1983 Balzan Prize for Zoology
Ernst Mayr (1904 – 2005) started his scientific career as an ornithologist, and in the years 1928-1930 he led three expeditions in various parts of New Guinea and the Solomon Islands. As curator of birds at the American Museum of Natural History, New York, and later as Alexander Agassiz Professor of Zoology at Harvard University he devoted himself to the study of the problems of evolution, particularly to the fundamental problem: the origin of species.
In his book Systematics and the origin of species (1942) he claimed that the traditional « typological » (essentialistic) concept of species can no longer be maintained today and in its place he proposed the « populationistic » concept, putting forward a definition of species which has since been largely adopted by biologists, namely, « species are groups of interbreeding natural populations that are reproductively isolated from other such groups. »
In developing the so called « synthetic theory » of evolution, which was formulated at the beginning of the forties, Mayr made an important contribution in bringing to light and exemplifying the naturalistic reality of the mathematical models of populationistic genetics.
He has rightly claimed that the definition of evolution as a change of gene frequencies, which had been accepted initially by the synthetic theory, is too narrow and hence inadequate. Natural selection acts, through the phenotype, on the whole genetic constitution of the individual: its target is not the single gene, but the whole genotype.
As to the origin of new species, Mayr has shown that the populations living at the periphery of the area covered by the original species may be isolated and so not able to maintain cohesion with the central population through gene flow. Hence they can pursue an independent evolutionary path which may lead to true « genetic revolutions » and give rise to new species. This process now designated « peripatric speciation » is accepted by the majority of evolutionary biologists. Mayr thinks that it is also of decisive importance in the origin of higher taxa.
In addition to his fundamental contributions to the revival and improvement of classical Darwinism, Ernst Mayr has devoted considerable attention to history and philosophy of biology. He has carried out a penetrating analysis of various aspects of the impact of Darwinism on modem thought. Especially original is his analysis of the concept of finalism in the light of the Darwinian interpretation. He has also emphasized the importance of animal behaviour, with its « closed » and « open » programmes, for the evolutionary process.
His last book The growth of biological thought (vol. I, 1982) is an excellent history of biology, in which he introduces the distinction between functional biology, the study of proximate causes, and evolutionary biology, the study of historical causes,
Ernst Mayr, the author of more than 500 papers and of ten original books, appears as one of the foremost contemporary students of biological evolution. Starting from zoological taxonomy he has made fundamental contributions to the study of the problems of evolution and of the theoretical impact of Darwinism on modern thought.