3 The New York Years (1931–1953)

200 5 Biological Species and Speciation—Mayr’s First Synthesis
mainly German, titles. This integration of North American and European systematic
research in clear and straightforward presentation, the interpretation of many
factsinthelightofmodernsystematicsandpopulationgeneticssoonextinguished
neo-Lamarckian and typological views in contemporary biology. Allopatric speciation,
population thinking, i.e., an emphasis on the “horizontal” (geographical)
componentofevolution,andthedemolitionofthetypologicalspeciesconceptwere
the general topics treated in detail. Additional aspects were geographically variable
polymorphism, clinal geographical variation, population structure of species, sibling
species, the biological species concept, and monotypic and polytypic species
taxa (it should be noted that the distinction between category, concept, and taxon
wasnotyetestablishedatthattime).Mayrpromotedanadaptationistviewof
subspecies and species differences, but stressed “the point that not all geographic
variation is adaptive” (1942e: 86). His volume includes a summary of his own 12
years of intensive taxonomic research in the spirit of new systematics, particularly
in the island regions of Indo-Australasia.
In his first chapter Mayr contrasted old and new systematics like this:
“Old”—the species and purely morphological views occupy a central position;
the individual, not the population, is the basic unit.
“New”—subdivisions of the species, subspecies, populations, individual and
geographic variation are studied in detail; the population or the “series” of the
museum worker has become the basic taxonomic unit. The morphological species
definition has been replaced by a biological one which takes ecological, geographical,
genetic, behavioral, physiological, biochemical, karyological and other factors
into consideration. The new systematist approaches his material more as a biologist
and less as a museum cataloguer, he attempts to formulate generalizations and
syntheses. He inquires into the nature and the origin of the taxonomic units with
which he works.
“The ornithologist knows his material so well that he can do what the geneticist
also does that is to pick out one particular character and study its fate under
the influence of geographical variation, and in the phylogenetic series. In the less
worked groups the taxonomist is forced to consider his taxonomic units as complete
entities and all he does is to arrange them in the most natural order. I think I shall
add that among the differences between the old and the new systematics” (Ernst
Mayr to Edgar Anderson, when preparing his Jesup Lectures, 28 January 1941;
HUGFP 14.7, Box 2).
Mayr also referred to the procedures of the species systematist (collecting and
analyses of the material, naming of populations and the selection of a type specimen)
and the rules of nomenclature. When, in early 1946, he sent copies of his
publications during war time to Erwin Stresemann in Berlin, he stated:
“A book came out here last year entitled The Reader over your Shoulder [by
R. Graves and A. Hodge]. It was a treatise on the technique of writing and on the
good usage of English. It emphasized that you should always write as if somebody
was looking over your shoulder reading what you put down. In a somewhat different
way you were always the reader over my shoulder. Time after time, when writing
my Systematics and the Origin of Species (1942) or my Timor report (1944e), it was