.

Professor Edward O. Wilson for the theory of island biogeography and other research on species diversity and community dynamics on islands and in other habitats with differing degrees of isolation.

The two Crafoord Prize Awardees have obviously overlapping specialties and priorities. Both have devoted much of their lives to basic research on naturally fragmented populations and communities, and the insights that can be derived from their research have been put to a great deal of use in today´s conversation biology, the purpose of which is to stop the degradation of the world´s biological treasures. In addition to gaining positions as leading researchers they have also found time to become of international prominence as popular writers and experts at the service of decision makers at the highest levels.

Paul R. Ehrlich´s main research achievement within the sphere of this year´s Crafoord Prize concerns ecology and genetics of animal populations, which are subdivided into several or many smaller “subpopulations", either for natural reasons or as a result of human habitat alterations. Ehrlich´s favorite research object is a butterfly named Euphydryas edithae inhabiting high altitude habitats in the Rocky Mountains. As a result of decades if research Ehrlich and his tam have been able to analyze how various ecological and genetic factors influence the local and regional survival probabilities of this species in its mosaic habitat. Through his demonstration of the interplay of inner and outer factors, in particular, Ehrlich broke new ground and greatly contributed to the attitude now encompassed by most conservation biologists, namely that preservation of biodiversity means of not only species but also genetic variation. The principal conclusions from Ehrlich´s butterfly research on mountain tops in the Rockies have been of great significance also in other fields such as pest insect ecology and fisheries biology.

At least equally important has been another achievement of Ehrlich´s. In collaboration with botanist Peter H. Raven he advanced the theory of the co evolutionary relationships among species. The interrelation between two (or several) species may encourage the evolution of mutual adaptations eventually leading to obligatory symbiosis or mutual interdependence. Innumerable examples can be obtained from pollination biology where a plant species may be entirely dependent on the pollen transportation services of one particular insect species which in turn is dependent on that particular plant species for its food.

To the general public Ehrlich has become known as author (sometimes with his wife, Anne Ehrlich, as a co-author) of numerous books on global environmental problems, such as overpopulation, resource depletion, nuclear winter and greenhouse effects. It has been said that with Rachel Carson he is the one person with the greatest importance for present-day awareness of the imminent global environmental catastrophe.

Edward O. Wilson´s research achievement, that has made him one of this year´s Crafoord Prize Awardees, is this theory of island biogeography. In cooperation with Robert MacArthur (who died in 1973) Wilson advanced the hypothesis that the number of plants and animals species on islands might be explicable simply in terms of the size and degree of isolation of these islands, while the mechanism generating the diversity equilibrium would be processes of population biological characters operating within species. Given data on the size and remoteness of an island it would be possible to calculate its species diversity, and the calculations might then be tested against real data. This relatively simple idea transformed the study of species richness into a quantitative and experimental branch of biology and has proven extremely useful also with respect to “islands on land", such as, for example, remnant woodlands in an agricultural landscape, or vice versa. From the theory of island biogeography it is possible to predict, at least to some approximation, the faunistic and floristic losses to follow upon a habitat fragmentation caused by intensified human exploitation of an area. Arguably, hardly a single more important work in conservation biology is written today without the author making use of this theory as a launching ramp.

Among numerous other scientific achievement of lasting importance Wilson´s synthesis of the social behaviors of animals should be singled out. Viewing the behaviors as products of natural or sexual selection generated entirely new insights in central problems of evolutionary biology and brought together behavioral biology, genetics and ecology in a most fruitful cooperation. As a well known, the sociobiological syntheses provoked a lively debate whether evolutionary concepts and insights might be helpful also for the understating of certain human behaviors and habits.

In his whole life, but in the past decade in particular, Wilson has devoted an immense amount of time and energy to improve the general awareness of the accelerating decline of global biodiversity. He is and internationally highly respected expert in the field of conservation biology and serves as advisor to many a politician and international organization with responsibility for the management of the global natural resources.

A sum of SEK 800.000 from the Anna-Greta and Holger Crafoord Fund was also awarded Swedish research within population biology.

Professor Paul R. Ehrlich
(born 1932)
Dept. Of Biological Sciences
Stanford University
Stanford, CA 94305

Professor Edward O. Wilson
(born in 1929)
Museum of Comparative Zoology
Harvard University
Cambridge, MA 02138

Jessica Balksjö Nannini
Press Officer,
Royal Swedish Academy of Sciences
tel: +46 8 673 95 44
+46 70 673 96 50